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What is a Hurricane?

Sep 20, 2018

With the current Hurricanes hitting the US, it’s hard to open the paper without seeing some hurricane news, so it’s a good idea to get to know exactly what a hurricane is. 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 world’s most deadly natural occurrences in All About Hurricanes.

This is what a Hurricane looks like from aboveThis is what a Hurricane looks like from aboveCourtesy of the Museum of the City of New York

What happens in 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 parts of the ocean become heated, the air pressure over that area drops, causing thunderstorms, incredible waves and violent winds that start at 74 mph (miles per hour). 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.

Hurricane Classification ChartHurricane Classification Chart

The Naming Process

A tropical storm is given a name once its winds reach 40 mph. Originally hurricanes were only given girls’ names (like Sandy, or Katrina). The first storm of the year was assigned a name beginning with the letter "A," the second with a "B" and so on. However, boys names were introduced in 1979 and now, the names are alternated. Some male hurricane names in the past have been Andrew and Hugo.

American Hurricanes: Sandy, Katrina and Harvey

The most recent hurricane to hit American shores was Hurricane Sandy. Sandy was the largest Atlantic Hurricane on record. It was the tenth Hurricane to happen in the 2012 Atlantic Hurricane season. It was formed on October 22nd, 2012 and had completely dissipated by October 31st. Sandy devastated portions of the Caribbean, the Mid-Atlantic and the Northeastern United States. The total people who died because of Sandy so far is 191. Sandy started out as a tropical wave in the western Caribbean, but resurfaced as a powerful Category Two Hurricane and took roofs off houses in Jamaica and left 70% of residents without electricity.

Hurricane Sandy, Ocean Grove Pier, N.J.Hurricane Sandy, Ocean Grove Pier, N.J.

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 Louisiana, Mississippi, Alabama, Georgia, Tennessee, and Kentucky. 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.

Hurricane Harvey hit Texas landfall as a Category 4 hurricane on the night of Friday August 25th, 2017 and is the strongest hurricane to hit the U.S. in more than a decade. Hurricane Harvey is an active tropical cyclone that is causing unprecedented and catastrophic flooding in southeastern Texas, and was the first major hurricane to make landfall in the United States since Wilma in 2005. Harvey caused at least 71 confirmed deaths; 1 in Guyana, and 70 in the United States. Harvey is being called the worst disaster in Texas history, and expected the recovery to take many years.

An Interstate highway submerged from the effects of Hurricane Harvey seen during widespread floodingAn Interstate highway submerged from the effects of Hurricane Harvey seen during widespread flooding

Hurricane Irma

Hurricane Irma developed on August 30th, 2017 and was an extremely powerful and rare Cape Verde type hurricane; the most intense observed in the Atlantic in over a decade. It was also the most intense hurricane to strike the United States since Katrina in 2005, and the first major hurricane to hit the state of Florida since Wilma in 2005.  Irma caused widespread and catastrophic damage throughout its long lifetime, particularly in parts of the northeastern Caribbean.

The storm caused catastrophic damage in Barbuda, Saint Barthélemy, Saint Martin, Anguilla and the Virgin Islands as a Category 5 hurricane.  As of September 12, the hurricane has caused at least 49 deaths (one in Anguilla, one in Barbados, three in Barbuda, 10 in Cuba, 11 in the French West Indies, one in Haiti, three in Puerto Rico, four on the Dutch side of Sint Maarten, 11 in the United States, and four in the U.S. Virgin Islands.

Hurricane Florence

Hurricane Florence was a powerful and long-lived Cape Verde hurricane that caused severe and extensive damage in the the Carolinas in September 2018. Florence originated from a strong tropical wave that emerged off the west coast of Africa on August 30, 2018. Despite making landfall as a weakened Category 1 hurricane, Florence still had enough wind speed to uproot trees and cause widespread power outages throughout the Carolinas. At least 40 people have died as a result of the Hurricane. 

Important Terms

  • 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.
Have Your Say

Have you ever experienced a Hurricane? Let us know in the comments section below.