With their roaring winds, torrential rains and storm surge, hurricanes are one of Mother Nature's most dangerous, and stunning, phenomena. They might be called different names in different parts of the world, but their potential impact is the same, and sometimes devastating. Here, we look at some of the most amazing aspects of hurricanes and see which ones have been the strongest, deadliest and costliest.
The deadliest disaster
The deadliest weather disaster in U.S. history was an unnamed hurricane that struck Galveston, Texas, on Sept. 8, 1900, as a powerful Category 4 storm, with sustained winds of more than 130 mph (209 kph). It killed an estimated 8,000 people.
Same song, different name
Hurricanes, typhoons and tropical cyclones are all the same phenomenon. They're just called different names in different ocean basins. Tropical cyclone is a generic term for storms spawned roughly 300 miles (480 kilometers) north or south of the equator. When they form in the Atlantic or Eastern Pacific and the sustained winds reach 74 mph, the storms are called hurricanes. They are called typhoons in the western North Pacific and cyclones in the South Pacific and Indian Ocean.
Only three Category 5 hurricanes (the highest category on the hurricane strength scale) have hit the United States since the beginning of the 20th century: the 1935 Florida Keys Labor Day Hurricane, Hurricane Camille in 1969, and Hurricane Andrew in 1992.
Hurricane Katrina is the costliest hurricane to have ever hit the United States, causing some $125 billion dollars worth of damage in New Orleans and across much of the Gulf Coast. It was a Category 5 storm at one point, but just Category 3 when it made landfall along the Louisiana-Mississippi border.
The most intense tropical cyclone ever measured when considering a storm's central pressure (this pressure drops as cyclones become stronger) was Typhoon Tip, which on Oct. 12, 1979, had a central pressure of 870 millibars.
The most intense tropical cyclone in terms of the highest wind speeds measured was Tropical Cyclone Olivia, which struck Australia in 1996. It had wind speeds of 253 mph (407 kph) the fastest wind ever measured on the Earth's surface.
Typhoon Tip, in 1979, can boast the record for the largest tropical cyclone on record. Its gale force winds or those above 39 mph (63 kph) extended out for 675 miles (1,110 km) in radius.
Hurricane season in the Atlantic Ocean basin (including the Gulf of Mexico and Caribbean Sea) runs from June 1 through Nov. 30. Well, normally. Read on ...
Hurricanes can form before and after the official, human-imposed start and end dates of the hurricane season. The earliest known hurricane to form in the Atlantic basin was an unnamed one that formed on March 7, 1908.
The latest hurricane to form in the Atlantic basin was the second Hurricane Alice of 1955 on Dec. 31 of that year.
The smallest tropical cyclone on record is 1998's Tropical Storm Marco with gale force winds extending out only 12 miles (19 km).
The most hurricanes ever seen in the Atlantic basin at one time is four. This happened twice: Once on Aug. 22, 1893, and then later from Sept. 25-27, 1998, with Georges, Ivan, Jeanne and Karl.
Since 1970, when worldwide satellite coverage began (and therefore tropical cyclones have been more reliably counted), China has been hit by more tropical cyclones than any other country, according to figures from the U.S. National Hurricane Center. (The United States ranks fifth.)
Forty percent of all hurricanes that hit the United States hit Florida (based on 1851-2009 statistics).
Unfortunate chance of big storms
Eighty-three percent of hurricanes of Category 4 or higher that have hit the United States have hit either Florida or Texas.
The longest-traveling storm in the records was John in the East Pacific basin in 1994. It traveled about 7,165 miles (13,280 km).
The longest-traveling storm in the Atlantic basin was Faith in 1966, which traveled about 6,850 miles (12,700 km).
John was also the longest-lasting storm on record, swirling for 31 days in August and September 1994. (It formed first as a hurricane in the Northeast Pacific, then moved to the Northwest Pacific and was renamed as a typhoon.)
Category 5 status (with winds greater than 157 mph, or 252 kph) is hard for tropical cyclones to maintain. The longest lasting Cat 5 was Nancy in the West Pacific in 1961. It stayed that strong for five days.
The most named storms (those that achieve tropical storm status or higher) ever to form in one season in the Atlantic basin was 28 during the 2005 season. Because the National Hurricane Center uses names from the alphabet for storms (and not every letter is represented) it ran out of names that year. The last six storms (following Hurricane Wilma) were named Alpha, Beta, Gamma, Delta, Epsilon and finally, Tropical Storm Zeta, which formed Dec. 30 and lasted until Jan. 6, 2006. One of the 28 storms was a subtropical storm.
Hectic, even for hurricane season
2005 also saw the most hurricanes ever to form in a single Atlantic season, with 15.
Calm, for a change
The fewest named storms ever to form in the Atlantic basin was four in the 1983 season.
Warm water is the fuel that drives a hurricane. Hurricanes require ocean water temperatures of at least 80 degrees Fahrenheit (27 degrees Celsius) to form. Above this temperature the atmosphere is unstable, and that allows deep convection, the overturning of air that allows a tropical storm to become a hurricane, to occur. Below that temperature, the atmosphere is too stable and not enough energy is introduced into the storm.
Six year cycle
Hurricane names are determined by the World Meteorological Organization headquartered in Geneva. The WMO is in charge of updating the six weather regions of the world (the United States is in region four, which consists of North America, Central America and the Caribbean). Names are reused every six years, but names of the most significant storms like Andrew and Katrina are retired.
Originally, hurricanes were given the names of saints who were honored on the day the storm occurred, according to the National Oceanic and Atmospheric Administration. For example, the hurricane that hit Okeechobee, Florida, in 1928, was alternately called the Okeechobee hurricane and the San Felipe Segundo hurricane because it hit on the feast day of Saint Philip.
Tropical cyclones' winds rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere because of the Earth's Coriolis force. Convection is most intense near the storm center, and so air rises. Air is drawn into the center of the storm along the surface, and that creates wind. Because Earth is rotating under the storm, the winds are curved.
In the Atlantic Ocean basin, hurricane activity historically peaks around Sept. 10.
When the National Hurricane Center began giving official name to storms, in 1953, they were originally all female.
Males names were added to the hurricane name lists in 1979. Current lists alternate between male and female names.
Supply and demand
Current Atlantic storm name lists exclude the letters Q, U, X, Y and Z because there are not enough names starting with these letters to include them.
When a name is retired from the list, another name of that same letter and gender replaces it. For example, 2011's Irene was retired and replaced by Irma.
Up for retirement
76 hurricane names have been retired off the naming list. The most recent is 2011's Irene.
El Niño effects
El Niño events tend to dampen Atlantic Basin hurricane formation by sending energy from the Pacific Ocean, in the form of high-altitude winds, all the way over to the Atlantic, where the winds tend to sheer the tops off some developing storms. La Niña events tend to bolster Atlantic hurricane formation.
Tropical cyclones are very rare in the South Atlantic Ocean because atmospheric conditions there aren't conducive to their formation. A hurricane did form there in 2004 and made landfall in Brazil.
Historical cyclone tracks
While the East Coast of the United States sees many hits by tropical storms and hurricanes, those landfalls are rare on the West Coast. This is because storms that form in the tropical and subtropical latitudes tend to move to the west-northwest in the Atlantic, this takes them toward the United States; in the Pacific, this takes them away from it. Water temperatures off the West Coast are also typically too cool to form and sustain tropical cyclones, as opposed to the warm waters of the Gulf Stream and Gulf of Mexico.
Tropical Storm Beryl in 2012 was the earliest second named storm of any season since record keeping began in 1950. It formed on May 25th.
Hurricane Katrina, which hit in 2005, was the deadliest hurricane to strike the United States since the Palm Beach-Lake Okeechobee hurricane of September 1928. Katrina killed 1,800 people, while the Okeechobee hurricane killed 1,836 in the United States, 312 in Puerto Rico and 18 in the Bahamas.
13. Strange damage
The 10 costliest hurricanes in U.S. history have all occurred since 1992. With the exception of Hurricane Andrew in 1992, they have all occurred since 2001. Costs have risen in part because more people and more structures occupy coastal locations.
In 1979, Tropical Storm Claudette dropped excessive amounts of rain over parts of Texas and Louisiana. An observer west of Alvin, Texas, reported 43 inches (109 centimeters) in 24 hours, which is a United States record for a 24-hour rainfall amount. The storm total at that location was 45 inches (114 cm).
The longest gap between U.S. hurricane landfalls has been three years. This happened between Hurricane Ike in September 2008 and Hurricane Irene in August 2011 and between Hurricane Irene in October 1999 and Hurricane Lili in October 2002.
Most deadly hurricane
Based on historical data available, The Great Hurricane of 1780 was the deadliest Atlantic basin storm from the period of 1492 onward, according to a National Hurricane Center study. It is estimated to have killed 22,000 people across the Caribbean.
An average Atlantic hurricane season produces 11 named storms, six hurricanes and two major hurricanes.
Hurricane Kate in 1985 was the latest hurricane to strike the United States. It made landfall on Nov. 21.
When Tropical Storm Debby formed on June 23, 2012, it marked the first time the Atlantic basin saw four named storms before July 1 since record keeping began in 1851.
The deadliest and costliest hurricane to ever hit Hawaii (in modern times) was Hurricane Iniki, which struck on Sept. 12, 1992 and caused about $3 billion in damage adjusted for inflation. The storm killed four people and affected 14,000 homes, according to the Weather Channel.
Safer waters, considering
Only four hurricanes have made direct hits on Hawaii in the last 60 years, according to the Weather Channel: Nina in 1957, Dot in 1959, Iwa in 1982 and Iniki in 1992.
Hurricanes and other tropical cyclones reach Category 3 wind speeds (between 111 and 129 mph, or 178 and 208 kph) nearly nine hours earlier than they did 25 years ago, a 2012 study in the journal Geophysical Research Letters found.
2010 was the first year since 1900 that saw 10 or more hurricanes develop without one hitting the United States.
Historically, one in four Atlantic hurricanes strikes the United States as a hurricane.