
Hurricanes
Hurricanes are what scientists call "strong tropical cyclones." They're a large, rotating system of clouds, wind and thunderstorm activity that wreaks havoc wherever it goes. Get the goods on one of the most damaging and deadliest natural disasters of the world.
What is a Hurricane?
A hurricane, tropical cyclone, or typhoon is a
severe tropical storm that forms in the Atlantic Ocean, Caribbean Sea, Gulf of
Mexico or Pacific Ocean. When large areas of the
ocean become heated, the air pressure over that area drops, causing
thunderstorms, incredible
waves and violent winds that start at 74 mph. Hurricanes rotate in a
counter-clockwise direction around an "eye." When they come onto land, the torrential rains, winds and waves can
damage buildings, trees and cars. In the US, the official Atlantic hurricane season is from June 1 to November 30, and the Pacific hurricane season runs from May 15 to November 30. However, hurricanes can
happen at any time of the year.
Hurricane Classification
Based on their
wind speeds and damage potential, hurricanes are ranked according to the
Saffir-Simpson Hurricane Scale. It starts at one (lowest winds) and goes up to five (highest winds).
Category One - 74-95 mph winds.
Category Two - 96-110 mph winds.
Category Three - 111-130 mph winds.
Category Four - 131-155 mph winds.
Category Five - Winds greater than 155 mph.
The Naming Process
A tropical storm is given a name once its winds reach
40 mph. In keeping with the
English practice of referring to inanimate objects (like cars and boats) as female, hurricanes were
named after girls. The first storm of the year was assigned a name beginning with the letter "A," the second with a "B" and so on. However, guys'
names were introduced in 1979 and now, the names are
alternated. Some hurricanes names are Andrew, Fran and Hugo.
Hurricane Katrina
On August 24, 2005, a Category One hurricane formed in the Atlantic Ocean and hit Miami, FL, causing
major flooding, loss of
power to more than one million residents, and 11 deaths. This hurricane, named Katrina, later became a Category 5, with winds of
175 mph, and hit Lousiana, Mississippi, Alabama, Georgia, Tennessee, Kentucky and may even reach parts of Canada. Nearly 2,000 people died as cities were
flooded, buildings were destroyed and hundreds of thousands of residents were forced to
flee their homes. Hurricane Katrina was one of the four
fiercest US storms ever seen.
Terms to Know
Hurricane Watch - A hurricane is possible within 36 hours. You should stay tuned to the radio or television for more information.
Hurricane Warning - A hurricane with winds of 74 mph is expected within 24 hours. You may have to prepare to evacuate your home.
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Tornadoes
Tsunamis
Earthquakes
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Read more: Our Planet