Hurricane Irma: Everything You Need to Know About This Monster Storm

To help you stay on top of the storm's development, Live Science has compiled everything you need to know, from tips on hurricane preparedness to Irma's latest forecasts and impacts, to the science behind nature's biggest hurricanes.

Live updates

As of 2 p.m. ET, Monday, Sept. 11:

Irma, with sustained winds of up to 60 mph (95 km/h), is slowly weakening as it moves into southern Georgia, according to the National Hurricane Center. The storm is about 50 miles (80 kilometers) south-southeast of Albany, Georgia, and about 55 miles (85 km) east of Tallahassee, Florida. The storm is now moving in the north-northwest direction at 17 mph (28 km/h) — a motion expected to continue through Tuesday (Sept. 12).

The center of the storm is forecast to continue moving over southwestern Georgia today, before moving into eastern Alabama Tuesday morning. Irma is expected to become a tropical depression (meaning maximum sustained winds below 39 mph, or 63 km/h) on Tuesday.  

Storm surge in Florida remains a threat. "The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooding by rising waters moving inland from the shoreline," the NHC said. 

These areas should expect to see the following water levels if surge happens at high tide:

  • Clearwater Beach to Ochlockonee River: 4 to 6 feet
  • Tampa Bay: 2 to 4 feet
  • Anna Maria Island southward to Bonita Beach: 1 to 3 feet
  • South Santee River to Fernandina Beach: 4 to 6 feet
  • Fernandina Beach to Flagler/Volusia County line, including the St. Johns River: 3 to 5 feet

A Twitter List by jeannabryner

Where will Hurricane Irma make landfall?

Hurricane Irma made landfall in the Caribbean in the early morning hours of Wednesday, Sept. 6. The storm's core passed over parts of the U.S. Virgin Islands late Wednesday afternoon. On Wednesday, Irma wreaked havoc on the Caribbean island of Barbuda, leveling 95 percent of its buildings and leaving the island "barely visible," according to the New York Times. Barbuda's sister island Antigua was somewhat unscathed, according to the Times. The then-Category 5 hurricane skirted Puerto Rico, Haiti and the Dominican Republic, though it slammed into the Turks and Caicos on Thursday (Sept. 7) evening.

Irma is starting to move slowly away from the coast of Cuba, and South Florida was already showing deteriorating weather on Saturday (Sept. 9), the NHC said. On Saturday night (Sept. 9), Irma lashed the Keys with strong winds, storm surge and crashing waves. It made landfall at 9:10 a.m. EDT on Sunday at Cudjoe Key, about 20 miles (32 km) northeast of Key West; As Irma passed over the Keys on Sunday morning, a wind gust of 120 mph (195 km/h) was reported at the National Key Deer Refuge on Big Pine Key. Now, the storm is heading north right around Ft. Myers. [Get the latest updates from the National Hurricane Center]

Florida Gov. Rick Scott and Puerto Rico Gov. Ricardo Rosselló declared states of emergency in response to the storm.

The U.S. Air Force's Hurricane Hunters are flying into the eye of Irma, coming out with amazing images and footage of the most powerful parts of the storm.  

And Irma isn't alone. There are two other storms brewing in Irma's wake: Jose is churning in the Atlantic and Katia is gaining strength in the southern Gulf of Mexico. Both storms strengthened into hurricanes on Wednesday (Sept. 6), according to the National Hurricane Center.

How big is Hurricane Irma?

Irma was upgraded to a Category 5 hurricane early on Sept. 5, and quickly became the strongest hurricane on record to ever form in the Atlantic Ocean, not including the Caribbean basin or the Gulf of Mexico, according to the National Hurricane Center. A Category 5 storm on the Saffir-Simpson scale is defined as one that has maximum sustained winds of 157 mph (253 km/h) or higher. [Read more: Hurricane Irma Now a Category 5 Storm: What That Means]

The ferocious winds that Hurricane Irma is packing are expected to create serious storm surges along its path. However, the extent of threat from such storm surge depends on where the hurricane goes (a track that is still uncertain) and features of the coast and seafloor. 

The Saffir-Simpson scale only goes up to Category 5, but technically, there is no limit to how strong a hurricane can get.

How to prepare for a hurricane

Here are several ways you can prepare for a hurricane:

  • Start with a plan
  • Prepare your home
  • Buy emergency supplies, including a flashlight, extra batteries, a first aid kit, emergency food and water, sturdy shoes and essential medicines.

Read more about how to build an emergency preparedness kit.

What to expect from hurricane season 2017

Officially, the Atlantic hurricane season begins on June 1 and runs until Nov. 30. In the eastern Pacific Ocean, hurricane season begins May 15 and ends Nov. 30. On both coasts, these storms typically peak between August and October. The Climate Prediction Center predicted this year's hurricane season would be extra active, with a forecast of between 14 and 19 named storms, or those with sustained winds of at least 39 mph (62 km/h), and between two and five major hurricanes with sustained windspeeds of at least 111 mph (178 km/h).

Original article on Live Science.

Jeanna Bryner
Live Science Editor-in-Chief

Jeanna served as editor-in-chief of Live Science. Previously, she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species. She also received an ocean sciences journalism fellowship from Woods Hole Oceanographic Institution.