This year's El Niño will almost certainly become the strongest ever recorded, an analysis by a prominent climate researcher has warned. Though other scientists have cautioned that it's still too early to say what it will unleash.

Dynamical models now assign a 90% chance of the 2026-2027 El Niño being an all-time record event, sending temperatures in the Pacific Ocean up to around 3.6 degrees Celsius (6.5 degrees Fahrenheit) above average, according to an analysis by Zeke Hausfather, a research scientist at Berkeley Earth and an author of the Intergovernmental Panel on Climate Change's Seventh Assessment Report.

As the warm phase of a multiyear natural climate pattern, the El Niño could bring unprecedented temperature extremes to an already-warming world. The natural climate pattern is infamous for boosting global temperatures and fueling disruptive weather events such as floods and droughts.

A strong El Niño doesn't guarantee more severe weather impacts. The current El Niño models are also imperfect predictions of what's to come, and we won't know the true nature of this El Niño event until it peaks, likely later this year. However, forecasters have been warning of potentially supercharged El Niño conditions for months, and as more data emerges, there are more reasons to prepare.

According to projections by the World Meteorological Organization, the current El Niño — officially declared on June 11 — is on track to rapidly develop into a "strong" event between July and September. The National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center now predicts a more than 80% likelihood of very strong El Niño conditions taking hold by the end of the year, ranking this El Niño event among the largest in the historical record.

"These are striking forecasts," Emily Black, a professor of terrestrial processes and climate at the University of Reading and a senior scientist at the National Centre for Atmospheric Science in the U.K., told Live Science in an email. "El Niño forecasts always come with uncertainty, but the level of agreement between models at this time of year, combined with the observed warming already underway in the tropical Pacific, means this should be taken very seriously."

"The important point is that a very strong El Niño would substantially shift the odds of damaging weather in many parts of the world, particularly in the Global South — with severe impact on livelihoods," Black added.

The International Rescue Committee, a humanitarian organization, has warned that the intense El Niño conditions threaten to unleash severe flooding and drought across East Africa and Asia, hitting some of the most vulnerable communities, Al Jazeera reported Tuesday (July 14).

During El Niño, warmer waters gather east of the equatorial Pacific, forcing the jet stream south. In the U.S., this typically brings warmer, drier conditions to the Northeast, while the Gulf Coast and Southeast experience an increased risk of flooding. Globally, the net result of the warmer waters is more heat in the atmosphere, on top of the temperature rise from human-driven global warming.

"El Niño is a natural climate phenomenon, but it is now happening against the backdrop of a much warmer planet," Black said. "That matters because a strong El Niño releases heat and energy into an already warmed world."

"This does not mean every impact can be attributed simply to El Niño or simply to climate change," Black added. "The two interact. El Niño can load the dice towards drought in some regions, flooding in others, marine heatwaves, disrupted monsoons and unusually high global temperatures. Climate change makes many heat extremes more severe and can intensify heavy rainfall because a warmer atmosphere can hold more moisture."

The last El Niño event occurred between 2023 and 2024. Both years broke temperature records, with 2024 becoming the hottest on record and the first to breach the 1.5-degree- Celsius (2.7 degrees Fahrenheit) warming limit set by the 2016 Paris Agreement. The current El Niño is forecast to be more intense than the one in 2023 and 2024, with the projected "very strong" status putting it in a different class of severity.

The strongest El Niño in history?

Hausfather's analysis reports that there's around a 90% chance that the current El Niño will be the strongest ever recorded, with data from multimodel forecasts suggesting that it may obliterate the previous record.

"With the July runs now in from 667 ensemble members across 14 different seasonal forecast models, it looks like this year's El Niño is not only very likely to be the strongest event since reliable records began ‪—‬ it may end up the strongest by a truly mind-blowing margin," Hausfather wrote in The Climate Brink Substack post published Monday (July 13).

NOAA recognizes El Niño conditions when the eastern tropical Pacific Ocean is at least 0.5 C (0.9 F) warmer than the historical average, while wind, surface pressure and rainfall in the region are also consistent with El Niño conditions. The El Niño is then categorized as weak, moderate, strong or very strong. A very strong El Niño (above 2 C, or 3.6 F, warmer than the historical average) is often nicknamed a "super" El Niño, though it's not a scientific term.

The July models suggest that temperatures will likely sail past 2 C above average in the coming months and could potentially even exceed 3.5 C (6.3 F) above average by the end of the year. This is based on newly introduced sea surface temperature forecasts that account for rising background temperatures that can inflate El Niño warming figures. In the traditional and most widely used indices, the temperature-anomaly forecasts cluster closer to 4 C (7.2 F), with some even exceeding 4 C.

In The Climate Brink Substack, Hausfather noted that the multimodel median for the event's peak is currently forecast at 3.6 C (6.5 F), or around 0.8 C (1.4 F) hotter than the prior record holder (2.75 C, set in the 2015-2016 El Niño event). Hausfather wrote that around 91% of ensemble members (individual computer models) have this El Niño exceeding the 2015-2016 record at their peak — around 77% likelihood in the newly introduced indices.

However, Black stressed that the models are still estimates, and not guarantees.

"It is certainly plausible that this could become a record-breaking El Niño, and the latest forecasts make that a real possibility rather than a remote one," Black said. "However, I would still be cautious about treating any probability estimate as a certainty."

"There are two reasons for caution," she added. "First, this event has not peaked yet, and El Niño events usually reach their maximum strength later in the year. Second, 'strongest ever recorded' depends on the index, dataset and baseline used."

"Impacts are what matter"

The most severe El Niño events have left a trail of devastation in their wake. For example, the 2015-2016 El Niño saw a record-breaking hurricane season in the central North Pacific, severe drought in the Caribbean and Ethiopia, and, of course, abnormally hot global temperatures, according to NOAA's Climate.gov. If the forecasts pan out, the current El Niño will match or exceed the 2015-2016 event, as well as an even more infamous super El Niño that occurred between 1877 and 1878, long before modern recordkeeping of El Niño began in 1950.

The 1877-1878 event likely fueled an extreme drought that fed into the 1876-1878 global famine, which ultimately killed more than 50 million people — making it among the worst humanitarian crises in history. However, the disaster was far from just an environmental one, with extractive colonial agricultural policies helping to create conditions for a massive humanitarian crisis. Nonetheless, the famine highlights what can happen when environmental and socioeconomic factors converge.

Even though the world has changed a lot since the 19th century, experts have said a super El Niño could still cause severe shocks to our food systems. This is especially true at a time when researchers say food insecurity is not just confined to low-income countries and that climate change is already pushing agricultural systems to the brink.

The El Niño-Southern Oscillation cycle triggers a warm El Niño and then a cold La Niña roughly every two to seven years, with each phase typically lasting around nine to 12 months. Carbon Brief has predicted that 2026 is likely to be the second-warmest year on record, with the intensifying El Niño increasing the likelihood that 2027 will be the warmest year ever recorded.

The strength of an El Niño event does not necessarily correspond to the size of its influence or impact, according to the Climate Prediction Center. More severe events typically, but not always, increase the certainty of expected impacts. Black believes the impact of an El Niño event is more important than where it ranks in the observational record.

"Records are compelling, but impacts are what matter," Black said. "Even if it falls just short of a record, a very strong El Niño can still have serious consequences. Finally, these forecasts are concerning, but they are also useful: they give societies time to anticipate possible impacts and act before the worst effects are felt."

A giant blob of abnormally cold water in the North Atlantic Ocean is shifting the Indian summer monsoon, threatening the livelihoods of more than 1 billion people, new research suggests.

The link between these two systems highlights a previously unrecognized connection that could inform weather forecasts in South Asia and shed light on climatic events elsewhere, scientists say.

The Indian summer monsoon is a rainfall pattern that lasts from June to September and is driven by temperature differences between the warm northern Indian Ocean and cooler seawater below the equator. Historically, the monsoon triggered heavy rainfall along the west coast of India and a huge region of northern India called the Indo-Gangetic Plain. But since 1999, this pattern has changed dramatically, the researchers reported in a new study.

Northwest India now receives about 25% more rain during the monsoon season than it did before 1999, while the Indo-Gangetic Plain gets roughly 4% less, the team found. This is disastrous for farmers, in particular, because their soils and crops are adapted to the old rainfall pattern, said study first author Mahendra Nimmakanti, a climate scientist at the Indian Institute of Science's Centre for Atmospheric and Oceanic Sciences.

"India is largely dependent on agriculture," Nimmakanti told Live Science in a joint interview with study co-author Matthew Huber, a professor in the Department of Earth, Atmospheric, and Planetary Sciences at Purdue University in Indiana. Higher-than-normal precipitation in northwest India is causing flash floods and crop losses, because agriculture in this region is adapted to dry conditions. Meanwhile, the Indo-Gangetic Plain has seen periods of drought that also caused crop declines and impacted farmers' livelihoods, Nimmakanti said.

Previous studies have linked shifts in the Indian summer monsoon to changes in the Atlantic Meridional Overturning Circulation (AMOC), a giant web of ocean currents in the Atlantic that regulates the global climate and carries heat to the Northern Hemisphere. Data suggests the AMOC is slowing due to climate change and releasing less heat in the North Atlantic Ocean than it did before. This may be causing a southward shift of the Intertropical Convergence Zone, a band of low-pressure atmospheric conditions around the equator that drives tropical monsoons, including the Indian summer monsoon.

But these studies didn't specify how the Indian monsoon might shift or explain the underlying mechanism in detail, Nimmakanti said. "They generally explain that if there is a weakening of AMOC, that suppresses the Indian summer monsoon," he said.

One part of the problem is that current climate models do not show the changes in the Indian monsoon that have happened in real life, possibly because they also don't fully capture shifts in North Atlantic sea surface temperatures. This is especially true for a region southeast of Greenland known as the "cold blob," where the water was colder between 1901 and 2021 than it was in the late 1800s, even as the ocean around it heated up.

The cold blob suggests the AMOC is weakening because it points to a reduction in the amount of heat reaching the North Atlantic.

To pinpoint how and why the Indian monsoon has changed, the researchers fed precipitation data, sea surface temperature records and other real-life observations into dozens of climate models. This reproduced the shifts observed over the past 27 years. However, the results only implied a correlation between shifts in the North Atlantic and changes in the monsoon, not that the former directly caused the latter.

To figure out if North Atlantic sea surface temperatures caused the Indian monsoon to behave strangely, the team added and removed the cold blob in a simulation. The results showed that the cold blob has shifted the Indian monsoon by creating a strong temperature gradient over the North Atlantic, which, in turn, affects jet stream winds and pressure systems in the atmosphere above Eurasia.

Specifically, the jet stream above the North Atlantic has intensified, and a "blocking" system over the Ural Mountains in western Russia has strengthened, Huber said. As a result, weather systems in India have changed, sucking moist air toward the country's northwest and away from other regions.

"It's a shifting of the high- and low-pressure systems," Huber said. "Realizing that these two systems were directly linked through this wave train coming off the North Atlantic, that was novel."

More than 1 billion people in India and other parts of South Asia depend on the monsoon for food security and economic stability. The new results, published April 27 in the journal AGU Advances, could help forecasters predict extreme rainfall and drought events in India and neighboring countries like Pakistan during the monsoon season.

Some researchers think the Indian monsoon is a key tipping point within the global climate, and the findings suggest the system crossed a threshold in 1999. Since then, the cold blob has caused a "persistent jet stream reorganization," leading to abrupt shifts in the monsoon, according to the study.

It's unclear how the Indian monsoon will evolve under intensifying climate change, because climate models produce different predictions of what will happen in the North Atlantic, and other drivers may come into play as the world changes, Huber said.

"What we do now know is that this is one of the key building blocks of formulating a theory for what will happen in the future," he said.

It's official: El Niño is here, and it's shaping up to be among the strongest ever recorded.

The natural climate cycle, which supercharges temperatures and shifts weather patterns across the planet, officially took hold over the past month, according to a June 11 update by the National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center.

What's more, an accompanying average of various forecasting models gives a "63% chance of a very strong El Niño during November-January that would rank among the largest El Niño events in the historical record going back to 1950," NOAA officials wrote in the update.

This is no longer much of a surprise. Last week, the European Centre for Medium-Range Weather Forecasts, considered the "gold standard" of global weather models, suggested that this year's brewing El Niño would likely become the strongest ever recorded.

That prediction is increasingly shared by the world's best climate models, with about 75% of them now forecasting a record-breaking surge of at least 4.5 degrees Fahrenheit (2.5 degrees Celsius) above average sea surface temperatures across key parts of the Pacific Ocean, according to Europe's Copernicus Climate Change Service, with other model scenarios climbing as high as 7.2 F (4 C).

For reference, the past two strongest recorded El Niño events (2015-2016 and 1997-1998) sent ocean temperatures to 4.1 F (2.3 C) above average in the Niño 3.4 index, which measures sea surface temperatures across a key region of the Pacific Ocean.

What is El Niño?

El Niño events occur every two to seven years as part of the El Niño-Southern Oscillation (ENSO) natural climate cycle in the Pacific Ocean. The ENSO cycle flips between the warmer El Niño phase and the cooler La Niña phase, with neutral periods in between. El Niño periods bring elevated sea surface temperatures in the central and eastern Pacific, thereby weakening or reversing trade winds and strongly disrupting global temperatures and rainfall patterns.

Earth's last El Niño ran from June 2023 to April 2024, delivering an injection of heat to our already-warming world that made 2024 the hottest year on record. That year was also the first to breach the 1.5 C (2.7 F) warming limit — a key guardrail set by the Paris Agreement, beyond which the effects of climate change are predicted to become increasingly disastrous.

The current El Niño will also raise global temperatures this year and next, making it likely that Earth will reach, or even surpass, those previous records.

Now that El Niño's onset is official, scientists can advise people around the world on how to prepare. The impacts of this extra burst of heat stand to be profound, with studies linking previous El Niño periods to famine in Europe; civil wars in tropical regions; and droughts, floods and forest fires around the world. This year's El Niño will arrive during a period of already-increased global food insecurity driven by the Iran war.

And while El Niño would have occurred regardless, scientists are seeing signs that this El Niño's quicker-than-expected onset was driven by humanity's warming of the planet.

"It might be one of the most rapid transitions that I've seen in the record ‪—‬ maybe the most rapid," Nathaniel Johnson, a research meteorologist and member of the ENSO seasonal forecast team at NOAA, told Live Science in a May 1 interview. "Because, to go from a weak-to-moderate La Niña to a strong-to-very-strong El Niño within one calendar year is just not something we see very often."

"Over the past century, we have seen an increase in these more rapid swings from one state to the other," he added. "So there's some suggestion that potentially climate change could play a role in making these swings more rapid between El Niño and La Niña. It's something that will take more investigation."

This year's brewing El Niño will likely become the strongest ever recorded, a new forecast warns.

New predictions by the European Centre for Medium-Range Weather Forecasts (ECMWF) suggest sea surface temperatures in a key region of the central equatorial Pacific Ocean will climb 5.4 degrees Fahrenheit (3 degrees Celsius) above average by December of this year, with some scenarios showing they could go above 7.2 F (4 C).

If the forecast bears out, it means that this year's El Niño — the warm phase of a multi-year natural climate pattern that supercharges temperatures across the globe — will be significantly stronger than the previous joint record holders of 2015 to 2016 and 1997 to 1998.

Those past two El Niño events sent temperatures in the Niño 3.4 index (which measures sea surface temperature anomalies between 5 degrees north and 5 degrees south latitude, and 120 degrees west and 170 degrees west longitude) to 4.1 F (2.3 C) above average.

"Almost every scenario now reaches past +3˚C, with a cluster of high-end scenarios in excess of +4˚C," Ben Noll, a meteorologist and global weather writer at the Washington Post, wrote on the social platform X. "This outlook now depicts the strongest El Niño on record."

El Niño events occur every two to seven years as part of the El Niño-Southern Oscillation (ENSO) natural climate cycle in the Pacific Ocean. The ENSO cycle flips between the warmer El Niño phase and the cooler La Niña phase, with neutral periods in between. El Niño periods bring elevated sea surface temperatures in the central and eastern Pacific, thereby weakening or reversing trade winds and strongly disrupting global temperatures and rainfall patterns.

Earth's last El Niño ran from June 2023 to April 2024, delivering an injection of heat to our already warming world that made 2024 the hottest year on record and the first to breach the 1.5 C (2.7 F) warming limit — a key guardrail set by the Paris Agreement, after which the effects of climate change become increasingly disastrous.

The impacts of previous El Niño periods on global agriculture have been profound, with studies linking the events to famine in Europe; triggers for civil wars in tropical regions; and droughts, floods and forest fires around the world. This year's El Niño will arrive during a period of increased global food insecurity driven by the Iran war.

In an update on Tuesday (June 2), the World Meteorological Organization (WMO) warned that the climate pattern has an 80% chance of forming before September and a 90% chance before November, and that the world should prepare for a potentially strong event.

"The science is clear: El Niño is arriving on our doorstep in the coming months with 90% certainty. The world must treat it as the urgent climate warning it is," UN Secretary-General António Guterres said in a video statement.

And while El Niño would have arrived regardless of anthropogenic climate change, Guterres was careful to stress that it will add more heat to an already dangerously warming planet.

"El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther, and cross borders with devastating speed," he added.

"The only effective response is climate action equal to the crisis — ending the addiction to fossil fuels, accelerating the shift to renewables, protecting the most vulnerable, and delivering early warning systems for all."

This striking satellite snap shows a powerful hurricane bearing down on Hawaii as a shimmering silver streak obscures the tropical islands from view.

The swirling cyclone, dubbed Hurricane Kiko, was a Category 4 storm that formed in the eastern Pacific on Aug. 31, 2025. Three days later, on Sept. 3, it had fully strengthened, reaching peak wind speeds of around 145 mph (233 km/h), and made headlines after researchers realized it was on a collision course with Hawaii.

Luckily, the hurricane weakened to a Category 2 storm before reaching Hawaii and diverted to pass mostly north of the islands, before finally fading away on Sept. 10, just off the coast of Honolulu, according to Zoom Earth. These changes, which were brought about after the hurricane hit a patch of cold water, meant that residents experienced some heavy rainfall and high winds but were otherwise unaffected.

The satellite photo was snapped Sept. 7, when Kiko was around 600 miles (965 kilometers) east of Hilo on Hawaii's Big Island, according to NASA's Earth Observatory. At this point, the cyclone was approximately 470 miles (750 km) across at its widest point.

You can just about make out the outlines of the cloud-covered Hawaiian Islands within the thick band of silver stretching across the left side of the image. This shimmering streak is the result of a phenomenon known as a sunglint.

Sunglints are visible only from space. A sunglint occurs when sunlight bounces off the surface of the ocean or another large body of water directly into the observer's line of sight. (This is similar to how sunlight reflects off water during a sunset.)

The phenomenon gives water a metallic, mirror-like appearance, which can create stunning spectacles, such as reflected cloud murals and visually transformed rivers.

What's more, sunglints can partially obscure satellite imagery, thus interfering with efforts to monitor the climate, according to NASA. On the other hand, sunglints can help researchers by revealing hidden oceanographic phenomena, such as subsurface currents and "internal waves."

Researchers predict that, on average, hurricanes and other tropical storms will become more frequent and powerful in the coming decades as a result of human-caused climate change. In fact, there have already been signs of this happening in recent years, including storms such as Hurricane Melissa, which killed 95 people as it ripped through Cuba, Haiti, the Dominican Republic and Jamaica in October 2025.

See more Earth from space

Our warming world is set to enter an El Niño period as early as May, with a high likelihood of southern North America experiencing supercharged temperatures.

One of the three phases of the natural El Niño-Southern Oscillation (ENSO) cycle in the Pacific Ocean, El Niño events occur every two to seven years, driving up sea surface temperatures across the Pacific Ocean and increasing global temperature. The last El Niño partially explains why 2024 was the hottest year on record.

The knock-on effects of past El Niño events have been profound, with studies linking them to famine in Europe; civil wars in tropical regions; and droughts, floods and forest fires around the world.

And there's a good chance this year's El Niño will be particularly intense, with current forecasts indicating a 25% chance that El Niño will be "very strong" by November ‪—‬ meaning sea surface temperatures will rise by 3.6 degrees Fahrenheit (2 degrees Celsius) above average.

To get a better idea of what the upcoming El Niño will look like and what it could mean for Earth's climate and weather, Live Science spoke with Nathaniel Johnson, a research meteorologist and member of the ENSO seasonal forecast team at the National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center. Here's what he had to say.

Sophie Berdugo: How does NOAA predict and classify El Niño?

Nathaniel Johnson: Our basic classification of El Niño is based on the relative sea surface temperatures in this Eastern Central equatorial Pacific. And by relative, it means relative to the tropical average.

So, when the East Central tropical Pacific sea surface temperatures are more than 0.5 C [0.9 degrees Fahrenheit] above the tropical average, then we have El Niño conditions.

We can further subdivide El Niño into weak, moderate and strong. So that's more of an unofficial subdivision just based on how warm the ocean surface is in the east central tropical Pacific.

SB: What are the thresholds for those unofficial subdivisions, and how rare is each category?

NJ: El Niño is declared when the Relative Oceanic Niño Index — that's a measure of the ocean temperatures in the east central tropical Pacific box — is more than 0.5 C above the tropical average.

So between 0.5 C and 1 C [1.8 F], that would be a weak El Niño. El Niño, on average, occurs about every three to four years. Many times, it's a weak El Niño. If this index is between 1 C and 1.5 C [2.7°F], then we say it's a moderate event.

If it's 1.5 C to 2 C, we consider it a strong event. And then above 2 C is a very strong event. A very strong event is the sort of event that happens maybe once every 10 to 20 years.

What is the current forecast for the upcoming El Niño, and how certain is it?

NJ: Currently, NOAA predicts about a 90% chance that El Niño will develop by this fall. Usually, it's more difficult to make a forecast for El Niño in the spring: we have a so-called spring predictability barrier where forecasts tend to be less confident in the spring. So the fact that NOAA predicts a 90% chance is unusual for this time of year.

And there's about a 50% chance that it will at least be a strong event ‪—‬ (so, again, that index above 1.5°C ‪—‬ and about a 25% chance that'll be a very strong event, so above that 2°C.

There's still a lot of uncertainty about how strong this event will be. But I'd say it's still unusually confident that we will have an El Niño given that, this time of year, it's often difficult to be very precise about our El Niño forecast.

SB: Why is it tricky to forecast this time of year? And what does the fact that we've already got quite a high certainty that it's coming mean for this impending El Niño?

NJ: El Niño requires cooperation between the atmosphere and the ocean, so there has to be certain feedbacks between the tropical atmosphere and ocean. And coupling between the ocean and atmosphere is weaker this time of year, just because of seasonal changes in the average sea surface temperature.

So, for example, there's less of an east-west contrast between the Western Pacific and the Eastern Pacific. And that contrast between the East and West is what's important for this coupling between the tropical atmosphere and ocean.

So what that means is that it's easier to disrupt the development of an El Niño by just chaotic weather. So things that we cannot predict more than a few weeks in advance, for example, if we suddenly had strong winds coming from the East to West, that could help disrupt an El Niño.

The fact that we're this confident that El Niño will develop just tells us that, despite these uncertainties, despite the compounding impacts of the chaotic weather, the conditions are really well aligned for this El Niño to develop. We haven't seen anything, any signs that this progression is being disrupted. Everything so far seems to be aligning with this rapid change from the La Niña conditions we had last boreal winter [winter in the Northern Hemisphere]. We're now neutral, but the Eastern Pacific is warming up pretty quickly right now.

SB: Is it unusual how rapidly we've got this new El Niño approaching?

NJ: Yes, it is actually pretty unusual. The other way around is not so unusual. It's actually pretty common to go from, say we have a strong El Niño, to rapidly transition to a La Niña. But the other way around, going from a weak to almost moderate La Niña into El Niño and potentially a strong El Niño, that is more rare.

And, in fact, if this does turn out to be a very strong El Niño, it might be one of the most rapid transitions that I've seen in the record ‪—‬ maybe the most rapid. Because, to go from a weak-to-moderate La Niña to a strong-to-very-strong El Niño within one calendar year is just not something we see very often.

SB: So what could be causing that?

NJ: It's something that's going to have to be diagnosed after the event if it does turn out that way.

I'll just note that over the past century, we have seen an increase in these more rapid swings from one state to the other. So there's some suggestion that potentially climate change could play a role in making these swings more rapid between El Niño and La Niña. It's something that will take more investigation.

SB: What impact could a very strong El Niño event have on climate and food systems this year?

NJ: If we did have a very strong El Niño, it would have, for example, impacts on our fisheries. If we had a very strong El Niño, we could have a collapse of the Eastern equatorial Pacific "cold tongue," so that would reduce the amount of nutrient-rich water that gets upwelled. [Editor's note: The Eastern equatorial Pacific "cold tongue" is a nutrient-rich body of surface water in the Pacific Ocean.]

That would have potentially a very significant negative impact on, say, anchovy fisheries in Peru. We tend to see a migration of warm-water fish to warmer waters, like tropical fish migrating northward or to the West Coast of North America. Maybe cold-water species may see a decline of fish like salmon.

We see, potentially, negative impacts on crops where there's drought, so places like from Indonesia to Australia to northern South America tend to have drought. Those are some of the big impacts on food.

The wildfire risk would be increased over places including Australia, Indonesia, northern Brazil, parts of maybe western Canada and northern U.S., where the conditions are expected to be drier.

A very strong event just generally means much warmer tropical waters in general. So, coral bleaching could potentially be quite severe. So it's a lot of potentially strong ecological impacts from a very strong event.

SB: The most recent El Niño lasted from 2023 to 2024, and 2024 became the hottest year on record. What can we expect in terms of global temperatures for this upcoming El Niño?

NJ: El Niños tend to bring a temporary spike in the global mean temperature. If it turns out to be a strong event, then that would tend to be an even bigger spike on top of the long-term warming trends. So, if we were to have a stronger El Niño, then it would just increase the likelihood that we could have a new record in global mean temperatures.

SB: What will the impacts be on the U.S., parts of which are already facing severe drought conditions even before summer?

NJ: The impacts on the U.S. would tend to be strongest in our winter, although beforehand, the first notable impact would be on the hurricane season. Typically, during El Niño, we see a suppression of the Atlantic hurricane season and an enhancement of the Eastern Pacific season — so overall, maybe a reduced risk of tropical cyclones in the summer and fall.

But then, typically in the winter, we see enhanced rainfall and snowfall over the Southern tier of the U.S. So that would be potentially good news for the drought-stricken regions of the Southern part of the U.S.

But that shift to the storm track south would mean that drought in the more Northern areas may persist. So it would enhance the probability of persisting drought over the Northern parts that have been affected.

SB: So could El Niño bringing heightened winter rainfall to drought-stricken Southern parts of the U.S. lead to a greater risk of flooding?

NJ: Drought relief obviously would be great, but there is a potential heightened risk of floods. Particularly if we have a strong to very strong event, what we see is that the subtropical jet stream gets extended more to the East, more towards the North American continent. That could lead to more frequent, say, atmospheric rivers over parts of the West Coast — places like California.

And those atmospheric rivers, of course, bring beneficial rain and snowfall ‪—‬ you know, snowpack to the Midwest‪ —‬ but they also bring flooding and destruction from winds. And so there's always both positives and negatives that they can potentially counterbalance each other.

SB: What should people and governments do to prepare?

NJ: I think, at this point, they [should] just prepare for the enhanced risks that are associated with an El Niño of various strengths ‪—‬ understanding that there's still uncertainty in terms of the amplitude, as I mentioned, but there is a potential for a strong to very strong event. All these risks that are associated with El Niño, just be prepared to devote the resources necessary to address those risks.

Again, it's not certain — there's always other factors — but the stronger the event, the more likely it is that this El Niño is going to dominate over the other factors that could be influencing our weather and climate.

SB: There's been a lot of talk about there being a "super" El Niño and what the potential impacts will be. What is your closing message to readers?

NJ: I guess my message would be to try to filter out the hype and just focus on the solid science. Have a rational viewpoint of the forecast, which is, an El Niño is likely; there's still uncertainty in terms of how strong it will be. Just be aware of the potential impacts that may come, and note that we're going to continue to fine-tune the forecast in the months ahead.

Editor's note: This interview has been condensed and edited for clarity.

El Niño is forecast to return as early as May, which could bring above-normal temperatures to almost everywhere on Earth, according to a new report.

El Niño events occur every two to seven years as part of the El Niño-Southern Oscillation (ENSO) natural climate cycle in the Pacific Ocean. The ENSO cycle flips between the warmer El Niño phase and the cooler La Niña phase, with neutral periods in between. El Niño periods bring elevated sea surface temperatures in the central and eastern Pacific, thereby weakening or reversing trade winds and strongly disrupting global temperatures and rainfall patterns.

In a Global Seasonal Climate Update published April 21, the World Meteorological Organization (WMO) reported that El Niño is set to develop during the May to July season. Although the confidence of the prediction will improve after April, models currently suggest this El Niño could be a "strong event," according to the WMO.

"After a period of neutral conditions at the start of the year, climate models are now strongly aligned, and there is high confidence in the onset of El Niño, followed by further intensification in the months that follow," said Wilfran Moufouma Okia, chief of climate prediction at the WMO.

The impacts of El Niño periods on global agriculture are profound, with studies linking the events to famine in Europe; civil wars in tropical regions; and droughts, floods and forest fires around the world.

The most recent El Niño period lasted from May 2023 to March 2024 and contributed to 2024 being the hottest year on record.

Now, the Global Seasonal Climate Update predicts a "rapid warming trend" for May, June and July. Elevated temperatures are highly likely in southern North America, Central America, the Caribbean, Europe and Northern Africa.

Rainfall patterns will shift greatly across the world. Some parts of North America could get wetter, but the lack of a clear signal means it's currently unknown.

In March, the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center announced that there was a 62% chance of El Niño emerging between June and August. NOAA has since said there's a 61% of El Niño returning in May to July and continuing through the rest of the year. The WMO does not use the term "super El Niño," but NOAA predicts a 25% chance of a "very strong" El Niño beginning in November.

The WMO will publish a revised El Niño update in late May.

Florida is experiencing its most intense drought in 15 years, with more than 70% of the Sunshine State facing what the U.S. Drought Monitor calls "extreme" to "exceptional" drought conditions.

Northern Florida is suffering the driest conditions in the state, and recent rainfall has brought almost no relief, according to the latest drought data. Forecasts show no rain and high temperatures over the next week, so the situation will likely get worse before it gets better, experts told Live Science.

"Dry conditions have been building throughout the winter," Esther Mullens, an assistant professor of geography at the University of Florida, told Live Science in an email. "Three months ago, 98% of the state was in unusually dry conditions, however only 4% were in severe to exceptional drought. As of currently, this number has risen to over 71% in severe to exceptional drought."

Here's everything you need to know about Florida's drought, including how it got to this point, how long it will last, and what the impacts will be.

Why is Florida in a drought?

Florida, along with Georgia and other parts of the U.S. Southeast, currently sits beneath a ridge of high atmospheric pressure that has moved in and out of the region since fall last year but remained stationary since March. This means the air above the Southeast is sinking and compressing, which reduces humidity and prevents cloud formation.

"Rain cannot form in sinking air so it just stays warm and dry," Pam Knox, an agricultural climatologist at the University of Georgia and the director of the Georgia Weather Network, told Live Science in an email.

Clear skies have dominated for weeks over Florida and other parts of the Southeast. But it's not just high pressure that's driving the current drought, because rainfall has been below average for months. Florida was unusually dry for much of last year, and many areas have received less than 50% of their normal rainfall since Sept. 1, 2025, according to the National Weather Service.

"That means they are about 20 to 25 inches [50 to 65 centimeters] below what would be considered average rainfall," Knox said.

Months of dry weather were followed by a La Niña winter, which shifted the jet stream northward. This brought colder, wetter conditions to the northern U.S. and Canada, while the southern U.S. became warmer and drier.

"The combined effects of the lack of tropical storms last year with the La Nina over the winter, which is usually a time of warmer and drier climate than average, have helped lead to this current situation," Knox said.

Why is the current Florida drought so bad?

The current drought in Florida differs from previous bad droughts because it has hit in spring instead of summer. The last time the U.S. Drought Monitor recorded such exceptionally dry conditions in the Sunshine State was June 2011, but it has not been this dry so early in the year since 2000, Knox said.

While the La Niña, low precipitation, and fewer storms this season are attributable to natural variability, global warming and shifts in the water cycle caused by higher temperatures may be contributing to the dryness, Knox said.

The impact of climate change is difficult to disentangle from natural variation without proper attribution studies, Mullens agreed.

How long will the Florida drought last?

Current drought conditions in Florida will probably worsen until the end of April, but they are expected to improve slightly in May as the high-pressure area in the atmosphere moves away from the Southeast.

"In the Southeast, the worst drought is in northern Florida and southern Georgia, but other areas are likely to get worse over the next couple of weeks with high temperatures and no rain in the forecast," Knox said. "We expect the weather pattern to change around the end of the month as the high pressure shrinks off to the east, which will allow cold fronts that could produce rain to enter the Southeast again."

It's unclear how conditions will evolve through summer, but a lot of moisture will be needed to end the drought. Ideally, a tropical storm or a stationary front should bring enough rain in the coming weeks to quench plants and replenish soil moisture.

"It is difficult to get out of drought in summer because the plants and evaporation tend to use every bit of rain that falls," Knox said.

A strong El Niño is on the horizon, which could bring wetter weather this summer, Mullens said. But a clear picture of this year's drought will emerge only once it's over, when scientists will be able to more accurately compare its length with droughts that struck Florida in 2000 and 2011.

What are the impacts?

Satellite data shows that shallow groundwater aquifers have dried up across the U.S. Southeast during this year's drought. That's because more water has been extracted from these aquifers than usual to irrigate farmland and provide drinking water for people under exceptionally dry conditions.

In Florida, aquifers are especially dry in the northern and central regions. Aquifers do not immediately recover from drought, because rainfall first has to wet the entire soil column before it can trickle down to replenish groundwater stores.

"Aquifers are considered to be a lagging indicator of drought because they get worse after the drought is bad at the surface and it takes them longer to recover," Knox said.

The drought has been felt across Florida, with some water districts imposing restrictions on water use for certain activities such as lawn irrigation. Dry vegetation has also provided ample fuel for wildfires, including a blaze in February in Big Cypress National Preserve, about 25 miles (40 kilometers) east of Naples. And even the Everglades are facing unusually dry conditions, news reports show.

If the drought lasts much longer, there will be more wildfires and possibly even water shortages, Knox said.

It might take several weeks of consistent rain or a tropical storm lasting multiple days to recover from this drought. Ideally, precipitation should be abundant but not come all at once; soils have limits on how much water they can absorb, and the surplus would likely run off, Knox said.

"Florida soils are generally pretty sandy so if it is really dry, they could probably absorb 2 [to] 3 inches [5 to 8 cm] easily over a few hours," she said. "Other areas in the Southeast with more clay soil would not be able to absorb as much."

Farmers, in particular, are desperate for rain. "In all my years of farming, I've never personally experienced a spring this dry," Shannon Nixon, a soybean and peanut farmer near Baker, Florida, told Farm Progress. "To be this dry this early in the spring is very concerning."

The drought may take a huge toll on farmers' income, as many have likely delayed planting crops or decided not to plant crops at all for fear of them dying, Knox said. And if these dry conditions persist, consumers will also be affected, because food production will decrease locally and some of it will not be made up by imports.

"That will mean shortages of some products that are produced locally like vegetables," Knox said.

Tornadoes produce the fastest wind speeds in the world and can cause monumental destruction. In 2008, atmospheric scientist Perry Samson was conducting field research on supercell storms in Oberlin, Kansas, when he got a much closer look at these devastating weather phenomena than he expected — and got dragged into a tornado.

Samson, professor emeritus of atmospheric science at the University of Michigan, was on a teaching trip, helping students learn how to make measurements and observations. He'd set up a foundation so students could go and study these thunderstorms in the field, giving them the chance to learn how to conduct large field studies.

As they were carrying out their observations, a tornado formed from a supercell nearby and began moving toward them.

A supercell is a thunderstorm with a persistent rotating updraft. If the updraft is being fed by warm, moist air at ground level, it can turn into a tornado — but this is relatively rare. Around 20% of supercell storms end up as tornadoes, according to the National Oceanic and Atmospheric Administration's National Severe Storms Laboratory.

"Your chance of seeing one is very low, really," Samson told Live Science. "You just try to position yourself [in] places where you think that something could happen and be flexible enough to move from there. We positioned ourselves near Oberlin that day."

Live Science spoke with Samson about what it's like to end up inside a tornado and survive.

Hannah Osborne: How quickly did the tornado form, and at what point did you realize you were in trouble?

Perry Samson: We could see there was some motion inside these clouds which could produce a tornado. It formed to our south, and we immediately realized that the winds in the upper atmosphere were from south to north and so this thing was going to be moving towards us. Despite all the training we've been through, all the preparation we've gone through, realizing a tornado is bearing down, you sort of freak out.

My biggest concern was obviously making sure the students are going to be safe. We thought we'd drive to the east to get out of the way. And my students made it out of the way, but I wasn't as fast as they were.

HO: What were you thinking at this point?

PS: I wound up getting caught in the debris to the point that I could not see even the front of the car. It was so much debris flying, and I realized that I was now near the core of the tornado. I was thinking, I've been training, studying these things myself ‪—‬ so I knew the wind flow and how the wind is going to move. So I tried to position the car to take advantage of the aerodynamics of the vehicle, and this is the point where I always have to do a shout out for the Chevrolet Cobalt. The car has excellent aerodynamics, so I pointed it into the wind as best I could.

You should also understand that I'm from a family of meteorologists. My sister and my brother are also meteorologists. So for me, this was exciting. But I also knew the dangers and things were slamming against the windshield and vibrating and flying off debris of all kinds ‪—‬ sticks, twigs, everything. And I thought, "Oh my God, is there a cow in this field? I've seen the movies. What a horrible way to die."

I tried to take a picture, because I also offered, jokingly, in my courses, the first student who could get a video looking straight up the insides of a tornado, I would give an instant Ph.D. to. Of course, they'd have to live long enough to write it up. So, knowing that joke, I tried to take a picture. It was funny, but it was so black inside that the camera wouldn't work. I couldn't take any pictures inside the tornado, so I just hunkered down on the front seat, got as low as possible, expecting the car was going to get bashed.

Thank God, the storm passed over me. And I got out, and the car was embedded with straw in every crack. Between the door and the window, anything, just straw embedded straight into the car. The front roof of the vehicle was actually lifted a little bit off the car. We just went to the next town, and we took her through the car wash.

HO: What did the car rental company say when you brought the car back?

SP: You know, I forgot to mention that. They asked, "How was the car, good?" I said, "Oh it worked very well; thank you."

HO: When you were in the middle of it, was it completely different to what you imagined being in a tornado would be like?

SP: I've never thought about it, but if the tornado's been on the ground for more than a couple of minutes, it's going to be picking up soil and straw and whatever's in the path of buildings. That's the greatest danger right there, flying debris. In fact, we teach our students, if your car is in the path, get out of the car and get into a ditch. ‪But you want to be as low to the ground as possible because the wind speed is lowest at the surface.

I tried to open the door, [but] the power of the wind was such that we could not even get the door open. So I said, "I've done everything wrong." It's one of those moments where you think, 'Yeah, I should have been more religious."

HO: From the start of realizing, "I'm not getting out of this" to when it finished, how long was that?

SP: It wasn't long. I mean, it seemed long at the time. But I think it was ‪—‬ well, in fact, I know ‪—‬ it was less than a minute, because we had data. Our cars were measuring wind speed, wind direction, pressure, humidity, all this. We could see the winds, the pressure change, was significant.

It would be like you're in an elevator going from the bottom to the top of a 20-story building in 10 seconds. So it's quite a pressure change, and you notice that. And both as it goes down, it comes back up again. But beyond that, the wind speeds were somewhere close to 200 miles an hour [322 km/h], we estimate, based on our measurements. It's hard to describe it; it's just such a fast change.

[With] a hurricane, you know it's coming for days. You know it's going to happen. But this, you got, I would say it was a minute. It was a minute from when it began to when it was over.

HO: What was your first thought when it ended?

SP: The first thing I did is, I called my colleague from Texas Tech University, and he claims he still has the recording of my voice, which was a mix of fright and enthusiasm: a), I almost killed myself with b) Holy cow, this is what it looked like inside.

I think he just felt sorry for me because I put myself in such a terrible situation and the students in a terrible situation.

HO: Did that experience change how you looked at tornadoes and the work you were doing on them?

SP: I taught a class for many years, and it was called "Extreme weather and climate change" ‪—‬ and issues on the table were, how will extreme weather events change in a warming climate? So I can bring these videos of the experience and stories to the classroom, and it made the conversation more engaging, I think, for the students to be able to ask questions about it, more details of what it's like in these storms.

It didn't affect my research, but my research really isn't on extreme weather. That's just a passion. To this day, I get asked all the time to come and give a talk because it's so foolish, people want to hear it over and over again.

We continued doing the [student field trip] for the next several years. It continued, in fact, to set up a whole endowment at my university, so after I retired, they had the resources to be able to go and send students out ‪—‬ not necessarily storm chasing. I've also taken teams of students to the innards of Greenland, where we make atmospheric measurements related to climate changes, get the students out into the field, give them the opportunity to discover more than just the science, the passion for this field.

HO: But you wouldn't recommend going into a tornado?

SP: Absolutely not, no.

Editor's note: This interview has been condensed and lightly edited for clarity.

Forecasters predict that a potentially supercharged El Niño is coming this summer, and it could push temperatures across the globe to unprecedented extremes.

Last week, the National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center announced that there is a 62% chance of El Niño emerging between June and August. In other words, El Niño is more likely than not this year.

El Niño is the warm phase of the El Niño-Southern Oscillation (ENSO), a natural climate pattern of atmospheric and sea temperature changes in the tropical Pacific Ocean. During El Niño, warmer waters gather east of the equatorial Pacific, forcing the jet stream south. This brings warmer and drier conditions to the northern U.S., while the Gulf Coast and southeastern U.S. have an increased risk of flooding.

The tropical Pacific Ocean is currently in the midst of La Niña, the cold phase of ENSO, when sea surface temperatures fall at least 0.9 degrees Fahrenheit (0.5 degrees Celsius) below the long-term average. La Niña is expected to end in the coming weeks as the sea warms, according to the latest Climate Prediction Center announcement. El Niño will then occur if sea surface temperatures reach and remain at least 0.9 F above the long-term average.

If El Niño does emerge as anticipated, it could intensify into a "super El Niño," AccuWeather reported. A super El Niño occurs when sea surface temperatures reach at least 3.6 F (2 C) above the long-term average.

"Intensity is uncertain but there is potential for a moderate to possibly strong El Niño this fall into winter," Paul Pastelok, a meteorologist and lead U.S. long-range forecaster at AccuWeather, said, per the weather website.

Accuweather's forecasters estimate that there's a 15% chance of a super El Niño developing by the end of the hurricane season in November. Meanwhile, NOAA's Climate Prediction Center gives a 1-in-3 chance of a strong El Niño emerging between October and December but describes the potential strength as "very uncertain."

El Niño tends to strengthen hurricane activity over the central and eastern Pacific while suppressing hurricanes in the Atlantic, which typically leads to a less-active hurricane season overall.

The ENSO cycle triggers a warm El Niño and then a cold La Niña every two to seven years, on average. However, they aren't always on time. Equally, while each phase tends to last around nine to 12 months, their duration varies.

Earth was last in El Niño between May 2023 and March 2024. On that occasion, El Niño was close to being a super El Niño, but while sea surface temperatures breached the 3.6 F threshold, they didn't remain above the threshold for long enough to qualify. The last super El Niño occurred in 2015-2016.

The last El Niño contributed to record-breaking heat in 2023 and 2024, with 2024 currently the hottest year on record. If El Niño emerges in 2026, then the year will get warmer, but is unlikely to be as hot as 2024 — we started the year in La Niña, after all. Global temperatures in 2027, however, could be pushed to record-breaking heights, according to a post on the social media platform X by Zeke Hausfather, a climate scientist and energy systems analyst.

"The El Nino cometh," Hausfather wrote. "This would push up our estimate for 2026 global temperatures (though its still unlikely to surpass 2024 as the warmest year), and make 2027 very likely to be the warmest year on record given the historical lag b/w ENSO and surface temp."

It's important to remember that a variety of factors influence the weather and climate. The planet is already warming due to climate change and will continue to do so, regardless of what ENSO is doing.

On October 6, 1970, the deep-sea drilling vessel Glomar Challenger returned to port in Lisbon, Portugal, bearing a cargo that would revise history. During its 54-day voyage, the Challenger had punched 28 holes into the bottom of the Mediterranean Sea. The recovered cores pointed toward a startling conclusion: About 6 million years ago, the sea had turned into a desert: a vast, barren, salt-filled bowl more than two kilometers [1.2 miles] deep. Half a million years after that, the Atlantic Ocean had burst through what is now the Strait of Gibraltar and unleashed the largest flood in history.

Kenneth Hsü, an oceanographer who was one of the two lead scientists on the Challenger expedition, imagined the scene vividly in the December 1972 issue of Scientific American:

"Cascading at a rate of 10,000 cubic miles per year, the Gibraltar Falls would have been 100 times bigger than Victoria Falls and 1,000 times more so than Niagara.… What a spectacle it must have been for the African ape-men, if any were lured by the thunderous roar."

The catastrophe story was a hit: David Attenborough filmed a documentary about it, and Gibraltar even issued a 5-pence stamp portraying the "3,000-metre waterfall." The two hypotheses — first, that the Mediterranean Sea became landlocked during a half-million-year period known as the Messinian salinity crisis, and second, that it was restored by a cataclysmic deluge through the Strait of Gibraltar, dubbed the Zanclean flood — have been conventional wisdom among geologists for more than 50 years.

However, fresh doubts have arisen recently about every part of this story, from the mega-desert to the mega-Niagara. Many geologists have argued for a much briefer desiccation followed by a far more gradual refilling of the Mediterranean. Some think that the Mediterranean never completely disconnected from the Atlantic at all. "The idea of a megaflood, and the data that supports it, are mostly flawed," says Guillermo Booth Rea of the University of Granada in Spain.

The most startling recent twist is that the floodway, if there was one, may not have been anywhere near the present-day Strait of Gibraltar, which separates southern Spain from Morocco. For 50 years, new research suggests, we have been looking for signs of a megaflood in the wrong place.

A geological conundrum

In the present-day Mediterranean, about three times more water is lost every year to evaporation than is recaptured from rainfall and rivers. The Atlantic makes up for the difference, supplying a steady west-to-east current of seawater through the Strait of Gibraltar. As the sea's water evaporates, the remaining water becomes saltier and denser and sinks to the bottom. The dense water then flows back out of the strait, east to west, underneath the less dense inbound water. This outflow prevents salt from accumulating in the Mediterranean.

But what would happen if the strait were constricted, or shut off entirely? Given the hugely negative budget of fresh water, "sea level" in the Mediterranean Sea would drop rapidly, by as much as a kilometer in 2,000 years. Such a scenario would have seemed like science fiction until the Glomar Challenger's 1970 expedition.

At the first drill site, the Challenger's drill bit jammed on a very hard layer 200 meters below the bottom of the sea. The next day, Hsü and his co-lead scientist, William Ryan of Lamont-Doherty Earth Observatory, found out why. "It brought up buckets full of gravel," Ryan says.

Seafloors don't often contain beds of gravel, and when they do, it is usually continental rocks washed down from the adjacent land. But this gravel had marine fossils and rock, mixed with crystals of gypsum. Geologists call gypsum an "evaporite," because in the present-day world it forms in evaporating shallow bodies of water — as in the Dead Sea, for example. The implication was startling. "When Ken held up the gypsum crystals, he turned to me and asked, 'Do you think the Mediterranean dried out?'" Ryan remembers.

The same story was repeated at every stop. Ryan and Hsü found other evaporites like halite (sodium chloride, aka table salt). Oxygen isotopes in seashells embedded in the gravel suggested that these unlucky animals had lived in a brine from which 90 percent of the original water had evaporated. Hsü and Ryan also gathered evidence that the colliding of the African and Eurasian tectonic plates had lifted up the land on both ends of the Mediterranean Sea, closing its former connection with the Indian Ocean and narrowing the connection with the Atlantic Ocean.

The clinching piece of evidence came to light after the Challenger mission had ended. Other geologists discovered what appear to be buried ancient beds of several rivers that flow into the Mediterranean, particularly the Nile and the Rhône. It looked as if those rivers once emptied into the Mediterranean at least a kilometer below their present outlets — something that would be possible only if the sea level of the Mediterranean had been a kilometer [0.6 miles] below the global sea level at some point in the past.

In 1973, a meeting in Utrecht, Netherlands, established the desiccation model as the consensus theory. But a considerable amount of dissent has emerged in the last 20 years. "In the 1970s, the desiccation people won the debate," says Wout Krijgsman of Utrecht University, "but there are several aspects it cannot really explain."

Paradoxes galore

In part, the dissent reflects an improved understanding of what was occurring on Earth and in the area 6 million years ago. Since 1973, the story told by rocks, core samples and seismic soundings — and, increasingly, by computer simulations — has become more detailed and more dynamic, with changing shorelines, land bridges and volcanoes, and repeated episodes of climate change.

Also, there were fundamental problems with the desiccation hypothesis to begin with. Take the evaporites, for example: They do not have to form via evaporation, says sedimentologist and stratigrapher Vinicio Manzi of the University of Parma in Italy. They can also form by precipitation from a sufficiently concentrated brine. This can happen underwater, so there is no need to posit that the Mediterranean went bone dry.

And the buried riverbeds? Those, too, Manzi and his colleagues can explain: The sinking of briny water can produce downhill currents ("dense shelf water cascading," in geology lingo) sufficiently strong to scour out a canyon.

The idea of a single evaporation event also faces a mathematical problem: The existing salt deposit is too big to be explained by a single evaporation event. It represents about 5 percent of the salt in the world's oceans (and may have originally been 7 to 10 percent). To collect that much salt, the Mediterranean would have had to empty and refill about 10 times.

In fact, evidence from salt deposits in Sicily suggests something like that actually happened. There, gypsum beds alternate with shale beds that are rich in organic material and could have formed in periods when the gateway between the Atlantic and Mediterranean was open. There are 16 beds in all, with ages spaced about 23,000 years apart.

This periodicity is well known to geologists: It's the time it takes for Earth's axis (like a wobbly top) to trace one complete circle. And it correlates with changes in climate and ancient sea levels the world over. With the presumptive Gibraltar gateway being so shallow during this period, sea level fluctuations due to this "precessional cycle" could have repeatedly opened and closed the connection between the Mediterranean Sea and the Atlantic.

That period of gypsum formation is now called Stage 1 of the salinity crisis. Stage 2 was a relatively brief 50,000-year period when (in the majority opinion) the gateway slammed entirely shut, the sea level in the Mediterranean plummeted, and huge deposits of halite (sodium chloride) precipitated out from the seawater. However, Manzi's group strongly dissents, arguing that the Gibraltar gateway remained open, but shallowed to such an extent that the water flowed through it in one direction only — in but not out — resulting in a runaway buildup of salt.

Even for adherents of the majority view, Stage 2 is not as simple as it seems. Data from chlorine isotopes suggest that the drawdown was not uniform. At its lowest point, in the western Mediterranean, sea level was 800 meters below its present level, while east of present-day Sicily it was at least twice as deep as that. If so, the east and west portions must have been separated by a land bridge. Indeed, there is evidence of African animals crossing over to Europe during this time.

The last 200,000 years of the salinity crisis, called Stage 3, have been the most puzzling of all. The halite stopped precipitating and there is evidence for a variety of sea levels in the Mediterranean during this time. Widespread fossils of a shrimp-like animal called an ostracod suggest that the waters became much less salty, so that the Mediterranean was a sea-sized lake (and indeed, this stage is sometimes called the Lago-Mare stage). But if the gateway to the Atlantic was still closed, then where did the fresher water come from?

A 2025 paper by Daniel García-Castellanos of the Spanish National Research Council helps solve the puzzle. Using a computer to model erosion, he argues that the Mediterranean was gradually refilling during Stage 3. The ostracods provide a clue to the source. They originated from the area of the present-day Black and Caspian Seas, which back then were connected to each other, but not to the Mediterranean.

With the shores of the Mediterranean being so newly exposed and so steep, its edges would have rapidly eroded toward today’s Black Sea, which at that time was a much larger freshwater lake called the Paratethys. The first connection between them could have been established at this time. If so, the Mediterranean began to receive waters from rivers like the Volga, the Don and the Danube, which had previously been unavailable. The ostracods got a new home, and the Mediterranean got a vast new supply of water, which according to the computer simulation raised its surface to within 300 meters of its current level.

According Krijgsman, this interpretation conveniently reconciles the conflicting evidence. "In the fight between a desiccated and full Mediterranean," says Krijgsman, García-Castellanos' paper does the job "if you want to sit in the middle and give everyone credit for their observations."

Missing: One megaflood

The literature on the Messinian salinity crisis is voluminous, and yet one thing is curiously absent. There is surprisingly little direct evidence of the megaflood that supposedly ended the crisis. Hsü's original Scientific American article devotes only half a page to it and adduces little in the way of evidence. Fifty years later, Ryan wrote a 100-page retrospective; only three pages are about the megaflood. Shouldn't this extraordinary flood have left very clear scars?

The current evidence is ambiguous at best. Geologists have found submerged flood-like deposits off Malta — but that's a long way from Gibraltar, the putative source of the flood. Also, if the Atlantic drained into a nearly empty Mediterranean basin, then sea levels around the world should have dropped by about nine meters — an anti-flood to pay for the Mediterranean flood. There is no sign that this happened, says García-Castellanos.

A recent deep-sea drilling expedition to the Strait of Gibraltar turned up more questions than answers. In December 2023, the JOIDES Resolution — heir to the Glomar Challenger — revisited the Alboran Sea immediately to the east of the Strait of Gibraltar. If the strait is the door to the Mediterranean, then the Alboran Sea is the vestibule. Any megaflood that passed through the Strait of Gibraltar would have passed also through the Alboran basin. But Rachel Flecker of the University of Bristol, England, co-leader of the expedition, says they found no traces of the flood in the cores they collected.

While still on board the ship, she wrote that the cores were "exquisitely laminated in a variety of colors. This incredibly fine lamination requires very quiet, low energy conditions." Exactly the opposite of a megaflood. Final results have not been published yet, but Flecker reports also that they found no salt layer and no evidence that the salinity crisis had ever touched the Alboran Sea.

"The connection between the Atlantic and Mediterranean before and during the Messinian salinity crisis wasn’t through Gibraltar," she concludes.

How can this be? "A feature that you must take into account, and nearly nobody does, is that the present physiography of the Mediterranean is very different from the Messinian one," says Booth Rea. "Large basins have opened since, like the Tyrrhenian; other regions have emerged, like Sicily." One possibility, he suggested, is that the gateway was somewhere to the east, through a volcanic arc of islands that once connected Africa to the Balearic Islands. Other possibilities include channels through Spain or Morocco, which are above sea level now but were underwater as recently as 7 million years ago.

Regardless of how it happened, this modern view of the story holds lessons: It emphasizes the power not of dramatic events but of small changes. "Salt giants" — that is, massive salt deposits like the one underneath the Mediterranean — have formed at other times in Earth's history, when basins were trapped between two tectonic plates. Their effects on climate and biodiversity have likely been huge: In this event, 89 percent of exclusively Mediterranean marine species died out.

And a slight shallowing of the Strait of Gibraltar (or whatever the true gateway was) might be all that was needed to trigger these vast changes. "In some sense, this is more terrifying," says Manzi, because it shows that "you can reach extreme conditions without extreme events."

This article originally appeared in Knowable Magazine, a nonprofit publication dedicated to making scientific knowledge accessible to all. Sign up for Knowable Magazine’s newsletter.

The extreme cold from an incoming winter blast could make some trees "explode," a viral social media post claims — but don't expect trees to start blowing up like cars in an action movie.

"EXPLODING TREES are possible in the Midwest and Northern Plains on Friday and Saturday, as temperatures are forecasted to fall 20 degrees BELOW zero!" Max Velocity (real name, Max Schuster), a weather-based content creator with a degree in meteorology, wrote in a post on the social platform X.

The frigid temperatures stem from a wave of Arctic air that's heading south. The National Weather Service (NWS) has forecast "life-threatening cold" and the potential for wind chills as low as minus 50 degrees Fahrenheit (minus 46 degrees Celsius) across the Northern Plains. The agency has issued extreme-cold warnings for much of the Northern Plains and Upper Midwest.

But can extreme cold really make trees explode?

It depends on your definition of "explode." Trees can crack in frigid conditions due to their sap. This substance is usually liquid even in freezing temperatures, but when it gets super cold, like minus 20 F (minus 29 C), it freezes. In some places, the incoming Arctic blast will likely be cold enough to freeze trees' sap, causing it to quickly expand, Bill McNee, a forest health specialist at the Wisconsin Department of Natural Resources, told the Milwaukee Journal Sentinel.

"That just creates a lot of physical pressure that can lead to the frost cracking appearing suddenly, branches can fall off, and people hear this really loud crack from their tree, almost like it's a gunshot," McNee said.

The cracking usually affects only part of the tree, but in rare cases, explosions can happen, McNee said.

"I've never seen the damage of it, but from what I have seen and what I read online is that it is rare for there just to be so much pressure that is suddenly released inside this tree that it almost does explode," McNee said.

Meteorologist Cody Matz also addressed the explosion claim in an article for Minneapolis-based Fox 9, writing that "it can and does happen" but that it's "extremely rare." Matz noted that many people have likely lived in Minnesota and the Upper Midwest their whole lives without ever hearing of exploding trees.

The news nonprofit organization South Dakota News Watch, in partnership with the fact-checking nonprofit Gigafact, concluded that the claim that trees can explode during extreme cold was misleading but noted that temperature-driven breaking and snapping "can sound like an explosion."

Winter blast

Regardless of whether trees can "explode," some areas will have a chance to experience the rare cracking phenomenon. The NWS is forecasting temperatures below minus 20 F in parts of North Dakota, Minnesota and Wisconsin over the weekend, while the wind chills starting today (Jan. 22) will be even colder.

"This arctic blast will be accompanied by gusty winds, leading to dangerous wind chills," an NWS representative wrote in a Weather Prediction Center update Thursday. "The coldest wind chills may fall below -50 [F] across the Northern Plains with sub-zero wind chills reaching as far southeast as the Mid-Atlantic, Mid-Mississippi Valley and Southern Plains. These wind chills will pose life-threatening risk of hypothermia and frostbite to exposed skin."

The Arctic air is also set to fuel a massive and long-lasting winter storm, in conjunction with a surface front farther south and a midlevel disturbance passing through northern Mexico, according to the Weather Prediction Center update. AccuWeather reported that the winter storm is expected to bring heavy snow and ice down on more than 150 million people across 24 states from Friday through the weekend.

Meteorologists told The Associated Press that a stretching polar vortex is to blame for the Arctic blast. The polar vortex is an area of low pressure and cold air that circulates around the North and South poles all the time. Around the North Pole, the Arctic polar vortex is a circle of strong, cold winds that picks up every winter and sends cold air south with the jet stream when it's disrupted or stretched.

A warming Arctic, fueled by climate change, is energizing the polar vortex and helping to send cold air south, according to The Associated Press. Extreme winter weather is often linked to what the polar vortex is doing, although researchers are still deciphering all of the drivers behind the vortex's behavior.

This striking satellite photo shows rippling ribbons of ethereal ice swirling like turbulent clouds on the surface of Lake Michigan, alongside a snow-covered Chicago. The wintery scene occurred during an extreme cold snap triggered by changes to the polar vortex, experts say.

The greater Chicago region is home to around 9.5 million people and is near the southernmost end of Lake Michigan — the third-largest of the Great Lakes, which covers an area of around 22,300 square miles (57,750 square kilometers) across Illinois, Indiana, Wisconsin and Michigan.

Between Jan. 19 and Jan. 24, 2025, the Windy City and other parts of the eastern U.S. were hit by an unusual cold snap, partially triggered by a sudden expansion of the polar vortex — the persistent area of cold, low-pressure air circulating high in the stratosphere above the Arctic. During this time, temperatures in Chicago fell to as low as minus 33 degrees Fahrenheit (minus 36 degrees Celsius), according to the National Oceanic and Atmospheric Administration (NOAA).

This sudden drop in temperature, coupled with strong offshore winds, caused ice to form around the coastline and be pushed outward, creating the beautiful swirls. These flowing ribbons look a lot like clouds when viewed from above, but they are entirely ice, according to NASA's Earth Observatory.

In total, around 20% of Lake Michigan was covered by ice when the satellite photo was taken, which is just above average for the time of year, according to NOAA’s Great Lakes Environmental Research Laboratory (GLERL).

While lake ice is common in January, the extent of ice on Lake Michigan doesn't normally peak until February or March. It is also more common to see uniform sheets of ice rather than the flowing patterns visible in this image.

In this case, the darker, wispy ice near the lakeshore likely accumulated into thicker offshore constructs with rough edges that appear more white when viewed from above, Jia Wang, an ice climatologist at GLERL, told the Earth Observatory.

Other Great Lakes were also impacted by the cold snap, including Lake Erie, which saw up to 80% of its surface frozen, according to GLERL. Erie's ice was so thick and emerged so quickly that a Canadian cargo freighter was trapped in place for three days, according to the New York Times.

This is not the first time that satellite photos have revealed something unusual about Lake Michigan. In 2024, aerial images helped researchers identify more than 40 mysterious craters scattered across the lake's bed, which currently have no definitive explanation.

The low temperatures and strong winds around Chicago can also cause other unusual winter sights, such as bizarre chess piece-like sand sculptures along Lake Michigan's beaches, known as "hoodoos," which form when frozen chunks of sand are exposed to strong gusts.

For more incredible satellite photos and astronaut images, check out our Earth from space archives.

Caroline Muller looks at clouds differently than most people. Where others may see puffy marshmallows, wispy cotton candy or thunderous gray objects storming overhead, Muller sees fluids flowing through the sky. She visualizes how air rises and falls, warms and cools, and spirals and swirls to form clouds and create storms.

But the urgency with which Muller, a climate scientist at the Institute of Science and Technology Austria in Klosterneuburg, considers such atmospheric puzzles has surged in recent years. As our planet swelters with global warming, storms are becoming more intense, sometimes dumping two or even three times more rain than expected. Such was the case in Bahía Blanca, Argentina, in March 2025: Almost half the city’s yearly average rainfall fell in less than 12 hours, causing deadly floods.

Atmospheric scientists have long used computer simulations to track how the dynamics of air and moisture might produce varieties of storms. But existing models hadn’t fully explained the emergence of these fiercer storms. A roughly 200-year-old theory describes how warmer air holds more moisture than cooler air: an extra 7 percent for every degree Celsius of warming. But in models and weather observations, climate scientists have seen rainfall events far exceeding this expected increase. And those storms can lead to severe flooding when heavy rain falls on already saturated soils or follows humid heatwaves.

Clouds, and the way that they cluster, could help explain what’s going on.

A growing body of research, set in motion by Muller over a decade ago, is revealing several small-scale processes that climate models had previously overlooked. These processes influence how clouds form, congregate and persist in ways that may amplify heavy downpours and fuel larger, long-lasting storms. Clouds have an “internal life,” Muller says, “that can strengthen them or may help them stay alive longer.”

Other scientists need more convincing, because the computer simulations researchers use to study clouds reduce planet Earth to its simplest and smoothest form, retaining its essential physics but otherwise barely resembling the real world.

Now, though, a deeper understanding beckons. Higher-resolution global climate models can finally simulate clouds and the destructive storms they form on a planetary scale — giving scientists a more realistic picture. By better understanding clouds, researchers hope to improve their predictions of extreme rainfall, especially in the tropics where some of the most ferocious thunderstorms hit and where future rainfall projections are the most uncertain.

First clues to clumping clouds

All clouds form in moist, rising air. A mountain can propel air upwards; so, too, can a cold front. Clouds can also form through a process known as convection: the overturning of air in the atmosphere that starts when sunlight, warm land or balmy water heats air from below. As warm air rises, it cools, condensing the water vapor it carried upwards into raindrops. This condensation process also releases heat, which fuels churning storms.

But clouds remain one of the weakest links in climate models. That’s because the global climate models scientists use to simulate scenarios of future warming are far too coarse to capture the updrafts that give rise to clouds or to describe how they swirl in a storm — let alone to explain the microphysical processes controlling how much rain falls from them to Earth.

To try to resolve this problem, Muller and other like-minded scientists turned to simpler simulations of Earth’s climate that are able to model convection. In these artificial worlds, each the shape of a shallow box typically a few hundred kilometers across and tens of kilometers deep, the researchers tinkered with replica atmospheres to see if they could figure out how clouds behaved under different conditions.

Intriguingly, when researchers ran these models, the clouds spontaneously clumped together, even though the models had none of the features that usually push clouds together — no mountains, no wind, no Earthly spin or seasonal variations in sunlight. “Nobody knew why this was happening,” says Daniel Hernández Deckers, an atmospheric scientist at the National University of Colombia in Bogotá.

In 2012, Muller discovered a first clue: a process known as radiative cooling. The Sun’s heat that bounces off Earth’s surface radiates back into space, and where there are few clouds, more of that radiation escapes — cooling the air. The cool spots set up atmospheric flows that drive air toward cloudier regions — trapping more heat and forming more clouds. A follow-up study in 2018 showed that in these simulations, radiative cooling accelerated the formation of tropical cyclones. “That made us realize that to understand clouds, you have to look at the neighborhood as well — outside clouds,” Muller says.

Once scientists started looking not just outside clouds, but also underneath them and at their edges, they found other small-scale processes that help to explain why clouds flock together. The various processes, described by Muller and colleagues in the Annual Review of Fluid Mechanics, all bring or hold together pockets of warm, moist air so more clouds form in already-cloudy regions. These small-scale processes hadn’t been understood much before because they are often obscured by larger weather patterns.

Hernández Deckers has been studying one of the processes, called entrainment — the turbulent mixing of air at the edges of clouds. Most climate models represent clouds as a steady plume of rising air, but in reality “clouds are like a cauliflower,” he says. “You have a lot of turbulence, and you have these bubbles [of air] inside the clouds.” This mixing at the edges affects how clouds evolve and thunderstorms develop; it can weaken or strengthen storms in various ways, but, like radiative cooling, it encourages more clouds to form as a clump in regions that are already moist.

Such processes are likely to be most important in storms in Earth’s tropical regions, where there’s the most uncertainty about future rainfall. (That’s why Hernández Deckers, Muller and others tend to focus their studies there.) The tropics lack the cold fronts, jet streams and spiraling high- and low-pressure systems that dominate air flows at higher latitudes.

Supercharging heavy rains

There are other microscopic processes happening inside clouds that affect extreme rainfall, especially on shorter timescales. Moisture matters: Condensed droplets falling through moist, cloudy air don’t evaporate as much on their descent, so more water falls to the ground. Temperature matters too: When clouds form in warmer atmospheres, they produce less snow and more rain. Since raindrops fall faster than snowflakes, they evaporate less on their descent — producing, once again, more rain.

These factors also help explain why more rain can get squeezed from a cloud than the 7 percent rise per degree of warming predicted by the 200-year-old theory. “Essentially you get an extra kick … in our simulations, it was almost a doubling,” says Martin Singh, a climate scientist at Monash University in Melbourne, Australia.

Cloud clustering adds to this effect by holding warm, moist air together, so more rain droplets fall. One study by Muller and her collaborators found that clumping clouds intensify short-duration rainfall extremes by 30 to 70 percent, largely because raindrops evaporate less inside sodden clouds.

Other research, including a study led by Jiawei Bao, a postdoctoral researcher in Muller’s group, has likewise found that the microphysical processes going on inside clouds have a strong influence over fast, heavy downpours. These sudden downpours are intensifying much faster with climate change than protracted deluges, and often cause flash flooding.

The future of extreme rainfall

Scientists who study the clumping of clouds want to know how that behavior will change as the planet heats up — and what that will mean for incidences of heavy rainfall and flooding.

Some models suggest that clouds (and the convection that gives rise to them) will clump together more with global warming — and produce more rainfall extremes that often far exceed what theory predicts. But other simulations suggest that clouds will congregate less. “There seems to be still possibly a range of answers,” says Allison Wing, a climate scientist at Florida State University in Tallahassee who has compared various models.

Scientists are beginning to try to reconcile some of these inconsistencies using powerful types of computer simulations called global storm-resolving models. These can capture the fine structures of clouds, thunderstorms and cyclones while also simulating the global climate. They bring a 50-fold leap in realism beyond the global climate models scientists generally use — but demand 30,000 times more computational power.

Using one such model in a paper published in 2024, Bao, Muller and their collaborators found that clouds in the tropics congregated more as temperatures increased — leading to less frequent storms but ones that were larger, lasted longer and, over the course of a day, dumped more rain than expected from theory.

But that work relied on just one model and simulated conditions from around one future timepoint — the year 2070. Scientists need to run longer simulations using more storm-resolving models, Bao says, but very few research teams can afford to run them. They are so computationally intensive that they are typically run at large centralized hubs, and scientists occasionally host “hackathons” to crunch through and share data.

Researchers also need more real-world observations to get at some of the biggest unknowns about clouds. Although a flurry of recent studies using satellite data linked the clustering of clouds to heavier rainfall in the tropics, there are large data gaps in many tropical regions. This weakens climate projections and leaves many countries ill-prepared. In June of 2025, floods and landslides in Venezuela and Colombia swept away buildings and killed at least a dozen people, but scientists don’t know what factors worsened these storms because the data are so paltry. “Nobody really knows, still, what triggered this,” Hernández Deckers says.

New, granular data are on their way. Wing is analyzing rainfall measurements from a German research vessel that traversed the tropical Atlantic Ocean for six weeks in 2024. The ship’s radar mapped clusters of convection associated with the storms it passed through, so the work should help researchers see how clouds organize over vast tracts of the ocean.

And an even more global view is on the horizon. The European Space Agency plans to launch two satellites in 2029 that will measure, among other things, near-surface winds that ruffle Earth’s oceans and skim mountaintops. Perhaps, scientists hope, the data these satellites beam back will finally provide a better grasp of clumping clouds and the heaviest rains that fall from them.

Research and interviews for this article were partly supported through a journalism residency funded by the Institute of Science & Technology Austria (ISTA). ISTA had no input into the story.

This article originally appeared in Knowable Magazine, a nonprofit publication dedicated to making scientific knowledge accessible to all. Sign up for Knowable Magazine’s newsletter.

This striking satellite photo captured a rare spectacle earlier this year, when "one of the driest places on Earth" experienced a rare snowstorm. This freak event temporarily turned the barren, rocky landscape white — and briefly shut down one of the world's most powerful radio telescopes.

The Atacama Desert is a roughly 40,500-square-mile (105,000 square kilometer) non-polar desert, located within a 1,000-mile-long (1,600 km) strip of land nestled between the Pacific Ocean and the Andes mountains in northern Chile. It is the world's oldest non-polar desert, having remained semi-arid for at least 150 million years. And it is home to the sunniest spot on Earth, the Altiplano Plateau, which experiences sunlight levels equivalent to those on Venus.

The desert is also widely considered to be one of the driest places on Earth, alongside other hyperarid spots, such as Antarctica and the Sahara. Some areas currently experience as little as 0.002 inches (0.5 millimeters) of rain annually, according to Guinness World Records. Previous research has hinted that parts of the Atacama went nearly 400 years without any recorded rain, between 1570 and 1971.

On June 25, a rare snowstorm hit Atacama after a "cold-core cyclone" unexpectedly drifted down from the north, covering over half the desert with white powder, according to NASA's Earth Observatory.

The satellite photo above shows a section of the desert in the Chajnantor Plateau, which rises to around 16,000 feet (5,000 meters) above sea level. This area is home to the Atacama Large Millimeter/submillimeter Array (ALMA) observatory — an array of more than 50 radio dishes that scour the "Dark Universe." (ALMA itself is not visible in the aerial photo.)

This area is well-suited to astronomical research because it is remote, dry and well-elevated, which reduces interference and maximizes the amount of data telescopes like ALMA can collect. But when the snow settled over the observatory, it temporarily forced ALMA into "survival mode," meaning that the dishes were repositioned to stop them from accumulating snow, halting observations.

The icy dust may have also affected the Southern Astrophysical Research (SOAR) Telescope, located around 530 miles (850 km) southwest of ALMA, but to a lesser extent, according to Live Science's sister site Space.com. The newly constructed Vera C. Rubin Observatory is also located in Atacama, near the SOAR telescope, but was not affected by the storm.

The snow did not last long, and most of it had disappeared by July 16. In some places, the sunlight was so intense that the snow likely sublimated, or turned directly from solid to gas, before it melted, according to the Earth Observatory.

This is not the first time that snow has fallen in the Atacama. Similar events also occurred in 2011, 2013 and 2021.

The region has also experienced several intense bouts of rain in recent years. When this happens, it can trigger deadly mudflows. In March 2015, at least 31 people were killed after heavy rainfall triggered Atacama's largest ever flood, according to a 2016 study.

Rain can also cause desert flowers, which normally appear in spring, to unexpectedly bloom during winter months, creating fields of vibrant petals to sprout up around the desert. This most recently happened in 2024, after a surprise rain shower caught the plants off guard.

Precipitation is rare in the Atacama for two reasons. Firstly, it sits within the "rain shadow" of the Andes, which block clouds moving in from the east. And second, cold ocean currents off the region's western Pacific coastline prevent water from evaporating into the air over the desert. This makes Atacama inhospitable to most lifeforms, aside from hardy desert flowers and extreme microbes that live well below its dry surface.

However, the recent instances of extreme precipitation in the region could be a sign that human-caused climate change is making it more likely for snow and rain to fall there. If this continues, the Atacama may one day no longer be one of the driest places on Earth.

For more incredible satellite photos and astronaut images, check out our Earth from space archives.

Death Valley has held the record for the hottest air temperature ever measured near Earth's surface for 112 years, but now scientists are calling for the title to be rescinded.

According to U.S. Weather Bureau data, the air temperature at Greenland Ranch in Death Valley reached a scorching 134 degrees Fahrenheit (56.7 degrees Celsius) on July 10, 1913. This is still the highest air temperature on record, but its authenticity has been debated by meteorologists and climatologists, because — despite global warming — temperatures in the region have rarely reached 130 F (54.4 C) since 1913.

"I, along with many meteorologists and climatologists, have been quietly skeptical of the Death Valley world record our entire careers," Roy Spencer, a meteorologist and principal research scientist at the University of Alabama in Huntsville who recently led a study about Death Valley's world record status, told Live Science in an email.

For the study, Spencer and his colleagues analyzed July temperatures recorded at stations within 155 miles (250 kilometers) of Greenland Ranch between 1923 and 2024. The stations were 3,000 to 3,700 feet (910 to 1,130 meters) above sea level while Greenland Ranch is 178 feet (54 m) below sea level, so the researchers adjusted the data for elevation. (These were the closest stations to the ranch and provided the most reliable long-term data.) The team then compared the values and examined high-elevation July temperatures from 1913 to estimate the temperature at Greenland Ranch on that day.

They found that the air temperature at Greenland Ranch on July 10, 1913 was about 120 F (48.9 C), nowhere near 134 F. "The unusually hot temperatures measured at Greenland Ranch in early July 1913 are shown to be inconsistent with temperatures at surrounding stations," they wrote in the study, published Sept. 24 in the journal Bulletin of the American Meteorological Society.

Many scientists were previously skeptical about Death Valley's temperature record but few really questioned it because the World Meteorological Organization (WMO) accepted it and observations from the early 1900s with which to scrutinize the Greenland Ranch data were scarce, Spencer said.

"All deserts are hot in the summer, but Death Valley is especially hot because it is below sea level," he said. "The Death Valley record has more entertainment than climatological value, with an element of 'bragging rights' from the standpoint of tourism."

The U.S. Weather Bureau installed a station to measure temperatures at Greenland Ranch in 1911. The shelter was initially placed on the edge of an irrigated alfalfa field, but subsequent photographs suggest the ranch foreman, Oscar Denton, moved it to a hotter site above bare ground without official approval or documentation, according to the study.

Denton may have done this because ranch employees were used to measuring hotter temperatures on the ranch veranda than the station was recording and he wanted their experience to be reflected in the data, the researchers wrote. The veranda had a double roof, which may have vented hot air onto the veranda, they noted.

"While the station move away from the irrigated field would not explain the excessively hot temperature measurements, especially those in the first two weeks of July 1913, they support a pattern of straying from proper observing protocol," they wrote.

Denton may have also substituted some of the station's measurements for thermometer values on the veranda, Spencer said. "Newspaper, magazine, book accounts, and even correspondence with the Weather Bureau in San Francisco from back then show that 135 deg. F or hotter temperatures were made from that veranda using one or more thermometers of unknown provenance," he said.

The findings suggest Death Valley's world record should be rescinded, although temperatures of 130 F recorded in 2020 and 2021 might help the valley keep it, Spencer said. The period from July 2 to 18, 1913 and other years in the record also show anomalously high temperatures that should be scrutinized, the researchers noted in the study.

"I would support further investigation into this by the WMO and NOAA’s National Center for Environmental Information," said Dan McEvoy, an associate research professor of climatology at the Desert Research Institute who was not involved in the study.

The true story behind the value recorded on July 10, 1913 may never be known, but the study's conclusion that 134 F is incorrect is convincing and based on solid historical evidence, McEvoy told Live Science in an email.

"They are sampling from many surrounding stations, not just cherry picking one location," he said.

A striking new photo shows an eerie, UFO-like halo of red light seemingly hovering over a tiny town in the foothills of the Italian Alps.

The eye-catching image is remarkably reminiscent of another photo, taken in March 2023, which captured a near-identical red ring that briefly appeared over the same place.

Nature photographer Valter Binotto captured both of the rings over Possagno, a small town of around 2,200 people in northern Italy. The latest luminous halo was snapped on Nov. 17 at around 10:45 p.m. local time, and it appears to be slightly fainter than the one from two and a half years ago.

The red rings are actually examples of a rare lightning-related phenomenon dubbed "emission of light and very low-frequency perturbations due to electromagnetic pulse sources," or ELVEs, which occur during particularly intense thunderstorms, Spaceweather.com reported.

People rarely notice ELVEs because they are almost impossible to see with the naked eye. They flash in the sky for around one thousandth of a second, which is around 100 times quicker than it takes to blink. Therefore, photographers like Binotto either have to get really lucky or come equipped with special devices attached to their cameras to spot them.

ELVEs form when powerful lightning bolts shoot electromagnetic pulses (EMPs) up toward space, where they collide with the ionosphere — the ionized part of the upper atmosphere that stretches between 50 and 400 miles (80 and 644 kilometers) above the ground. Once there, they excite nitrogen molecules, which briefly give off red light, similar to how auroras form. (Although red auroras are the result of oxygen, not nitrogen.)

"The red ring marks the spot where the EMP hit Earth's ionosphere," Binotto told Spaceweather.com. In this case, the EMP was released by a lightning bolt with an electrical current of approximately 303 kilo-amperes, which is between 10 and 30 times higher than an average thunderstorm discharge, he added.

Given the rarity of ELVEs, which were discovered only in the 1990s from photos taken by NASA's space shuttles, you may be wondering what is so special about Possagno that causes these rings to appear there so often. And the answer is: nothing.

Instead, these photos are merely the result of Binotto's skill and experience in photographing ELVEs, and it is only a coincidence that he happened to take them both from the same place.

ELVEs are massive and appear high up in the atmosphere, meaning that they can be photographed from anywhere within a radius spanning hundreds of miles. In the latest photo, for example, the ELVE resulted from a thunderstorm near Vernazza, around 185 miles (300 km) south of Possagno. The 2023 ring was triggered by a storm near Ancona, around 174 miles (280 km) southeast of the northern town (see below).

The latest red halo likely spanned around 125 miles (200 km) across and appeared at an altitude of around 60 miles (100 km) above the ground, according to Spaceweather.com.

ELVEs, sprites and gigantic jets

ELVES are just one of several rare optical phenomena that are collectively known as transient luminous events (TLEs), which are all linked to specific types of lightning strikes.

Other TLEs include red "jellyfish" sprites, made of zig-zagging plasma tendrils that streak through the ionosphere, and upward-shooting "gigantic jets," which are towering blue-colored lights that can often be seen from space.

The electrical fields of ELVEs can also act as particle accelerators, creating X-rays, relativistic electrons and "terrestrial gamma ray flashes," according to the National Oceanic and Atmospheric Administration. These secondary effects pose no risk to people on the ground, but remain of great interest to scientists who can use them as a proxy for studying powerful cosmic rays.

However, it is unclear if the ELVES photographed by Binotto produced any of these effects.

This striking satellite image shows two near-perfectly parallel tornado tracks in Mississippi that were carved into the ground after a deadly storm system triggered more than 100 twisters across the U.S. in early 2025.

Between March 14 and 16, a series of extreme thunderstorms broke out in the High Plains and Midwest thanks to an "expansive upper-level trough" of warm, moist air. This storm system triggered 113 tornadoes across 14 U.S. states, according to The Weather Channel. At least 42 people are believed to have been killed, according to NBC News.

One of the worst-hit states was Mississippi, which experienced 18 tornadoes. Half of these reached at least Level 2 ("considerable damage") on the Enhanced Fujita scale (EF Scale), which measures the damage caused by a tornado. Around 1,000 houses were damaged in the state, according to the Mississippi Emergency Management Agency. Dozens of businesses and farms were also hit.

In this satellite image, you can see two different tracks that were carved out by two separate tornadoes just outside of Tylertown, Mississippi. The longer and wider track stretches up to 55 miles (89 kilometers), while the smaller track is only around 9 miles (15 km) long. It is unclear which one appeared first, or how much time passed between the respective twisters.

Related: See all the best images of Earth from space

The larger of the two tornadoes is believed to have reached Level 4 ("devastating damage") on the EF Scale, making it the single most powerful twister of the entire storm system, according to NASA's Earth Observatory. Its wind speed likely reached 170 mph (274 km/h), which is equivalent to a Category 5 hurricane.

Around 50 miles (80 km) northeast of Tylertown, aerial photographs revealed another pair of tornadoes had passed at right angles to one another, creating a large X-shape in a forested area of Covington County, according to the National Weather Service station at Jackson, Mississippi.

2025 has been one of the worst years for U.S. tornadoes in recent memory, partly due to the recent La Niña phenomenon, which altered the trajectory of the Pacific jet stream above North America, creating drier and warmer conditions in southern states, according to the National Oceananic and Atmospheric Administration (NOAA).

March was particularly extreme, with a record 299 twisters recorded during that month, according to the National Centers for Environmental Information. (For context, the entire U.S. normally only experiences around 80 twisters during March, on average.)

But even without La Niña, the frequency of tornadoes has been increasing over time due to rising sea surface temperatures off the Gulf coast — a direct result of human-caused climate change.

Like other types of extreme weather, such as wildfires, heatwaves and floods, climate change is also making tornadoes more powerful, costly and deadly. In 2023, for example, at least 26 people were killed by a single, nearly mile-wide "wedge tornado" that ripped through parts of Mississippi.

Additionally, tornadoes are now starting to impact places where they have not historically been seen before. Some researchers have previously suggested that "Tornado Alley" — the central region of the U.S. where tornadoes are traditionally most likely to occur, in states such as Texas, Oklahoma, Kansas, Iowa and Nebraska — could now be considered to be everything east of the Rockies.

Researchers at NASA's Langley Research Center are currently working on a way to better predict when tornadoes will form by analyzing cloud patterns in satellite photos. They hope that this could eventually warn people about an impending twister up to 10 minutes before it happens, potentially saving many lives, according to the Earth Observatory.

Broadly speaking, the farther you get from the equator, the colder the average temperatures are. It's a major reason why the North and South poles are some of the coldest places on Earth, while many of the hottest deserts are concentrated near the center of the planet.

But that logic doesn't apply to parts of Western Europe. For example, the average January high in London is 47 degrees Fahrenheit (8.3 degrees Celsius), but Calgary, Alberta, 4,400 miles (7,100 kilometers) west of London, has an average January high in the low 30s (less than 1 C). Both cities are at nearly the same latitude: London sits at 51.5 degrees, and Calgary is at a latitude of 51 degrees, meaning they are about an equal distance from the equator.

Those cities aren't alone. New York City and Madrid lie at roughly the same latitude, but Madrid's average high in January is about 50 F (10 C), compared with 40 F (4.4 C) in New York City. If you were to find yourself in Vienna, Austria, in mid-January, the average high would be about 37 F (2.8 C), but hop about 4,500 miles (7,200 km) west, and besides the difference in language and food, you would find yourself in Grand Forks, North Dakota, where the average January temperature sits at 17 F (minus 8.3 C).

Overall, the average January temperature for the contiguous United States in 2024 was about 32 F (0 C), but the average temperatures in a number of countries throughout Western Europe felt warmer: Germany averaged 35 F (1.5 C), the United Kingdom averaged almost 39 F (3.8 C) and Spain averaged 47 F (8.4 C) in January 2024.

So why do some Western European cities have milder winters than those in parts of North America if they share the same latitude?

A key reason is a system of ocean currents in the Atlantic brings heat from the tropics up toward Europe, said Ben Moat, head of open ocean physics at the National Oceanography Centre in the U.K.

"If you imagine a wood stove in your house, it draws cold air towards the heat. It rises and circulates," he told Live Science. "That's also what happens in most of the world's oceans."

That system is called the Atlantic Meridional Overturning Circulation (AMOC), a web of ocean currents that loop through the Atlantic Ocean. The AMOC works like a massive conveyor belt that moves 600 million cubic feet (17 million cubic meters) of water per second and 1.2 petawatts of heat, roughly the amount of heat put out by a million power plants running simultaneously, Moat estimates.

The massive amount of warm water rushing to the Northern Hemisphere also heats up the atmosphere. Prevailing winds known as the westerlies then blow from west to east and carry the warm ocean air in the atmosphere inland like a "fan-assisted heater," David Thornalley, a professor of ocean and climate science at University College London, told Live Science in an email. The westerlies are especially strong in the winter, which helps create the "nice warm winter climate of southwest England," he said, at least compared to the winter climate of places at similar latitudes in North America, like Calgary or Winnipeg.

The oceans, Gulf Stream and jet stream

The European continent is also warmer because it is relatively narrow and surrounded by water. Simply being next to an ocean makes a big difference, Thornalley said, "because water can store so much heat. It builds up and stores heat in the summer, which it then releases to the atmosphere in winter. … It is why places next to the ocean tend to have milder winters than in the middle of a continent."

That also helps explain why parts of Europe tend to have cooler summers — while the ocean is warmer than the air in the winter, in the summer the ocean is cooler, he said. Over the summer, the cooler water reduces the temperature of the surrounding atmosphere which the westerlies then blow inland.

Unfortunately for cities like New York and Boston in the Northeast U.S., being next to an ocean doesn't necessarily mean warmer winters. A major reason is because of the Gulf Stream, a part of the AMOC that brings warm water up the East Coast of the U.S. It forms atmospheric waves that draw cold air from the northern polar region and delivers frigid air to the Northeast — potentially accounting for 30% to 50% of the temperature difference across oceans — according to a 2011 study in the journal Nature.

Another band of wind has a big impact on North America's climate: the jet stream. Similar to the westerlies, the jet stream flows west to east, but the jet stream operates in the upper levels of the atmosphere, and when it flows downstream of the Rocky Mountains, it "has a tendency" to dip south and allow "cold air from polar latitudes" to spill over North America, Sybren Drijfhout, a professor of physical oceanography and climate physics at the University of Southampton in the U.K., told Live Science in an email.

The jet stream is generally stronger in the winter because the temperature difference across the stream is larger during winter months: "bringing Canadian air to the U.S." can therefore lead to larger drops in temperature and more extreme weather as a result.

But the temperate climate in much of Europe may not last forever, especially as extreme weather is only becoming more common with climate change. Peter Ditlevsen, physicist and professor at the Niels Bohr Institute at the University of Copenhagen, co-authored a 2023 paper warning that the AMOC — which is critical to regulating the global climate, not just Europe's — could collapse due to human-caused climate change between now and 2095, which is much earlier than previous predictions.

The climate in certain parts of Europe would look more like Alaska or northern Canada, Ditlevsen told Live Science. "There have been some studies saying that agriculture in Ireland and England would fall by, you know, 50%," he said. "Obviously, we hope that this is not going to happen."

Equator quiz: Can you name the 13 countries that sit on Earth's central line?

The Air Force has captured jaw-dropping footage from inside the eye of Hurricane Melissa, which has caused widespread devastation as it made landfall in Jamaica.

The 53rd Weather Reconnaissance Squadron, known as the "Hurricane Hunters," entered the hurricane on Monday morning (Oct. 27) to collect data for the National Hurricane Center, News18 reported.

The Hurricane Hunters were met with a gigantic wall of swirling clouds, videos on the social platform X show. The eye appears eerily calm in the videos and has an almost-enchanting quality to it, yet the storm will be anything but for people in its path. The Category 5 hurricane is expected to make landfall on the southern coastline of Jamaica on Tuesday (Oct. 28), where it will unleash catastrophic damage.

Caribbean weather forecasts have been extremely ominous for days. AccuWeather meteorologists have warned that the hurricane could trigger a humanitarian crisis, while the U.S. National Hurricane Center noted that the life-threatening storm is expected to bring "catastrophic flash flooding, landslides and destructive winds."

The World Meteorological Organization's tropical cyclone specialist, Anne-Claire Fontan, told a press briefing that Hurricane Melissa will be "the storm of the century" for Jamaica, according to Reuters. Jamaica hasn’t been hit by a hurricane since Category 1 Hurricane Sandy made landfall there in 2012, and the island has never taken a direct blow from a Category 5 storm before. The storm has already caused three fatalities on the island.

Near-record-warm Caribbean waters have fueled Melissa's strength as it has slowly closed in on Jamaica. The country's authorities have urged citizens to seek immediate shelter and said that many communities will not survive the storm, the Guardian reported.

The risk to life may be similar to 2019's Hurricane Dorian, which hit the Bahamas, and 1992's Hurricane Andrew, which hit the southeastern U.S and the Bahamas, AccuWeather reported. The official death toll for Hurricane Dorian was 74 people, with 282 more still missing, while Hurricane Andrew directly caused 65 deaths and was the most devastating hurricane in Florida's history.

Hurricane Melissa also threatens countries such as Haiti, the Dominican Republic and Cuba, with at least four storm-related deaths already reported across Haiti and the Dominican Republic.

Meteorologists categorize hurricanes from 1 to 5 based on their maximum sustained wind speeds — anything above Category 2 is considered a major hurricane. Hurricanes reach Category 5 status when they have sustained winds of at least 157 mph (252 km/h).

On Monday, Hurricane Melissa blew past this threshold when its wind speeds strengthened to 175 mph (282 km/h), establishing it as the strongest hurricane of 2025 and potentially the most intense hurricane ever recorded so late in the Atlantic hurricane season (which runs from the beginning of June to the end of November), AccuWeather reported.

More hurricanes are rapidly intensifying in the Atlantic as climate change causes atmospheric and sea temperature to soar. Since March 2023, average sea surface temperatures around the world have broken records, with warming waters adding extra energy to hurricanes as they grow.

After circling the central Caribbean Sea and remaining 'near stationary' this week, Tropical Storm Melissa is now about 160 miles (260 kilometers) southeast of Kingston, Jamaica, and drifting southeastward at 1 mph (1.6 km/h).

The storm's bafflingly slow advance, which is projected to stay below an average person's walking speed at around 2 mph (3.2 km/h) over the weekend, could be dire for several Caribbean islands, experts warn.

Tropical Storm Melissa will continue to lumber along a path somewhere between Jamaica and Haiti, with forecasters predicting a slow movement toward the northeast and north in the coming hours, and a westward drift from Saturday (Oct. 25) onward.

Melissa is expected to bring 8 to 14 inches (20 to 35 centimeters) of rain to parts of the Dominican Republic, Haiti and Jamaica through Sunday (Oct. 26) night, with locally higher amounts possible, according to an update from the National Hurricane Center (NHC) at 8 a.m. ET today (Oct. 24).

"Significant, life-threatening flash flooding and numerous landslides are expected in the southern Dominican Republic and eastern Jamaica, with catastrophic flash flooding and landslides anticipated in southern Haiti," representatives wrote. "Across northern Dominican Republic, northern Haiti, and western Jamaica, 3 to 5 inches [8 to 13 cm] of rain are expected through Sunday night. Flooding impacts may increase across western Jamaica next week."

Researchers expect the storm to intensify rapidly into a major Category 3 or above hurricane over the weekend, fueled by near-record-warm Caribbean waters, but the storm is likely to remain incredibly slow-moving, CNN reported.

Melissa is the 13th named storm of the 2025 Atlantic hurricane season. It's unclear exactly what has been stalling it, but a combination of strong upper-level winds and other dampening conditions across weather systems could be responsible, according to CNN. For instance, the lack of a cold front — a wedge of cold air that pushes warmer air up and causes it to release its energy, creating bad weather — might partially explain Melissa's crawling speed.

But Melissa's lagging pace is not as unusual now as it would have been just decades ago. Research indicates that tropical storms are getting slower, particularly as they approach land masses. A 2018 study, for example, found that tropical storms globally slowed by 10% between 1949 and 2016 — and James Kossin, the study's author, tentatively linked this to human-caused global warming.

"The magnitude of the slowdown varies substantially by region and by latitude, but is generally consistent with expected changes in atmospheric circulation forced by anthropogenic emissions," Kossin, an atmospheric scientist at the National Oceanic and Atmospheric Administration (NOAA) Center for Weather and Climate and at the University of Wisconsin-Madison, wrote in the study.

In a subsequent study published in 2019, Kossin and a colleague reported that North Atlantic tropical storms have become more likely to "stall" in coastal regions, bringing more rainfall to those areas. The researchers attributed this observation to both slower moving speeds and abrupt changes in direction, noting that tropical storms now spend many hours simply hovering, which is what Melissa is currently doing.

Their results are bolstered by more recent research in the journal PNAS, which revealed that the average duration of tropical cyclones has increased over the past 300 years. Additionally, a 2020 study found that future climate change will draw out tropical storms, particularly in the midlatitudes.

The problem with slow-moving tropical storms is that they can dump huge quantities of rain on certain areas, triggering devastating floods and mudslides. An example of this was Hurricane Harvey's "stall" over Texas in 2017, which caused the highest rainfall total from a tropical cyclone in U.S. history, according to CNN.

A Hurricane Watch is up for the south coast of Haiti and a Tropical Storm Watch for Jamaica as newly-formed Tropical Storm Melissa chugs west across the central Caribbean. Melissa is gathering strength over near-record-warm Caribbean waters untouched by any hurricane or tropical storm so far this year, and as of 2 p.m. EDT Tuesday, was located in the central Caribbean about 305 miles (490 kilometers) south of Port-au-Prince, Haiti. Melissa's top sustained winds were already 50 mph (85 km/hr), and the storm was predicted by the National Hurricane Center to reach hurricane strength by Saturday. Melissa was moving just north of due west at around 14 mph (22 km/hr).

The many possibilities for Melissa's future over the next few days include multiple days of torrential rain over some of the Caribbean's most flood-vulnerable places. Disastrous flooding and mudslides are an increasing threat for Haiti, as well as across the southern Dominican Republic. Because of high wind shear from the placement of the subtropical jet stream from Florida eastward through the Bahamas, Melissa is not expected to pose any threat to the continental United States for at least the next week, and ensemble models indicate only a remote chance that the storm could end up far enough northwest to affect Florida.

Melissa is the 13th named storm of the 2025 Atlantic season, forming just four days before the average arrival of the season's 13th named storm — October 25 (across the period 1991-2020).

Near-record-warm Caribbean waters will fuel Melissa's growth

Although we're near the tail end of the Atlantic hurricane season, the Caribbean is where you'd most expect to see a named storm develop in mid-to-late October, since wind shear farther to the north has typically become too strong for tropical cyclones. At this point in the year, the Caribbean's waters haven't usually cooled too much from their seasonal peak, while the wind shear that so often makes the Caribbean a "graveyard" for incipient tropical systems has typically lessened.

This week, Melissa will traverse some of the warmest waters ever recorded this late in the season anywhere in the Atlantic basin. Averaged across the Caribbean, sea surface temperature was at least 0.5 degree Celsius (0.9°F) warmer as of Sunday, October 19, than in any year on that date except 2023 and 2024, as analyzed by the University of Arizona's Kim Wood.

Human-caused climate change has made the current warmth in the central Caribbean an incredible 500 to 800 times more likely to occur, according to Climate Central's Climate Shift Index (see Fig. 2).

Where will Melissa head?

If Melissa were to follow the initial forecast from the National Hurricane Center issued at 11 a.m. EDT Tuesday, it would slow to a crawl just south of Haiti into the weekend (and perhaps beyond) while still gathering strength — a recipe for potentially devastating floods and mudslides over southern Hispaniola. Poverty, governmental instability, and deforestation have left Haiti extremely vulnerable to the kind of disaster Melissa could inflict.

That said, forecast models have been far from unanimous on Melissa's future (see Fig. 3 below). Part of the problem is that the storm lacked a well-defined center until Tuesday. Now that Melissa is a bona fide tropical storm, we may well see an increasing amount of model agreement. However, it appears steering currents will be weak, and slow-moving storms can be problematic for even the best forecast models.

Through early Tuesday, the European model continued to favor a slow westward track, with most of the European model ensemble members keeping the system in the Caribbean through at least next Monday, October 27 (left side of Fig. 3), though a substantial minority bring Melissa toward western Haiti. The GFS (American) model (right side of Fig. 3) has been just as insistent that Melissa will make a northward turn and leave the Caribbean, but its ensemble members differ starkly on the timing and location of that turn. The Google DeepMind AI-based model, which has been a top performer on track this year, also leans toward an eventual northward turn but again with sharp variations among ensemble members on its timing and location.

Intensity forecast for Melissa

Steady strengthening appears to be a safe bet for Melissa over the next several days. The storm is embedded in an uncommonly moist atmosphere: mid-level relative humidity will be climbing from 70-75 percent on Tuesday to as high as 80 percent by Wednesday. Wind shear was a moderate 10-20 knots on Tuesday afternoon, and is expected to remain moderate to high for a couple of days. High pressure at upper levels is predicted to build over the Caribbean toward this weekend, which would favor strengthening.

As well as unusually warm surface waters, the Caribbean has ample oceanic heat extending to a substantial depth right now, so even a slow-moving Melissa is unlikely to be greatly hindered by churning up cooler subsurface water. NHC was not predicting Melissa would rapidly intensify over the next five days, but the 18Z Tuesday SHIPS model forecast called for a 12% chance of rapid intensification of 35 mph in 24 hours, and a 25% for rapid intensification by 75 mph in 72 hours. That would put Melissa at category 3 strength on Friday afternoon, with 125 mph winds.

If the forecast scenario of an "M" storm in October cruising into the Caribbean, stalling, and turning north as a major hurricane seems familiar to you, it should: this outcome would be remarkably similar to what we saw with Matthew in 2016.bmcnoldy.blogspot.com/2025/10/meli...#Melissa

— @bmcnoldy.bsky.social (@bmcnoldy.bsky.social.bsky.social) 2025-10-23T12:03:13.447Z

The dangers of late-season hurricanes in the Caribbean

Slow-moving, late-season systems that gain strength in the Caribbean can cause immense trouble. In early October 2016, Hurricane Matthew moved north over far western Haiti as a Category 4 hurricane, dumping more than 20 inches (500 mm) of rain over much of far eastern Cuba and southwestern Haiti and pummeling the Bahamas and several other islands. Matthew took 731 lives and caused more than $16 billion in damage (2016 USD).

Just over 20 years ago, Hurricane Wilma strengthened with astonishing speed into a Category 5 monster in the northwest Caribbean. On October 18-19, 2005, Wilma set two all-time records for the Atlantic basin for rapid intensification, as the storm deepened from 975 to 892 millibars (hPa) in 12 hours and from 979 to 882 mb in 24 hours — the latter making Wilma the strongest hurricane by central pressure in Atlantic history. Wilma also set a record for the largest 24-hour increase in top sustained winds, going from 75 to 175 mph. Wilma struck Mexico's Yucatan Peninsula as a strong Cat 4 storm and raced northeast to strike southwest Florida on October 24 at Cat 3 strength. Wilma led to 52 deaths and caused $26.5 billion in damage (2005 USD).

Near the end of October 1998, former Category 5 Hurricane Mitch dumped mammoth amounts of rain over Guatemala, Nicaragua, and Honduras (30 to 40 inches, or 750-1000 millimeters, in many areas) even as it decelerated and weakened, coming onshore at Cat 1 strength. Flooding and landslides caused some $6 billion in damage (1998 USD) and caused more than 11,000 confirmed fatalities, with another 11,000 missing people unaccounted for. Mitch was the deadliest Atlantic hurricane of the satellite-monitoring era (i.e., since the 1960s), and perhaps since the Great Hurricane of 1780.

This article was originally published by Yale Climate Connections.

This year has seen some of the most destructive extreme weather events on record. Wildfires in Los Angeles were a big part of the equation, but several other events also left devastation in their wake. From winter storms in Louisiana to flash floods in Texas, here's a look at the wreckage from some of nature's most damaging events this year.

Related: Extreme weather caused more than $100 billion in damage by June — smashing US records

Wildfires sweep through Los Angeles

Wildfires swept through the Palisades and Altadena in Los Angeles in January, causing around $58 billion in damage.

Fires extinguished in the Palisades

The Palisades fires left 12 people dead after torching a vibrant coastal community.

Snow storms in New Orleans

Winter storms hit the South, including New Orleans, in January.

Tornadoes carve through Mississippi

In March, tornadoes ripped through Mississippi, leaving brutal scars that were spotted by the Landsat 8 satellite.

Destructive Kentucky floods

Violent rainfall in April hit several states, including Kentucky, leaving large areas underwater.

Tornado strike

Tornadoes also left a trail of devastation across Kentucky in May.

Everglades cracked and dry

In May, parts of Florida's Everglades were left cracked and desolate as the state suffered its worst drought since 2012.

Before and after the river burst

In July, devastating flash floods in Texas left at least 135 people dead. Maxar Technologies satellites captured the area before and after the Guadalupe River burst its banks.

Search and rescue operations

Monroe Canyon fire from space

This false-color image from NASA shows swathes of Monroe Canyon, Utah, burning in July.

Fires burn historic site

In September, lightning caused wildfires to burn through the historic Chinese Camp in California, a Gold Rush town established around 1850.

Two hurricanes could "dance" in the Atlantic this week as forecasters warn of life-threatening surf and rip currents along the East Coast. However, if the duo does dance, that could actually save the East Coast from the potentially catastrophic rainfall one of the storms would normally bring.

Tropical Storm Imelda is currently passing over the northwestern Bahamas and is expected to intensify into a hurricane on Tuesday (Sept. 30), according to the National Hurricane Center (NHC). Meanwhile, hundreds of miles offshore, Hurricane Humberto continues to rage after reaching Category 5 hurricane status on Saturday (Sept. 27).

The two storms could potentially swirl around each other in a hurricane "dance" called the Fujiwhara Effect, named after Japanese meteorologist Sakuhei Fujiwhara, Accuweather reported on Friday (Sept. 26). However, this rare weather phenomenon is complex and difficult for forecasters to model.

As things stand, Imelda is expected to move off the Bahamas and out to sea. Forecasters predict that the strength of Hurricane Humberto will drag Imelda east-northeast, so that it swings away from the East Coast, and toward Humberto.

"The rare Fujiwhara Effect between Humberto and Imedla is expected to help spare the southeast U.S. from widespread flooding rainfall," Alex DaSilva, the lead hurricane expert at AccuWeather, said in an emailed statement. "The influence from the much stronger and larger Humberto will tug at Imelda and help pull the storm away from the U.S. and out to sea."

Imelda is expected to contribute to heavy rain from Florida to North Carolina and southern Virginia, while both storms will likely generate dangerous rip currents from South Florida to the mid-Atlantic, the NHC has warned. Humberto will likely cause flash flooding in the northwestern Bahamas and eastern Cuba, with the potential for mudslides in Cuba, it reported.

Related: 'Now is the time': Hurricane category 6 could be introduced under new storm severity scale

The United Nations' World Meteorological Organization names tropical storms when they have maximum sustained wind speeds of more than 39 mph (63 km/h). Imelda crossed that threshold on Sunday (Sept. 28), and currently has maximum sustained wind speeds of 50 mph (85 km/h), according to the NHC.

To become a hurricane, Imelda's wind speeds will need to reach 74 mph (119 km/h) or greater, which is expected to happen on Tuesday. There are five categories of hurricane, measured against the Saffir-Simpson Wind Scale, based on the severity of the maximum sustained wind speeds.

Hurricane Humberto formed on Sept. 24 and continued to strengthen until it topped the hurricane scale at Category 5 on Saturday (Sept. 27), with maximum sustained winds of 160 mph (260 km/h). The hurricane is currently a Category 4 and is heading west with a similar strength and trajectory to Hurricane Erin, a previous Category 5 Atlantic hurricane that formed in August.

Hurricane Humberto and potential hurricane Imelda will come within 700 miles (1,100 kilometers) of each other during their closest pass, according to DaSilva. While the East Coast will still feel impacts from the storms, it could have been much worse.

"It's quite rare to see the Fujiwhara Effect in the Atlantic basin," DaSilva said. "The interaction between the two storms should prevent Imelda from making landfall or stalling near the coast, which could have led to days of torrential rainfall and widespread flooding. The impacts could have been catastrophic."

When two tropical storms meet during a Fujiwhara event, they don't simply bash into each other. The most likely Fujiwhara scenario is for one storm to get absorbed by the other. In this scenario, the storms could briefly rotate around each other before the smaller of the two gets sucked into, and becomes part of, the larger storm, Accuweather reported.

The Fujiwhara scenario can, on rare occasions, have an additive outcome, where the two hurricanes merge to become a more powerful single storm, according to the National Weather Service. Alternatively, two clashing storms can also just rotate around each other before spinning off in different directions.

China's southern megacities have entered emergency lockdown as they brace for the impact of a gigantic "super typhoon" predicted to make landfall on Wednesday (Sept. 24).

Super Typhoon Ragasa, the world's most powerful tropical cyclone this year, has already lashed Taiwan and the northern Philippines with torrential rain and destructive winds of up to 177 mph (285 km/h) — the equivalent of a strong Category 5 hurricane — leaving at least five people dead and dozens missing, according to officials.

Now, millions of people in Hong Kong, Macao and Shenzhen have been evacuated or urged to stay at home as the storm carves a path across China's south coast.

The typhoon is expected to make landfall in the country's Guangdong province Wednesday. So far, more than 770,000 people have been evacuated from Guangdong alone, with the number expected to rise to more than a million by the end of today (Sept. 23), according to the state-run broadcaster China Central Television.

"Ragasa will pose a serious threat to Hong Kong, which could reach the levels of Hato in 2017 and Mangkhut in 2018," Eric Chan, the city's chief secretary for administration, said Monday (Sept. 22), referring to two previous super typhoons that caused billions of dollars in damage. (A typhoon is considered a "super typhoon" if wind speeds reach 115 mph (185 km/h).

Hurricanes and typhoons are tropical storms that grow from a thin layer of ocean water that evaporates due to winds. That moisture rises to form storm clouds. The warmer the ocean is, the more energy the system gets, pushing the formation process into overdrive and enabling violent storms to rapidly take shape.

This is why storm season occurs from June to November and why the most powerful storms typically happen between August and September, when ocean temperatures peak.

Ragasa's extreme intensity has led to some claims that the storm is close to the upper limit of what Earth is capable of producing. There's some truth to this: Current calculations of the maximum potential intensity of storms peak at roughly 200 mph (322 km/h).

This estimate is made by a fairly straightforward formula that balances the kinetic energy of the storm lost to surface friction with the energy it extracts from warm ocean water.

Yet climate change is raising this bar, and scientists are discovering that it has already made extremely active hurricane seasons much more likely than they were in the 1980s. Since March 2023, average sea surface temperatures around the world have hit record-shattering highs, giving storms an extra shot of strength.

Thankfully, some of Ragasa's power will abate before the storm hits land. The typhoon is expected to weaken to the equivalent of a Category 3 hurricane, with wind speeds of roughly 115 mph (185 km/h), before making landfall between Shenzhen City and Xuwen county in Guangdong, according to China's National Meteorological Centre.

This striking satellite image highlights the aftermath of a major hailstorm in Alberta, Canada, which carved a giant "scar" in the landscape, around half as long as the Grand Canyon. The extreme event, which pelted the ground with golf ball-size ice chunks, killed at least two animals.

On Aug. 20, on what had otherwise been a calm day, a surprise storm began in a localized region of southern Alberta after the arrival of a "supercell" — a rare type of thunderstorm that contains a deep and persistent rotating updraft, according to NASA's Earth Observatory.

While the storm produced few lightning strikes, it triggered a serious hailstorm and high winds that caused widespread damage to houses, vehicles and infrastructure. Some of the hailstones reached a maximum diameter of 2 inches (5 centimeters), and the associated winds reached speeds of over 75 mph (120 km/h) — equivalent to a Category 1 hurricane, according to The Weather Network.

In addition to damaging property, the giant balls of falling ice hammered into the ground and tore up vegetation. The result was a roughly 125-mile-long (200 kilometer) and 9-mile-wide (15 km) scar etched across the landscape, which was clearly visible from space.

Related: See all the best images of Earth from space

The worst-affected area was around Brooks, a small city located around 100 miles (160 km) southeast of Calgary (visible in the top left of the satellite image). The combination of supersized hail and high winds damaged local houses and vehicles, as well as wrecking nearby power pylons, some of which were bent at a near 90-degree angle, Canadian news outlet CBC reported.

"The whole front of the house is destroyed," Brooks resident Colleen Foisy told CBC. "The front fence actually got ripped off of the cemented posts. My flowers in my garden got thrown around, branches from the trees. There's hail damage all over my truck that's only a year old. The cover to my boat got shredded."

The high winds also blew over a large fence at the White Barn Fun Farm, located west of Brooks, killing a Bactrian camel (Camelus bactrianus) and pony that were "best friends," the farm's owner told CBC. A horse and several birds were also injured.

"Hailstorm alley"

While this event was extreme, it is not unusual for such storms to appear in this part of Alberta, which is often dubbed "hailstorm alley."

"The region's climate and geography are conducive to storm development, and the area typically sees dozens of hail events each year," Earth Observatory representatives wrote.

Over the last five years, hailstorm damage in Alberta has totaled more than 6 billion Canadian dollars ($4.3 billion), excluding damages from August's storm, which are yet to be calculated, according to a recent report from Insurance Business magazine.

Some of the people affected by the most recent storm were still recovering from a similar event in July.

Researchers at NASA's Langley Research Center are now working on a way of being able to better predict these damaging storms in advance, to help mitigate their impacts.

"With state-of-the-art identification techniques, we can quantify severe storm distribution and frequency with an exceptional level of consistency that's only granted by satellite measurements," Benjamin Scarino, a research scientist at the center, told Earth Observatory. "Long-term satellite data records allow us to provide the reinsurance industry, project partners, and the research community with valuable insights into severe storm activity and risk."

A Category 4 hurricane in the eastern Pacific Ocean could hit Hawaii early next week, but it will weaken considerably before it gets there, storm predictions show.

Hurricane Kiko rapidly intensified from a tropical storm on Monday (Sept. 1) to a Category 4 hurricane on Wednesday (Sept. 3), according to The Weather Channel. The storm is moving westward and currently tracking across a region of warm water and low wind shear roughly 1,300 miles (2,100 kilometers) southeast of Hawaii, meaning it could strengthen in the next few hours, forecasters said.

The latest National Hurricane Center (NHC) forecast suggests Hurricane Kiko is heading for Hawaii and may reach the islands by Tuesday or Wednesday next week (Sept. 9 or 10). Kiko is whipping up winds of up to 145 mph (230 km/h), according to a CNN video — but meteorologists predict that these gusts will weaken over the weekend to the levels of a tropical storm or low-category hurricane.

Kiko is "yet another example of a hurricane undergoing rapid intensification amongst extremely warm waters," Brandon Miller, a senior meteorologist and supervising weather producer for CNN, said in the video. However, it's highly unlikely that the storm will remain as powerful as it is now through Sept. 9 or 10, Miller said, because it has to pass through a patch of relatively cold water and trade winds first.

Hurricane Kiko will likely hit the cool, windy patch on Sunday (Sept. 7), which will reduce some of the storm’s intensity, according to The Weather Channel. Pockets of dry air hovering to the east of Hawaii will further slow the storm and Kiko will also be forced to cross wind shear that will cut the ground from under its feet.

It's possible that Hurricane Kiko will miss Hawaii entirely, as the storm is expected to gain latitude through early next week. A "cone of uncertainty" shared by the NHC — which sums up the different paths that Hurricane Kiko might follow in the shape of an elongated, sideways teardrop — shows that Kiko's center track could move north of Hawaii, which would avert some of the storm's worst impacts on the archipelago.

Related: 'Now is the time': Hurricane category 6 could be introduced under new storm severity scale

But hurricanes don't have to make landfall to bring bad weather. "Don't let your guard down, Hawaiians," Miller said. "Kiko could still bring impacts to the island, such as flooding rainfall and gusty winds."

Swells caused by the storm could reach Hawaiian shores toward the end of the weekend, generating potentially life-threatening surf and rip currents, The Weather Channel warned. Many of the Hawaiian Islands also still sit within the NHC's uncertainty cone.

The distance between Kiko's center track and Hawaii's individual islands will determine how severe the impacts on those islands will be, according to The Weather Channel.

Residents should therefore check updates regularly and stay informed, forecasters said.

A new hurricane categorization system could help people better prepare for storms by incorporating risks from storm surges and rainfall into the categories, a study published this month reveals.

Storm surges — elevated seawater levels near coasts — and rainfall cause almost 80% of hurricane deaths, yet they are not accounted for in the Saffir-Simpson Hurricane Wind Scale (SSHWS), which forecasters currently use to categorize a hurricane's severity and plays a key role in communicating hurricane risk to the public. Some experts have previously argued that the threat of storms is not always properly reflected in the SSHWS's 1 to 5 category ratings, which are based solely on wind speed.

"There have been too many instances of incredible loss of life and destruction because a low category number on the SSHWS [...] did not match the danger of the storm," Jennifer Collins, a professor in the School of Geosciences at the University of South Florida and co-author of the new study, said in a statement.

The SSHWS estimates potential property damage from sustained wind, ranging from "some damage" in a Category 1 hurricane to "catastrophic damage" in a Category 4 or 5 storm. But property damage isn't the only potentially deadly effect of a hurricane. A low-category hurricane may still cause a tremendous tidal surge and unleash torrential rain, triggering devastating floods and other hazards.

One example is 2005's Hurricane Katrina, which was listed as a Category 3 based on wind speeds. But storm surge and rainfall were responsible for most of the 1,800 deaths caused by Katrina and contributed hugely to the $125 billion in damage, according to the new study.

Another example is Hurricane Florence, which made landfall in South Carolina in 2018 as a Category 1. The low danger rating did not alert communities to the catastrophic flooding that killed 55 people across the southeastern U.S., the researchers said.

Related: Birth of a hurricane: What meteorologists look for as they hunt for early signs of a tropical cyclone forming

"Frequently, people use the storm's category to decide whether to evacuate," Collins said. "That's incredibly dangerous because if they hear it's only a tropical storm or Category 1, too often no alarm bells go off, and they see no cause for concern."

To address the SSHWS's shortcomings, Collins and colleagues developed an alternative hurricane warning system in 2021. Dubbed the Tropical Cyclone Severity Scale (TCSS), this system has six categories and takes into account wind speed, storm surge and rainfall — the three biggest hazards from hurricanes.

The TCSS assigns scores between 1 and 5 to each of the three hazards depending on their predicted severity for a given hurricane. These scores are then combined into a final score, which is established using three rules in different scenarios.

First, the final score is never lower than the highest of the three individual hazard scores. Second, if two individual hazards have the same scores of 3 or higher, then the final score increases by one — so, if storm surge has a score of 2 but wind and rainfall are both 3, then the hurricane is classed as a Category 4. The third rule is that a final score of 6 is given if either two hazards have scores of 5, or if two hazards have scores of 4 and the third is a 5.

"The higher category is important," Collins said. "Many people base their decision to evacuate on that number, not just the details of the hazard."

A "more realistic" system

Researchers have been working on the TCSS for several years, but the new study looked to confirm its effectiveness at warning the public of a hurricane's dangers. To test their warning system, Collins and her colleagues sent 4,000 participants living along the Gulf and East coasts forecasts for 10 fictitious hurricanes affecting their communities.

Half of the participants received warnings in the SSHWS format, while the other half received warnings using the TCSS system. They then completed an online quiz about how they would react in the different scenarios. The team’s findings were published Aug. 19 in the journal Scientific Reports.

Participants who were sent TCSS forecasts were more likely to identify the main hazard from a hurricane correctly, and significantly more likely to evacuate for non-wind hazards than those who were sent SSHWS forecasts, according to the study.

Correct identification of the main hazard boosted participants' intent to take relevant precautions, such as shielding their houses against flooding with sandbags and erecting window protections against the wind. On the other hand, participants who had incomplete information about a storm were more likely to miscalculate risks or take no measures at all.

The results suggest that shifting away from the SSHWS would improve the public's understanding of hurricane risks and lead to more informed decision-making ahead of storms, Collins said.

"I'm fairly optimistic that now is the time," she said. "We now know many people make decisions based on the category messaging, so we need to ensure that we are communicating with a scale which is more realistic of the severity of the hurricane."

La Niña conditions could develop in the fall and early winter, but they will probably be weak and short-lived, forecasters say.

La Niña is the cold phase of the El Niño-Southern Oscillation (ENSO), a natural climate pattern of atmospheric and sea temperature changes in the tropical Pacific Ocean. During La Niña, the jet stream shifts northward, bringing wetter conditions and cooler winters to the northern U.S., while the southern U.S. experiences drier conditions and warmer winters. A La Niña also tends to ramp up hurricane activity over the Atlantic.

Conditions for this phase briefly developed last winter, but they didn't stick around long enough to be considered an official La Niña event in the historical record. The latest ENSO forecast from the National Weather Service indicated that we could be in for something similar in the coming months.

A period of La Niña conditions is favored for the fall and early winter, and there's a 21% chance that the current July-to-September period will qualify. The likelihood then rises to more than 50% for overlapping 3-month periods between September and January. Still, forecasters aren't expecting massive weather shifts.

"If La Niña forms, it's likely to be weak, meaning La Niña wouldn't exert a strong influence over the winter," Emily Becker, a research professor at the University of Miami and lead writer of the National Oceanic and Atmospheric Administration's ENSO blog, told Live Science in an email.

Related: Watch Hurricane Erin reach Category 5 strength in a blaze of lightning

The ENSO cycle triggers a warm El Niño phase and then a cold La Niña phase every two to seven years, on average, with each phase lasting around nine to 12 months. However, the timing of these phases varies, and they're difficult to predict.

The phases are defined by changes in the sea surface temperature of the Niño region of the east-central Pacific and a shift in atmospheric conditions, which impact the Pacific jet stream. El Niño conditions occur when the sea surface temperature is 0.9 degrees Fahrenheit (0.5 degrees Celsius) higher than the long-term average, while La Niña conditions happen when the sea surface temperature falls 0.9 F below the long-term average.

We were due to enter a La Niña last summer, but the conditions didn't develop until December. That delayed start meant that La Niña didn't have time to gain strength before the onset of winter.

Last year's warmer-than-average ocean temperatures might have played a role in the delay. Earth was in an El Niño between May 2023 and March 2024, which contributed to record-breaking heat during that period. However, the planet has continued to warm with climate change, regardless of what ENSO is doing.

Last winter's La Niña spell didn't make it into the record books because the temperature didn't remain below the 0.9 F threshold for at least five consecutive overlapping seasons — periods of three months. The latest data suggest that La Niña conditions are more likely than not in just three of these upcoming periods across the fall and winter, and thus any spell is unlikely to be an official La Niña.

"It's very possible we'll end up with another winter like 2024-25, with a few months of La Niña conditions, not quite enough to qualify as a La Niña event in our historic record," Becker said. "However, last winter's impacts ended up looking like those we'd expect during a moderately strong La Niña."

A weather satellite has captured stunning footage of Hurricane Erin crackling with flashes of lightning as it rapidly intensified into a Category 5 hurricane over the weekend.

The National Oceanic and Atmospheric Administration's (NOAA) latest geostationary satellite, GOES-19, recorded Erin as it strengthened into a hurricane on Friday (Aug. 15) and then topped the Saffir-Simpson Wind Scale with maximum sustained winds of 160 mph (260 km/h) on Saturday (Aug. 16).

Erin strengthened so quickly that it became one of the fastest intensifying storms in Atlantic history, CNN Weather reported. The tropical storm has varied in strength since becoming a Category 5, and is currently a Category 4, with maximum sustained wind speeds of about 130 mph (215 km/h).

While Erin isn't set to make landfall, it will likely threaten coastlines with life-threatening waves and flooding as it travels between the Bahamas and U.S. East Coast this week. A tropical storm warning is also currently in effect for the Turks and Caicos Islands and southeastern Bahamas, according to a National Hurricane Center (NHC) update.

The satellite images reveal stormy activity inside Erin, with lightning flashing around the eye of the storm like a bright blue iris.

Related: Hurricane Milton: Jaw-dropping images taken from space show the storm rapidly intensifying as it approaches Florida

The Geostationary Operational Environmental Satellites (GOES) are a network of satellites built by NASA and operated by NOAA. Researchers use the satellites for monitoring the weather on Earth and in space in real time.

Erin developed into a named tropical storm on Aug. 11 with winds of about 45 mph (75 km/h) — the United Nations' World Meteorological Organization names tropical storms with maximum sustained wind speeds of more than 39 mph (63 km/h). By Aug. 15, Erin was strong enough to be classified as a hurricane, breaching the threshold of sustained wind speeds of 74 mph (119 km/h) or greater, and continued to strengthen until it peaked as a Category 5 hurricane on Saturday.

Hurricanes are rapidly intensifying more frequently as atmospheric and sea temperatures rise with climate change. Researchers have documented record-breaking average sea surface temperatures in recent years, and the warming waters provide extra energy to growing hurricanes.

Erin is expected to vary in strength, but will continue to be a major and dangerous hurricane through the middle of this week, according to the NHC.

Coastal flooding and life-threatening rip currents are expected as Hurricane Erin barrels towards the East Coast this week, and the powerful storm has the potential to unleash 100-foot (30 meter) waves, forecasters warn.

Hurricane Erin emerged as the first hurricane of the 2025 Atlantic season over the weekend, rapidly intensifying on Saturday (Aug. 16) to become a Category 5, the strongest type of hurricane on the Saffir-Simpson Wind Scale. Erin then weakened and strengthened again and, at the time of writing, is a Category 4 with sustained wind speeds of about 130 mph (215 km/h).

The tropical storm is located just east of the southeastern Bahamas and is expected to travel between Bermuda and the East Coast by the middle of the week, according to a National Hurricane Center (NHC) update, published Monday (Aug. 18). While Erin isn't set to make landfall, it will likely threaten coastlines with dangerous waves and flooding.

On Sunday (Aug. 17), the National Weather Service issued a coastal flood watch for the East Coast, with flooding forecast as early as Tuesday (Aug. 19). The Outer Banks islands off North Carolina are expected to be especially vulnerable. Dare County, which includes a large section of the Outer Banks, issued a state of emergency on Sunday with a mandatory evacuation order for Hatteras Island in anticipation of the flooding.

And the buzzsawing-passage of the storm could give extra energy to wind-driven waves, giving them enough energy to reach enormous heights.

"The latest forecast does indeed indicate that the largest significant wave height could reach values in excess of 50 feet with an associated most likely largest wave of more than 100 feet," Jean Bidlot, an ocean and earth system modeling scientist at the European Centre for Medium-Range Weather Forecasts, told Newsweek.

The NHC also warned that the hurricane will lead to dangerous ocean conditions affecting the Bahamas, Bermuda, East Coast and Atlantic Canada over the next several days. "These rough ocean conditions will likely cause life-threatening surf and rip currents," representatives wrote in the update.

Related: Here's why storm surge during hurricanes can be so catastrophic

A hurricane is a type of tropical cyclone, or a rapidly rotating storm that forms over tropical oceans. For a tropical cyclone to be classed as a hurricane, it must generate maximum sustained wind speeds of 74 mph (119 km/h) or greater, according to NOAA. There are then an additional five categories of hurricanes, defined by increasing wind speeds from the 74 mph hurricane threshold (Category 1), all the way up to 157 mph (252 km/h) or higher (Category 5).

Hurricane Erin raced up the hurricane categories, from a Category 1 on Friday (Aug. 15) to a Category 5 on Saturday, making it one of the fastest intensifying storms in the history of the Atlantic, CNN Weather reported. The storm then weakend to a Category 3 on Sunday (Aug. 17), before picking up steam once more.

More hurricanes are rapidly-intensifying in the Atlantic as climate change causes atmospheric and sea temperature to soar. Since March 2023, average sea surface temperatures around the world have broken records, with warming waters adding extra energy to hurricanes as they grow.

As a Category 4, Erin is considered a major hurricane with sustained wind speeds of 130 to 156 mph (209 to 251 km/h) that would cause "catastrophic damage" to property, if there were any in its path. The hurricane also covers a large area, with its strong winds extending outward about 230 miles (370 km) and upwards about 80 miles (130 km), according to the NHC update.

Forecasters expect the hurricane to strengthen again on Monday, before experiencing some weakening overnight. However, regardless of this variation, Erin will continue to be a major hurricane that poses significant risks.

"Even though some weakening is forecast beginning tonight, Erin will remain a large and dangerous major hurricane through the middle of this week," NHC representatives wrote.

Satellite images reveal the scope of destruction in the south of France caused by the worst wildfire to hit the country in over seven decades.

The fire was first detected on Aug. 5, near the town of Ribaute in the Aude region in the southeast of France. Within less than four days, it turned some 42,000 acres (17,000 hectares) of forests and agricultural land into ashes  — an area larger than France's capital Paris.

The scope of the fire was captured in dramatic images taken by the high-resolution Pleiades Neo satellites operated by the European aerospace giant Airbus.

At its peak strength, the blaze was devouring about 2,470 acres (1,000 hectares) of land per hour, fanned by strong winds blowing from the Mediterranean Sea. Within two days of its ignition, the fire devoured 40,000 acres (16,000 hectares). At least one person died, and 13 others were injured as the fire engulfed several villages in the wine-making region, according to the BBC.

The Pleiades Neo images, taken the day after the fire started, reveal swaths of scorched land as well as burning hotspots and thick plumes of smoke covering the land. In some images, firefighting planes flying over the affected region can be seen.

NASA's Terra and Landsat 9 satellites also spotted the fire, revealing its fast-paced progress. The Terra image, obtained with the Moderate Resolution Images Spectroradiometer (MODIS), shows the situation in natural colors at 11:20 a.m. local time on Aug. 6.

The false-color images from Landsat 9, obtained one hour later, are a combination of shortwave infrared, near infrared and optical wavelengths, which together allow it to reveal the freshly burned ground that would otherwise be obscured by a thick layer of smoke.

Firefighters mostly contained the wildfire by Thursday evening, Aug. 7, according to Al Jazeera, but local authorities said it would take days to completely extinguish the remaining burning spots.

France's officials attributed the fire, the worst to have hit the country since 1949, to worsening climate change. France's popular Mediterranean coast has been hit particularly hard this year, registering over 9,000 wildfire breakouts since the beginning of the summer season, according to Al Jazeera.

The summer of 2025 is shaping up as one of the hottest on record in western Europe, with temperature records having been broken in the month of June, according to the E.U. environmental service Copernicus.

This striking satellite photo shows 10 swirling "dark voids" that appeared above an uninhabited volcanic island in the Indian Ocean. The black spots are the result of atmospheric cloud vortices, but are oddly pronounced and significantly contorted compared to most other examples of this phenomenon.

The spinning voids are trailing off Heard Island — an uninhabited Australian territory in the southern Indian Ocean, around 900 miles (1,500 kilometers) north of Antarctica. The cloud-obscured landmass has a surface area of around 142 square miles (368 square kilometers).

On average, the dark spots are around 8 miles (13 km) wide, decreasing slightly in size the further they have traveled, according to NASA's Earth Observatory. They are initially moving away from the island in a northeasterly direction (left to right).

The spinning holes are the result of a phenomenon known as von Kármán vortices, which occur when a prevailing wind encounters a landmass, disturbing the airflow and creating "a double row of vortices which alternate their direction of rotation," according to the National Oceanic and Atmospheric Administration. They are named for Theodore von Kármán, a Hungarian-American physicist, who was the first to describe this natural phenomenon.

In this case, the vortices are being created by Mawson Peak, a 9,000-foot-tall (2,700 meters) active volcano sat at the heart of Heard Island.

Related: See all the best images of Earth from space

Normally, von Kármán vortices create long trails of swirling clouds that get caught up in the disrupted air flows. The cloud streams are normally perfectly straight, such as a series of parallel vortex streams that emerged side-by-side off the Atlantic coast of Africa in 2015 (see above).

But in this case, the vortex stream appears to bend almost 90 degrees midway through the stream. This change in direction was most likely caused by a sporadic burst of the intense westerly winds that frequently blow across the area around Heard Island at speeds over 50 mph (80km/h), known as the "Furious Fifties," according to the Earth Observatory.

In most examples of von Kármán vortices, the resulting cloud trails can be quite wispy, tracing out the subtle variations in the invisible air currents, such as examples observed over Mexico's Guadalupe Island in 2012 and above Svalbard's Bear Island in 2023.

However, in this photo, the wispy trails are replaced by a string of concentrated holes, or gaps, within the clouds. This is probably due to exceptionally thick cloud coverage, which can be disrupted only at the heart of each spinning section within the vortex stream.

Mawson Peak is smaller than most of the peaks that regularly produce von Kármán vortices, making it slightly rarer for the cloud swirls to emerge there. However, Heard Island has produced more traditional vortex streams in the past, such as one showing in November 2015.

Space weather experts warn that a moderate-strength geomagnetic storm could hit Earth Friday or Saturday (Aug. 8 or 9) — possibly bringing auroras to northern U.S. skies.

On Wednesday (Aug. 6), the National Oceanic and Atmospheric Administration (NOAA) issued a geomagnetic storm watch and suggested that the storm is likely associated with a recent solar flare that erupted from an active region of the sun.

The effects of such a storm would be manageable and would be limited to technology infrastructure, NOAA said. But as a bonus for skywatchers, auroras may be visible from New York to Idaho.

Geomagnetic storms are temporary disturbances in Earth's magnetosphere that stem from solar wind entering nearby space. Long, high-speed winds traveling in the direction opposite to Earth's magnetic field often cause the most notable storms.

The largest geomagnetic storms are associated with coronal mass ejections (CMEs) — expulsions of billions of tons of plasma from the sun. The plasma and the magnetic field embedded in it usually reach Earth several days after erupting from the sun. The possible upcoming storm is predicted based on a CME that occurred on Aug. 5 after a solar flare.

The warning predicts that the storm will peak as a moderate category G2 storm on NOAA's five-tier scale for evaluating the severity of geomagnetic storms. (Category G5 storms are the strongest, like the one that struck Earth in May 2024 and made auroras visible as far south as Florida.)

Related: Scientists discover strong, unexpected link between Earth's magnetic field and oxygen levels

An onslaught of solar wind can cause changes in the currents, plasma and fields of Earth's magnetosphere, causing energetic particles to collect in the ionosphere — the part of the atmosphere that acts as a boundary between Earth and the vacuum of space. The extra heat and density in the ionosphere can apply drag on satellites in low Earth orbit and affect radio signals, which can disrupt navigation systems that rely on GPS.

Geomagnetic storms also often produce observable auroras at unusually low latitudes. Eighteen states, as far south as South Dakota and Iowa, may have a chance to witness the northern lights tomorrow and Saturday, NOAA predicts.

It's difficult for experts to guess exactly when the northern lights will show, but the agency suggests that the "best" auroras are typically visible in the dark, within one or two hours of midnight. The full Sturgeon Moon, which rises Aug. 9 at sunset, may outshine fainter auroras — so try to stand with your back to the moon if you go aurora hunting this weekend.

A lightning bolt that spanned five states in the Great Plains has set a new record for the longest lightning bolt ever recorded, the World Meteorological Organization has confirmed.

The "megaflash" zipped across 515 miles (829 kilometers) from eastern Texas through Oklahoma, Arkansas, Kansas to near Kansas City, Missouri, in seven seconds, beating the previous record of 477 miles (768 km).

The flash occurred on Oct. 22, 2017, but it was too long to be fully measured by ground-based sensors at the time. Now, a new study that used data from a geostationary satellite has finally documented the massive scope of the bolt. The researchers published their findings Thursday (July 31) in the Bulletin of the American Meteorological Society.

"It is likely that even greater extremes still exist, and that we will be able to observe them as additional high-quality lightning measurements accumulate over time," study senior author Randall Cerveny, a professor of geographical sciences at Arizona State University, said in a statement.

Exactly how lightning gets its initial spark is still contested. But scientists know it arises when electrons pool in one region of a storm cloud, thus creating an ionized path in the air between which the electrons can flow from regions of negative to positive charge.

In some storm clouds, particularly the huge clusters that form over hotspots such as the Great Plains, understudied dynamics within the clouds can lead to discharges that stretch beyond 60 miles (100 km) — earning them the title of "megaflashes."

Related: Lightning on Earth is sparked by a powerful chain reaction from outer space, simulations show

In the study, the scientists reconstructed the flash's length by analyzing data from the National Oceanic and Atmospheric Administration's GOES-16 satellite — one of four of the agency's satellites with mappers that continuously monitor the ground for zaps of lightning. Using new algorithms, the scientists separated the bolt from millions of other light flashes to reveal its full extent.

"Our weather satellites carry very exacting lightning detection equipment that we can use to document the millisecond when a lightning flash starts and how far it travels," Cerveny said.

Experts say that, beyond highlighting the impressive advancements in new weather-monitoring technologies, the discovery is an important reminder that lightning can strike far from the storm cells where it was initially generated.

"It illustrates the threat of the newly recognized 'bolt from the gray,'" analogous to the 'bolt from the blue' from isolated cells, but one that can travel many hundreds of kilometers from the main charge generating region," co-author Walt Lyons, president of FMA Research, a forensic meteorology investigation firm in Fort Collins, Colorado, said in a statement.

"If lightning is within 10 km [6.2 miles] as found with reliable lightning data, go to the lightning safe building or vehicle," he added. "As these extreme cases show, lightning can arrive within seconds over a long distance, but they are embedded within larger thunderstorms, so be aware."

A wildfire has ignited the North Rim of the Grand Canyon, burning down the Grand Canyon Lodge and other historic cabins.

Firefighters were managing the Dragon Bravo Fire, started by a lightning strike, when an uncommonly strong gust of wind pushed the fire beyond multiple containment features on Friday (July 11), according to InciWeb, the U.S. government's incident information management system website.

The fire then exhibited "extreme and volatile" behavior on Saturday (July 12), expanding by 500 acres (0.8 square miles) according to a statement released by the National Park Service (NPS). Conditions in the region are hot, dry and windy, making it more challenging for firefighters.

A second wildfire, named the White Sage Fire, is burning around 35 miles (56 kilometers) north of the Dragon Bravo Fire in Kaibab National Forest.

"Preliminary assessments indicate that between 50 to 80 structures have been lost, including NPS administrative buildings and visitor facilities," NPS representatives wrote in the statement. "No injuries or loss of life have been reported, and all staff and residents were successfully evacuated prior to the fire’s escalation."

Related: 'We are creating the fire equivalent of an ice age': Humans have plunged Earth into the 'Pyrocene'

Most wildfires are started by humans, either accidentally or on purpose, but lightning is a common natural cause, responsible for around 10% of global forest fires. Lightning can be as hot as 54,000 degrees Fahrenheit (30,000 degrees Celsius) — five times hotter than the surface of the sun — and pack as much as 5 gigajoules of energy. These sparks of electricity are more than capable of igniting dry vegetation and can set multiple trees alight in an instant.

The Dragon Bravo Fire began on July 4 and was initially managed as part of a confine and contain strategy. However, the fire has been growing at night, when visibility is reduced and firefighters can't use aerial resources to drop fire retardant and water on the fire, according to InciWeb.

The fires also damaged a nearby water treatment facility, which released toxic chlorine gas. The gas leak meant firefighters had to evacuate from critical zones near the fire, according to the NPS statement.

The Dragon Bravo Fire has currently burned around 5,000 acres (7.8 sq/m) of land, while the larger White Sage Fire currently covers around 50,000 acres (78 sq/m), according to the wildfire live tracking non-profit Watch Duty. Both were active at the time of writing, with strong winds, hot temperatures and low humidity driving them, NPS representatives wrote.

"With continued active fire behavior and ongoing risks to personnel and infrastructure, the North Rim will remain closed to all visitor access for the remainder of the 2025 season," NPS representatives wrote.

Flash floods like the one that swept down the Guadalupe River in Texas on July 4, 2025, can be highly unpredictable. While there are sophisticated flood prediction models and different types of warning systems in some places, effective flood protection requires extensive preparedness and awareness.

It also requires an understanding of how people receive, interpret and act on risk information and warnings. Technology can be part of the solution, but ultimately people are the critical element in any response.

As researchers who study emergency communications, we have found that simply providing people with technical information and data is often not enough to effectively communicate the danger and prompt them to act.

The human element

One of us, Keri Stephens, has led teams studying flood risk communication. They found that people who have experienced a flood are more aware of the risks. Conversely, groups that have not lived through floods typically don't understanding various flood risks such as storm surges and flash floods. And while first responders often engage in table-top exercises and drills — very important for their readiness to respond — there are only a few examples of entire communities actively participating in warning drills.

Messages used to communicate flood risk also matter, but people need to receive them. To that end, Keri's teams have worked with the Texas Water Development Board to develop resources that help local flood officials sort through and prioritize information about a flood hazard so they can share what is most valuable with their local communities.

The commonly used "Turn Around Don't Drown" message, while valuable, may not resonate equally with all groups. Newly developed and tested messages such as "Keep Your Car High and Dry" appeal specifically to young adults who typically feel invincible but don't want their prized vehicles damaged. While more research is needed, this is an example of progress in understanding an important aspect of flood communication: how recipients of the information make decisions.

Related: Texas flood devastation revealed in before-and-after satellite images

Interviews conducted by researchers often include responses along these lines: "Another flash flood warning. We get these all the time. It's never about flooding where I am." This common refrain reveals a fundamental challenge in flood communication. When people hear "flood warning," they often think of different things, and interpretations can vary depending on a person's proximity to the flooding event.

Some people equate flood warnings with streamflow gauges and sensors that monitor water levels — the technical infrastructure that triggers alerts when rivers exceed certain thresholds. Others think of mobile phone alerts, county- or geographic-specific notification systems, or even sirens.

Beyond technologies and digital communication, warnings still come through informal networks in many communities. Emergency managers directly coordinate with and share information with major businesses and organizations, saying, "Hey, John, be sure you have somebody up tonight watching the National Weather Service alerts and rivers."

This human-centered approach, similar to neighborhood-level systems we have studied in Japan, can provide direct confirmation that warnings have been received. This is something mass media and mobile systems cannot guarantee, especially during infrastructure failures such as power and cell tower outages.

Effective messages

Research shows that effective warning messages need to include five critical components: a clear hazard description, location-specific information, actionable guidance, timing cues and a credible source. The Federal Emergency Management Agency's integrated public alert and warning system message design dashboard assists authorities in rapidly drafting effective messages.

This warning system, known as IPAWS, provides nationwide infrastructure for wireless emergency alerts and Emergency Alert System messages. While powerful, IPAWS has limitations − not all emergency managers are trained to use it, and messages may extend beyond intended geographic areas. Also, many older mobile devices lack the latest capabilities, so they may not receive the most complete messages when they are sent.

Hyperlocal community opt-in systems can complement IPAWS by allowing residents to register for targeted notifications. These systems, which can be run by communities or local agencies, face their own challenges. People must know they exist, be willing to share phone numbers, and remember to update their information. Social media platforms add another communication channel, with emergency managers increasingly using social media to share updates, though these primarily reach only certain demographics, and not everyone checks social media regularly.

The key is redundancy through multiple communication channels. Research has found that multiple warnings are needed for people to develop a sense of urgency, and the most effective strategy is simple: Tell another person what's going on. Interpersonal networks help ensure the message is delivered and can prompt actions. As former Natural Hazards Center Director Dennis Mileti observed: The wireless emergency alerts system "is fast. Mama is faster."

Warning fatigue

Professionals from the National Weather Service, FEMA and the Federal Communications Commission, along with researchers, are increasingly concerned about warning fatigue — when people tune out warnings because they receive too many of them.

However, there is limited empirical data about how and when people experience warning fatigue — or about its impact.

This creates a double bind: Officials have an obligation to warn people at risk, yet frequent warnings can desensitize recipients. More research is needed to determine the behavioral implications of and differences between warnings that people perceive as irrelevant to their immediate geographic area versus those that genuinely don't apply to them. This distinction becomes especially critical when people might drive into flooded areas outside their immediate vicinity.

The key to effective emergency communication is to develop messages that resonate with specific audiences and build community networks that complement technological systems. We are now studying how to do this effectively in the United States and internationally. It's also important to apply behavioral insights to the design of every level of communication warning systems. And it's important to remember to test not just the technology but the entire end-to-end system, from threat identification to community response.

Finally, maintaining true redundancy across multiple communication channels is an important strategy when trying to reach as many people as possible. Technology supports human decision-making, but it doesn't replace it.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

New satellite images have captured the trail of devastation left in the wake of Texas' deadly flash floods earlier this week.

The flooding, which began in the early hours of Friday (July 4), has been catastrophic, with 121 people reported to have died and at least 150 people still missing, at the time of writing.

Most of the deaths have occurred in Kerr County, where extreme rainfall caused the Guadalupe River to swell and burst its banks.

Space technology company Maxar Technologies has released satellite images that show the Guadalupe River before and after the flooding. Click on the right of the images below to see how the landscape changed as a result of the floods.

Related: Why were the Texas flash floods so catastrophic?

These images show the Ingram Dam, located in Kerr County, before and after the devastating floods. The first image was taken in July 2022, while the second was taken on Tuesday (July 8). Last Friday, water levels in the river rose by more than 26 feet (8 meters) in just 45 minutes.

These two satellite images show vegetation along the Guadalupe River before and after the flooding. The first image was taken in June 2023, while the second was taken on July 8. Much of the vegetation visible in the first image has been washed out in the second.

These before-and-after photos from along Texas State Highway 39 illustrate some of the catastrophic damage the waters caused. In the second image, taken after the flooding on July 8, homes just above the highway have been swept away.

These floods are the deadliest inland flooding in the U.S. since 1976, when the Big Thompson Canyon flood killed 144 people in Colorado, The Associated Press reported.

These before-and-after shots show how the river expanded and swept through trees, causing many to tumble down. The first satellite image was taken in June 2023, while the second was taken on July 8. Many trees have either fallen or are completely missing in the second image.

In the early hours on Friday (July 4), a large storm dropped about a foot of water in just a few hours over the Texas Hill Country. In 45 minutes, the water ran down the region's slopes into the Guadalupe River, which rose by more than 26 feet (8 meters) and burst its banks. In Kerr County, the deluge of water swept away people, homes and infrastructure and, as of July 8, more than 100 people have died.

So what caused such catastrophic flooding?

First off, the area is prone to flash flooding. In fact, Texas leads the U.S. in deaths due to flood. This is partially because of its hilly terrain and semiarid soil, which does not absorb much moisture, Hatim Sharif, a professor of civil and environmental engineering at the University of Texas, San Antonio, wrote for The Conversation. "The water sheets off quickly and the shallow creeks can rise fast."

What is flash flooding, and why was it so bad in Texas?

Flash floods are a special type of flood "usually characterized by raging torrents after heavy rains that rip through river beds, urban streets, or mountain canyons sweeping everything before them," according to the National Weather Service. They can occur within minutes or a few hours of excessive rainfall.

Texas is no stranger to flooding, and this particular area is known as "Flash Flooding Alley," Daniel Swain, a climate scientist at UCLA, told Live Science. "All the ingredients were in place for a potentially extreme rainfall," he said.

The major driver of these floods was the sheer quantity of water, Swain said. "An extraordinarily persistent torrential thunderstorm just sat over the same watershed for several hours and slowly propagated down that watershed in the direction of the flood wave."

Related: Climate change made April's catastrophic floods worse, report finds

The remnants of Tropical Storm Barry, which hit near Mexico last week, had already added moisture and instability into the atmosphere. Then, an easterly wind blew this saturated air inland, forcing the warm atmospheric air upward as it moved toward Texas. That air "rises into thunderstorms producing torrential rainfall, with very extreme rainfall rates on the order of two or three inches per hour and this is sustained over hours," Swain said.

In Texas, that created an extreme flash flood localized on one river system.

Can scientists predict flash floods?

While meteorologists can identify conditions that tend to fuel flash floods and regions that are prone to them, predicting exactly where and when one is likely to occur is very difficult, one expert told Live Science.

"It is very difficult to predict intense rainfall and flash flooding," said Jess Neumann, a geographer who specializes in flood risk management at the University of Reading in the U.K. "There is always uncertainty in a forecast in terms of the exact amount of rain that will fall, where precisely it will fall, and how that water will behave and move across the land once it reaches the ground."

In this case, the National Weather Service did issue a flash flood warning at 1:26 a.m. local time on Friday, and posted a follow-up emergency flash flood warning on X at 4:06 a.m.

Some pundits have suggested that recent mass layoffs at the National Oceanic and Atmospheric Administration, which runs the National Weather Service, may have hindered surveillance efforts ahead of these events. For example, KXAN reported that the warning coordination meteorologist at the National Weather Service Austin/San Antonio office, took early retirement in the wake of the NOAA funding cuts. The office is responsible for the areas most affected by the flash flood.

However, Swain said that the predictions from the office were as good as could be expected. “The real failure here was in the communication of that forecast and the failure of local authorities to have a plan of action and to put it into place to keep people safe,” he said.

Will flash flooding get worse in future?

As the climate warms, scientists warn that extreme rainfall events — such as the one that led to the Texas flash flood — will become more common. A warmer atmosphere can hold more water vapor, which will eventually fall to Earth as precipitation.

A fundamental law of thermodynamics known as the Clausius-Clapeyron equation, which describes the relationship between temperature and vapor pressure, predicts that for every degree Celsius that the atmosphere's temperature rises, its water-vapor-carrying capacity will increase by about 7%.

However, it might be even worse for flash flooding, Swain said. "When you talk about the very most extreme rain events — and, in particular, the very most extreme thunderstorm downpours — they increase at an even faster rate that is close to double that."

There are many places in the US, including several in southeastern states, which have a heightened flash flood risk due to their hilly geography and proximity to the Gulf of Mexico.

“When you have immediate proximity to an exceptionally warm body of water, occasional storm systems that push air rapidly upslope and unstable atmospheres that can occur, you can see these sorts of events,” said Swain. “The number of places where this at least is occasionally relevant is quite widespread.”

A NASA astronaut has captured an electrifying image of Earth from space, featuring a gigantic, jellyfish-shaped "sprite" of red lightning shooting upwards above a thunderstorm in North America. The rare phenomenon is still poorly understood, despite being studied for more than 30 years.

Nichole Ayers, the pilot of SpaceX's Crew-10 mission and member of International Space Station (ISS) expeditions 72 and 73, snapped the striking photo on Thursday (July 3) as the space station passed above a large thunderstorm hanging over parts of Mexico and the southern U.S., including California and Texas.

"Just. Wow. As we went over Mexico and the U.S. this morning, I caught this sprite," Ayers wrote on the social platform X. "Sprites are TLEs or Transient Luminous Events, that happen above the clouds and are triggered by intense electrical activity in the thunderstorms below," she added.

TLEs are a range of visual phenomena that occur in the upper atmosphere during thunderstorms, including upward-shooting blue jets and UFO-like rings of light, known as ELVES. However, the most common TLEs are sprites, like the one photographed by Ayers.

Sprites are sometimes referred to as jellyfish because they contain multiple branches of light that spread out like tentacles, while others call them "carrots" because they can be accompanied by fainter tendrils that trail behind them in the opposite direction like plant roots. They are often associated with large thunderstorms, including those produced by hurricanes.

Related: Electrifying time-lapse image captures 100 lightning bolts torching the sky

Sprites can range in size and shape, with the largest reaching up to 50 miles (80 kilometers) above Earth's surface. They have a red color because they interact with nitrogen in the upper atmosphere, according to NASA's Earth Observatory.

Sprites were first properly observed in the 1950s by airline passengers but were not photographed until 1989. The red jellyfish have also been spotted in the atmosphere of Jupiter, and they are thought to occur on Saturn and Venus, according to Live Science's sister site Space.com.

But despite years of research, researchers are still unsure why some lightning strikes cause sprites and others don't, according to FOX Weather.

TLEs from space

Sprites and other TLEs can be photographed from Earth's surface if the conditions are right. However, ISS astronauts are uniquely well-positioned to see TLEs and frequently see the flashes of lightning strikes at the same time, providing useful data to help researchers figure out how these phenomena work.

"We have a great view above the clouds, so scientists can use these types of pictures to better understand the formation, characteristics, and relationship of TLEs to thunderstorms," Ayers wrote.

One of the most recent examples of this was in March, when an unnamed ISS astronaut snapped faint red sprites glowing at the end of a "gigantic jet" of lightning shooting upward above New Orleans.

Another excellent example was an eerie red jellyfish that seemed to float independently in Earth's atmosphere, high above a flash of lightning in June 2024, Space.com previously reported.

A rare snowfall in the driest place on Earth has halted operations of one of the world's premier telescope arrays, and climate change may mean the observatory will face more extreme weather events like this in the future.

The snow has blanketed part of the Atacama Desert, which gets less than an inch of rainfall per year and is home to home the Atacama Large Millimeter/submillimeter Array (ALMA), a large network of radio telescopes in northern Chile.

The snowfall occurred over ALMA's Operations Support Facility, located at an altitude of 9,500 feet (2,900 meters) and about 1,050 miles (1,700 kilometers) north of Santiago. Scientific operations have been suspended since Thursday (June 26).

"There hasn't been a record of snowfall at the base camp for over 10 years. It doesn't snow every day at ALMA!" ALMA representatives told Live Science via WhatsApp.

ALMA's radio telescope array is perched high on the Chajnantor Plateau — a desert plain at 16,800 feet (5,104 m) in Chile's Antofagasta region — typically sees three snowfalls a year. The high plateau shared by Chile, Bolivia and Peru typically experiences snowstorms during two seasons: in February, during the "Altiplanic Winter," driven by moist air masses from the Amazon; and from June to July, during the Southern Hemisphere's winter, said Raúl Cordero, a climatologist at the University of Santiago.

"In winter, some storms are fueled by moisture from the Pacific, which can extend precipitation even to the Atacama Desert's coastal areas," Cordero told Live Science. At elevations above 16,400 feet (5,000 m), annual snowfall ranges from 8 to 31 inches (20 to 80 centimeters).

However, snowfall at 3,000 meters (9,840 feet), where ALMA's base camp is located, "is much less frequent," Cordero noted.

This week's snowfall was triggered by unusual atmospheric instability affecting northern Chile. The Chilean Meteorological Directorate issued a snow and wind alert due to the passage of a "cold core" through the region, said meteorologist Elio Brufort. "We issued a wind alert for the Antofagasta region and areas further north, with gusts reaching 80 to 100 km/h [50-62 mph]," Brufort said to the local press.

The phenomenon was accompanied by heavy rainfall that occurred farther north, causing a stream to swell and damage several properties. Schools were ordered to close, and power outages and landslides were reported. So far, no casualties have been reported. A weather event of this magnitude has not been seen in nearly a decade.

Extreme conditions paralyze ALMA

As of Friday, ALMA reported to Live Science that the snowstorm remained active over the Chajnantor Plateau, so scientific operations continued to be suspended to protect the antennas from extreme weather conditions. Early Thursday morning, the observatory activated its "survival mode" safety protocol: In addition to the snowfall, temperatures had plummeted to 10 degrees Fahrenheit (minus 12  degrees Celsius) — with a wind chill of minus 18 F (minus 28 C) — making work at the high-altitude camp extremely difficult.

As part of this protocol, all of ALMA's large antennae have been reoriented downwind, helping to minimize potential damage from snow buildup or strong gusts.

"Once the storm passes, snow-clearing teams are immediately activated to visually inspect each antenna before resuming observations," ALMA representatives said. "This has to happen fast, as some of the best observing conditions occur just after a snowfall: the cold helps lower air humidity, which is what most interferes with our measurements."

ALMA, which consists of 66 high-precision antennae spread across the Chajnantor Plateau, is an international collaboration that forms the most powerful radio telescope on the planet — and one designed to handle extreme weather events like this.

The fact that the snow halted operations raises questions about the array's operations as the climate warms.

The Atacama Desert typically receives only 0.04 to 0.6 inch (1 to 15 millimeters)of precipitation per year, and many areas can go years without recording any measurable rain or snow.

Could events like this become more frequent? "That's a good question," Cordero replied.

While it's still too early to link lower-altitude snowfalls in the desert directly to climate change, "climate models predict a potential increase in precipitation even in this hyper-arid region," he concluded. "We still can't say with certainty whether that increase is already underway."

This striking satellite photo shows multiple examples of a rare meteorological phenomenon, known as "von Kármán vortices," swirling off at least six different islands in the Atlantic Ocean. Very rarely have so many of these swirling cloud trails been seen at once and over such a large area.

Von Kármán vortices occur when a prevailing wind encounters a landmass, disturbing the airflow and creating "a double row of vortices which alternate their direction of rotation," according to the National Oceanic and Atmospheric Administration (NOAA). These vortices then propagate downstream of the landmass and become visible when clouds get caught up in them.

In this photo, giant cloud swirls collectively cover an area of around 260,000 square miles (670,000 square km), making this one of the most widespread examples of concurrent vortices ever seen, according to NASA's Earth Observatory.

The most intricate swirls in the photo are seen in the vortices off Madeira, a Portuguese archipelago, at the top of the image (see below). Here, the high concentration of clouds reveals the detailed movements of the disturbed air in exceptional detail.

Related: See all the best images of Earth from space

Less-defined swirling trails are also seen trailing off the Spanish Canary Islands. From left to right, these are: La Palma, El Hierro, La Gomera, Tenerife and Gran Canaria. If you look closely (see below), you can see that the vortices from La Gomera and Tenerife interfere with each other, almost canceling them out completely.

Madeira and the Canary Islands are among the best places on Earth to see von Kármán vortices, according to the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). This is because they have high peaks, high temperatures and are reasonably separated from their respective continents.

These swirls are also commonly spotted coming from Guadalupe, a group of six French-owned islands in the Caribbean, on the opposite side of the Atlantic. On rare occasions, the swirls have also coincided with other phenomena, such as a warped "double rainbow."

While the vortices mostly occur in tropical climates, they can also be seen in the Arctic, such as on Svalbard's Bear Island, where they can sometimes appear alongside swirling algal blooms.

On average, a pair of von Kármán vortices is created somewhere on Earth every eight hours, according to EUMESTAT.

A thunderstorm "ring of fire" has erupted along the edge of the massive "heat dome" currently smothering much of the eastern half of the United States. And if that wasn't enough wild weather, the first named tropical storm of the season has also emerged — and already fizzled out — in the Atlantic.

The heat dome is being caused by an area of high pressure in the atmosphere that has trapped warm air beneath it, like a giant lid on a pot. The dome has been contributing to sweltering temperatures in the Central and Eastern U.S. since the end of last week, even raising temperatures in New York City to 100 degrees Fahrenheit (38 Celsius), a height not seen since 2013, The Associated Press reported.

Clouds have difficulty forming inside a heat dome, where most of the air is warm, but it's a different story on the dome's edges, where the air is cooler, according to AccuWeather. A chain of thunderstorms, or ring of fire, often rides the edge of a massive heat dome, and that's proven to be the case this time.

"AccuWeather expert meteorologists are monitoring an arc of severe thunderstorms stretching 2,200 miles [3,500 kilometers] from northern Mexico to New England and southeastern Canada this week along the western and northern edges of the heat dome," representatives for AccuWeather wrote in a statement released Tuesday (June 24).

A "ring of fire" is what meteorologists call thunderstorms and heavy rain riding the rim of a high-pressure ridge, but given that this weather is marked by extensive rain that can produce flooding, the name is a little confusing. There's also a chain of volcanoes around the Pacific Ocean with the same name.

Related: In 2025, Tornado Alley has become almost everything east of the Rockies — and it's been a violent year

The heat dome is forecast to weaken in the second half of this week. However, the National Weather Service (NWS) has warned that "extremely dangerous" heat will nonetheless continue throughout that time, affecting areas from the Midwest to the East Coast. The heat won't completely subside by the weekend, either, but it will ease a bit in large parts of the eastern U.S., according to the NWS.

Heat waves have become more common and intense with climate change. The frequency of atmospheric patterns linked to extreme summer weather, including heat domes and flooding, has nearly tripled since the 1950s, according to a study published June 16 in the journal PNAS.

Storm Andrea

While many U.S. states have been experiencing sweltering heat, the first named tropical storm of the season emerged in the Atlantic. Tropical Storm Andrea, also called Tropical Cyclone Andrea, formed in the middle of the Atlantic Ocean on Tuesday (June 24), but posed "no threat to land," according to the National Hurricane Center.

The storm sustained winds of more than 39 miles per hour (63 kilometers per hour), meeting the threshold to be a named tropical storm. However, the storm quickly weakened, The Associated Press reported.

Before dissipating, Andrea never grew strong enough to become a hurricane, which have maximum sustained wind speeds of at least 74 mph (119 km/h)

Researchers have found that the 2025 Atlantic hurricane season could be more severe than normal. The season, which runs from June 1 to Nov. 30, has a 60% chance of "above-normal" activity, according to the National Oceanic and Atmospheric Administration (NOAA). Climate models predict that hurricanes will become more intense as the planet warms up.

A major heat wave is set to scorch the central and eastern U.S., with millions of Americans facing potentially record-breaking extreme heat.

Temperatures and humidity will rise as much of the country finds itself under a "heat dome," The Associated Press reported. A heat dome occurs when an area of high pressure in the atmosphere traps warm air beneath, effectively like placing a lid on top of a pot.

The National Weather Service (NWS) has warned that "extremely dangerous" levels of heat are likely over the weekend and into next week, as sunny days, light winds and a lack of overnight cooling worsen high temperatures.

"Heat is likely to reach dangerous levels over much of the Central and Eastern U.S.," an NWS representative wrote in a weather update posted on Facebook. "Particular concern exists for the Ohio, Valley, Eastern Great Lakes, Interior South, and much of the East Coast, where the heat will be more persistent."

Meteorologists predict that the heat wave will hit the central U.S. between Friday (June 20) and Sunday (June 22), before making its way to the East Coast next week.

Temperatures are expected to reach nearly 100 degrees Fahrenheit (38 degrees Celsius) across the central and eastern U.S. (exceeding 100 F in some areas). Affected cities such as Denver, Washington, D.C., and New York City will experience several consecutive days of heat, weather website AccuWeather reported in a forecast.

Related: 'Heat is the final boss. Heat is a different beast': The planetary peril no one will be able to avoid

"The magnitude and longevity of this heat wave will be a shock to the system," AccuWeather senior meteorologist Chad Merrill said in the forecast.

Moist ground will absorb some of the sun's energy, preventing temperatures from exceeding 100 F over much of the affected area. However, the heat will also evaporate this moisture, adding to what are already expected to be humid conditions, according to AccuWeather.

The NWS warned the anticipated levels of heat can be dangerous to anyone who doesn't have effective cooling systems or adequate hydration, and is especially risky to people taking part in lengthy outdoor activities.

Our warming world

Heat waves are becoming more frequent and intense with climate change. That doesn't necessarily mean climate change is responsible for the latest heat wave, but scientists have long predicted that there will be more of these kinds of extreme weather events as the planet warms.

Last year was the hottest year for global temperatures since records began, while 2025 has already been marked by a string of record-breaking or near-record-breaking warm months.

Violent tornado outbreaks, like the storms that tore through parts of St. Louis and London, Kentucky, on May 16, have made 2025 seem like an especially active, deadly and destructive year for tornadoes.

The U.S. has had more reported tornadoes than normal — over 960 as of May 22, according to the National Weather Service's preliminary count.

That's well above the national average of around 660 tornadoes reported by that point over the past 15 years, and it's similar to 2024 — the second-most active year over that same period.

I'm an atmospheric scientist who studies natural hazards. What stands out about 2025 so far isn't just the number of tornadoes, but how Tornado Alley has encompassed just about everything east of the Rockies, and how tornado season is becoming all year.

Why has 2025 been so active?

The high tornado count in 2025 has a lot to do with the weather in March, which broke records with 299 reported tornadoes — far exceeding the average of 80 for that month over the past three decades.

March's numbers were driven by two large tornado outbreaks: about 115 tornadoes swept across more than a dozen states March 14-16, stretching from Arkansas to Pennsylvania; and 145 tornadoes hit March 31 to April 1, primarily in a swath from Arkansas to Iowa and eastward. The 2025 numbers are preliminary pending final analyses.

While meteorologists don't know for sure why March was so active, there were a couple of ingredients that favor tornadoes:

• First, in March the climate was in a weak La Niña pattern, which is associated with a wavier and stormier jet stream and, often, with more U.S. tornadoes.
• Second, the waters of the Gulf were much warmer than normal, which feeds moister air inland to fuel severe thunderstorms.

By April and May, however, those ingredients had faded. The weak La Niña ended and the Gulf waters were closer to normal.

April and May also produced tornado outbreaks, but the preliminary count over most of this period, since the March 31-April 1 outbreak, has actually been close to the average, though things could still change.

What has stood out in April and May is persistence: The jet stream has remained wavy, bringing with it the normal ebb and flow of stormy low-pressure weather systems mixed with sunny high-pressure systems. In May alone, tornadoes were reported in Colorado, Minnesota, Delaware, Florida and just about every state in between.

Years with fewer tornadoes often have calm periods of a couple of weeks or longer when a sunny high-pressure system is parked over the central U.S. However, the U.S. didn't really get one of those calm periods in spring 2025.

Tornado Alley shifts eastward

The locations of these storms have also been notable: The 2025 tornadoes through May have been widespread but clustered near the lower and central Mississippi Valley, stretching from Illinois to Mississippi.

That's well to the east of traditional Tornado Alley, typically seen as stretching from Texas through Nebraska, and farther east than normal. April through May is still peak season for the Mississippi Valley, though it is usually on the eastern edge of activity rather than at the epicenter. The normal seasonal cycle of tornadoes moves inland from near the Gulf Coast in winter to the upper Midwest and Great Plains by summer.

Over the past few decades, the U.S. has seen a broad shift in tornadoes in three ways: to the east, earlier in the year and clustered into larger outbreaks.

Winter tornadoes have become more frequent over the eastern U.S., from the southeast, dubbed Dixie Alley for its tornado activity in recent years, to the Midwest, particularly Kentucky, Illinois and Indiana.

Meanwhile, there has been a steady and stark decline in tornadoes in the "traditional" tornado season and region: spring and summer in general, especially across the Great Plains.

It may come as a surprise that the U.S. has actually seen a decrease in overall U.S. tornado activity over the past several decades, especially for intense tornadoes categorized as EF2 and above. There have been fewer days with a tornado. However, those tornado days have been producing more tornadoes. These trends may have stabilized over the past decade.

Deadlier tornadoes

This eastward shift is likely making tornadoes deadlier.

Tornadoes in the Southeastern U.S. are more likely to strike overnight, when people are asleep and cannot quickly protect themselves, which makes these events dramatically more dangerous. The tornado that hit London, Kentucky, struck after 11 p.m. Many of the victims were over age 65.

The shift toward more winter tornadoes has also left people more vulnerable. Since they may not expect tornadoes at that time of year, they are likely to be less prepared. Tornado detection and forecasting is rapidly improving and has saved thousands of lives over the past 50-plus years, but forecasts can save lives only if people are able to receive them.

This shift in tornadoes to the east and earlier in the year is very similar to how scientists expect severe thunderstorms to change as the world warms. However, researchers don't know whether the overall downward trend in tornadoes is driven by warming or will continue into the future. Field campaigns studying how tornadoes form may help us better answer this question.

Remember that it only takes one

For safety, it's time to stop focusing on spring as tornado season and the Great Plains as Tornado Alley.

Tornado Alley is really all of the U.S. east of the Rockies and west of the Appalachians for most of the year. The farther south you live, the longer your tornado season lasts.

Forecasters say it every year for hurricanes, and we badly need to start saying it for tornadoes too: It only takes one to make it a bad season for you or your community. Just ask the residents of London, Kentucky; St. Louis; Plevna and Grinnell, Kansas; and McNairy County, Tennessee.

Listen to your local meteorologists so you will know when your region is facing a tornado risk. And if you hear sirens or are under a tornado warning, immediately go to your safe space. A tornado may already be on the ground, and you may have only seconds to protect yourself.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Satellites recently snapped a giant cloud of "Saharan dust" blowing out to sea from the world's largest hot desert. The hazy mass later traveled more than 4,000 miles (6,500 kilometers) to North America, where it polluted the skies of Florida and other states.

In the early hours of May 28, 2025, a large cloud of dust and sand began to blow out from the Sahara and over the Atlantic Ocean, according to a statement from the National Oceanic and Atmospheric Administration (NOAA). Around a week later, on June 4, the cloud made landfall in Florida, with the plume also reaching Louisiana, Texas and other parts of the Gulf Coast. En route, it also briefly filled the skies of several Caribbean nations, including Puerto Rico and the Bahamas.

A photo captured by the GOES-19 satellite, which is co-run by NASA and NOAA, revealed the cloud as it first began its transatlantic journey. At the time, it covered an area of roughly 240,000 square miles (620,000 square km) between Cabo Verde — an archipelago of 10 volcanic islands in the mid-Atlantic — and the coast of West Africa, including the shorelines of Mauritania, Senegal, Gambia and Guinea-Bissau.

The dust cloud was a "particularly robust, comma-shaped plume," representatives from the Cooperative Institute for Research in the Atmosphere (CIRA) at Colorado State University wrote on Bluesky. However, soon after the photo was taken, the cloud dispersed, making it "appear larger in size."

Astronauts on board the International Space Station (ISS) also captured shots of the plume as it moved across the Atlantic, Live Science's sister site Space.com reported.

Related: See all the best images of Earth from space

In Florida, the plume caused a brief reduction in air quality that may have impacted people with respiratory conditions. The state's skies remained hazy for around 48 hours before the majority of the dust settled — some of which was later visible on windows and cars.

A second, smaller plume reached the U.S. between June 13 and 15.

Saharan dust can have several other surprising effects. "When it reaches the U.S., it can cause hazy skies as well as vivid sunrises and sunsets as the sun's rays scatter the dust in the atmosphere," NOAA representatives wrote. "It can even suppress thunderstorm development over locations where the dust is especially thick."

Dust plumes

Saharan dust gets whipped up by strong gusts of wind, which occur much more frequently in deserts than other environments, and can reach several miles above Earth's surface, according to the U.K. Met Office. This mainly happens between late spring and early fall.

Once the dust is airborne, it hovers above the desert in a region known as the "Saharan Air Layer" — a roughly 2.5-mile-wide (4 km) band of very dry air that forms around 1 mile (1.6 km) above the Sahara desert. Every three to five days, the accumulated dust gets blown out to sea, and if there is enough of it, the particulates form large plumes that can travel across entire oceans, according to NOAA's Atlantic Oceanographic and Meteorological Laboratory, which helps monitor the Saharan Air Layer.

Saharan dust plumes of various sizes reach the U.S. every year, usually peaking in intensity between June and August.

One of the most famous examples in recent years was the "Godzilla" plume, which hit large parts of the southern U.S. in June 2020. During this two-week-long event, the amount of dust reached the highest levels since satellites began tracking plumes 18 years previously, according to a 2021 study.

A new artificial intelligence (AI) model can predict major weather events faster and more accurately than some of the world's most widely used forecasting systems.

The model, called Aurora, is trained on more than 1 million hours of global atmospheric data, including weather station readings, satellite images and radar measurements. Scientists at Microsoft say it's likely the largest dataset ever used to train a weather AI model.

Aurora correctly forecast that Typhoon Doksuri would strike the northern Philippines four days before the storm made landfall in July 2023. At the time, official forecasts placed the storm's landfall over Taiwan — several hundred miles away.

It also outperformed standard forecasting tools used by agencies, including the U.S. National Hurricane Center and the Joint Typhoon Warning Center. It delivered more accurate five-day storm tracks and produced high-resolution forecasts up to 5,000 times faster than conventional weather models powered by supercomputers.

More broadly, Aurora beat existing systems in predicting weather conditions over a 14-day period in 91% of cases, the scientists said. They published their findings May 21 in the journal Nature.

Future forecasting

Researchers hope Aurora and models like it could support a new approach to predicting environmental conditions called Earth system forecasting, where a single AI model simulates weather, air quality and ocean conditions together. This could help produce faster and more consistent forecasts, especially in places that lack access to high-end computing or comprehensive monitoring infrastructure.

Related: Google builds an AI model that can predict future weather catastrophes

Aurora belongs to a class of large-scale AI systems known as foundation models — the same category of AI models that power tools like ChatGPT.

Foundation models can be adapted to different tasks because they're designed to learn general patterns and relationships from large volumes of training data, rather than being built for a single, fixed task. In Aurora's case, the model learns to generate forecasts in a matter of seconds by analyzing weather patterns from sources like satellites, radar and weather stations, as well as simulated forecasts, the researchers said.

The model can then be fine-tuned for a wide range of scenarios with relatively little extra data — unlike traditional forecasting models, which are typically built for narrow, task-specific purposes and often need retraining to adapt.

The diverse dataset Aurora is trained on not only results in greater accuracy in general versus conventional methods, but also means the model is better at forecasting extreme events, researchers said.

In one example, Aurora successfully predicted a major sandstorm in Iraq in 2022, despite having limited air quality data. It also outperformed wave simulation models at forecasting ocean swell height and direction in 86% of tests, showing it could extract useful patterns from complex data even when specific inputs were missing or incomplete.

"It's got the potential to have [a] huge impact because people can really fine tune it to whatever task is relevant to them … particularly in countries which are underserved by other weather forecasting capabilities," study co-author Megan Stanley, a senior researcher at Microsoft, said in a statement.

Microsoft has made Aurora's code and training data publicly available for research and experimentation. The model has been integrated into services like MSN Weather, which itself is integrated into tools like the Windows Weather app and Microsoft's Bing search results.

Rainclouds and thunderstorms off the Pacific coast of Mexico will likely trigger the first Western Hemisphere tropical storm of the 2025 season in the coming hours — with a chance this storm could strengthen into a hurricane, meteorologists say.

There is a near 100% chance that a tropical storm will form in the next 48 hours, according to the National Oceanic and Atmospheric Administration (NOAA)'s National Hurricane Center (NHC). Once the storm is confirmed, its name will be tropical storm Alvin, and it will have formed just two weeks after the beginning of the Eastern Pacific hurricane season on May 15.

As of 7:50 a.m. EDT on Wednesday (May 28), an area of low pressure producing heavy rain clouds and storms was located south of the coastal Mexican city of Acapulco. The system was moving in a west to northwest direction at a speed of about 10 miles per hour (16 km/h), according to the NHC.

"An elongated area of low pressure located several hundred miles south of the coast of southern Mexico continues to produce showers and thunderstorms, but the system still lacks a well-defined circulation," NHC meteorologists wrote on a map showing the location of the system. "Environmental conditions remain favorable for further development, and a tropical depression or tropical storm is expected to form later today or tonight."

The system's current direction of travel suggests that any tropical depression or storm born from it will fizzle out in the Eastern Pacific without making landfall, according to The Weather Channel — but it's possible that the system could curl around and migrate northeastward, with stormy weather hitting Mexico's coast around Saturday (May 31).

A tropical storm is a type of tropical cyclone with maximum sustained wind speeds between 39 and 73 mph (63 to 117 km/h). According to NOAA's National Ocean Service, meteorologists use the term "tropical cyclone" to describe any organized system of clouds and thunderstorms that originates over tropical or subtropical waters, and then starts to rotate in a closed, low-level vortex. The weakest tropical cyclones are called tropical depressions, and they are characterized by winds slower than 39 mph. Once maximum sustained wind speeds exceed 73 mph, tropical cyclones are called hurricanes.

Related: La Niña is dead — what that means for this year's hurricanes and weather

Tropical cyclones are typically caused by pre-existing weather disturbances, but they also require high moisture and relatively light winds to form, according to the National Ocean Service. If the conditions persist for long enough, their combined effects will whip up violent winds and large waves, and potentially trigger torrential rain and coastal flooding.

According to The Weather Channel, a very strong Alvin could transform into a hurricane as soon as Thursday (May 29). Regardless of whether Alvin makes landfall, high surf, rip currents and heavy rain could hit parts of Mexico's coast later this week if the tropical storm develops, the broadcaster said.

It's unclear whether the storm could impact the U.S. West Coast, but scientists say the Southwest could receive more moisture than usual.

Alvin may be the Western Hemisphere's first tropical storm of 2025, but it's very unlikely to be the last. The Eastern Pacific hurricane season starts two weeks before the Atlantic hurricane season, which runs every year from June 1 through Nov. 30, peaking between mid-August and mid-October.

This year's Atlantic hurricane season is expected to be particularly ferocious, with NOAA predicting above-normal activity and between 13 and 19 named tropical storms. Six to 10 of these storms will likely strengthen into hurricanes, and three to five could become major hurricanes, forecasters say.

The forecasted hyperactivity of 2025’s Atlantic hurricane season follows from 2024, as record-shattering ocean temperatures fuelled the rapid intensification of hurricanes such as Beryl, Helene and Milton, which sowed devastation across Florida and the Caribbean.

"For the second straight year, NOAA predicts an above-average hurricane season," CBS reporter Karen Hua said in a video. "Five hurricanes made landfall in the U.S. last season, causing more than $100 billion worth of damage."

While 2025's Atlantic hurricane season may bring above-normal tropical cyclone activity, NOAA predicts normal to below-average activity in the Pacific. In terms of numbers, forecasters think there could be 1 to 4 tropical cyclones between now and November.

2025's Atlantic hurricane season is expected to be more ferocious than usual, according to forecasts by the National Oceanic and Atmospheric Administration (NOAA).

The hurricane season, which begins on June 1 and runs until Nov. 30, is predicted to have a 60% chance of above-normal activity. There are expected to be 13 to 19 named tropical storms — with wind speeds of 39 mph (63 km/h) or higher — six to 10 of which are expected to become hurricanes, with three to five of these hitting major hurricane status — with wind speeds above 111 mph (179 km/h).

Years with normal levels of hurricane activity experience 14 named storms, seven hurricanes and three major hurricanes.

"NOAA and the National Weather Service are using the most advanced weather models and cutting-edge hurricane tracking systems to provide Americans with real-time storm forecasts and warnings," U.S. Secretary of Commerce Howard Lutnick said in a statement on May 22.

Tropical storms usually form over the warm ocean waters near the tropics. If a storm becomes a rotating, organized thunderstorm system with wind speeds below 39 mph (63 km per hour), it is defined as a tropical depression, but once wind speeds exceed that level, the event is considered to be a tropical storm and is given a name from a pre-decided list. Storms become hurricanes once wind speeds reach 74 mph (119 km/h), with hurricanes being subdivided into five categories. Category 3, 4 and 5 hurricanes are classified as major hurricanes.

The hurricane season runs when ocean and atmospheric conditions are most favorable for tropical storms. Tropical storms need warm sea surface temperatures to form and strengthen, as well as little difference in wind speed and direction between the lower and upper levels of the atmosphere — known as vertical wind shear — which enables storms to organize vertically. Peak hurricane activity usually happens in September, when ocean temperatures and atmospheric conditions are most optimal. Before June and after November the ocean is generally too cool, and wind shear is higher.

Related: La Niña is dead — what that means for this year's hurricanes and weather

Above-average hurricane activity is predicted this year because of warmer-than-average ocean temperatures and weak wind shear, allowing for more frequent and more powerful storms to form.

This year's Atlantic storms will be named, in order of appearance: Andrea, Barry, Chantal, Dexter, Erin, Fernand, Gabrielle, Humberto, Imelda, Jerry, Karen, Lorenzo, Melissa, Nestor, Olga, Pablo, Rebekah, Sebastien, Tanya, Van, and Wendy.

NOAA has a 70% confidence in its predictions of this year's storm frequency. Last year, before the 2024 hurricane season, NOAA predicted that there would be 17 to 25 named storms, eight to 13 hurricanes, and four to seven major hurricanes — an even more severe forecast than this year's outlook. However, the season actually resulted in 18 named storms, 11 hurricanes, and five major hurricanes.

Hurricane Beryl, which made landfall along the Texas coast in July 2024, was the earliest Atlantic Category 5 hurricane on record, while Hurricane Helene hit the Florida Gulf Coast on Sep. 26 as a Category 4 hurricane, and is considered the deadliest hurricane in the continental U.S. since 2005's Hurricane Katrina.

"As we witnessed last year with significant inland flooding from hurricanes Helene and Debby, the impacts of hurricanes can reach far beyond coastal communities," acting NOAA administrator Laura Grimm said in the statement. "NOAA is critical for the delivery of early and accurate forecasts and warnings, and provides the scientific expertise needed to save lives and property."

In the Pacific, where the hurricane season also runs from June 1 to November 30, activity is forecast to be lower than average in 2025, with NOAA predicting a 30% chance of below-normal storm activity, a 50% chance of normal activity, and only a 20% chance of above-normal activity. Between one and four named storms are predicted in the central Pacific for the season, where a near-normal season has 4 or 5 tropical storms.

A congested atmospheric pattern known as an "omega block" has brought extreme downpours and thunderstorms to parts of the U.S. over the past week, with flood warnings issued Wednesday (May 7) for the southern coasts of Texas, Louisiana and Mississippi.

Abnormally wet and windy weather struck New England Saturday (May 3), The Washington Post reported, and storms rolled over the Rocky Mountains and southern Great Plains Monday (May 5) through Wednesday. While many Eastern, Southern and Western states have experienced adverse weather due to the omega block, conditions in the north-central U.S. have remained mild and clear due to the location of the block.

But what, exactly, is an omega block? And how might it affect weather conditions in the coming days?

An omega block is an atmospheric phenomenon in which a blob of high-pressure air remains trapped between two blobs of low-pressure air for a prolonged period. This sandwich configuration forces weather fronts that usually bring rain from west to east to move up and around the high-pressure area, forming an upside-down U shape that resembles the Greek letter omega. Because weather fronts bring moisture, the ground beneath the two low-pressure areas receives abundant rainfall, but the ground beneath the high-pressure area stays dry.

Related: La Niña is dead — what that means for this year's hurricanes and weather

"In meteorology, blocks are types of pressure patterns that upset the usual eastward progression of our weather," the U.K. Met Office explained in a YouTube video. "The blocks can remain in position for several days, which will lead areas under them to have similar weather for a prolonged period of time."

Currently, a blob of high-pressure air is hovering over the north-central U.S., leading to settled weather conditions and relatively warm temperatures there. By contrast, the East, the West and parts of the South are sitting beneath two blobs of low-pressure air, meaning they are experiencing downpours, thunderstorms and cooler temperatures this week. Omega blocks move very slowly, so these contrasting conditions could last until the weekend and perhaps beyond, meteorologists say.

The role of the jet stream

Omega blocks occur when the jet stream — a fast-flowing air current that usually moves from west to east at an altitude of 5 to 7 miles (8 to 11 kilometers) above Earth's surface — starts to meander like a river. Strong winds within the jet stream may buckle and loop, slowing the current and making areas of low-pressure air closer to Earth's surface migrate unpredictably.

When these migrations happen, the jet stream can steer areas of low-pressure air around an area of high pressure, triggering an omega block. In general, low-pressure air leads to unsettled, cool weather conditions, while high-pressure air leads to more settled and milder conditions.

According to the U.K. Met Office video, a weak jet stream can also lead to another type of block — a "diffluent block" —where a blob of high-pressure air stagnates to the north of a blob of low-pressure air. As with omega blocks, the exact positioning of the high- and low-pressure blobs within a diffluent block determines the type of weather observed at Earth's surface.

Omega and diffluent blocks are most common in the spring but both can persist for several months around midsummer or midwinter, according to the Met Office.

Current forecasts

The current omega block is unlikely to budge before this weekend, and it could stay stuck even longer, an expert told USA Today.

Brian Hurley, a senior meteorologist with the National Weather Service's Weather Prediction Center, told the newspaper that although a temporary breakdown of the omega block could potentially occur, the atmospheric pattern would likely reinstate itself before the weekend and then persist through next week.

It's unclear when the omega block will break down for good, as it would require the jet stream to start flowing smoothly from west to east again, Hurley said. However, "we're not really seeing that now," he said.

There's also a remote chance that a second omega block could appear this week, according to The Washington Post, which would lock in yet more unruly weather.