This is a type of tropical cyclone that includes severe thunderstorms and wind speeds of 74 miles per hour or more. The wind speed is the key in determining if the weather system is a hurricane, a tropical storm or tropical depression.  

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Hurricanes form with the help of warm water and a high level of moisture in the atmosphere. The warm water heats the air as low pressure winds form in the center, and allows for thunderstorms to form as the warm air rises due to the heat. As hurricanes move north, and thus over larger landmasses, they lose their source of energy — warm water — and slowly dissipate.
Hurricanes in the western hemisphere are named on a rotating male-female basis, with the names of particularly devastating hurricanes retired from future lists. Naming hurricanes came about to assist in both tracking hurricanes, especially in the case of multiple storms, but also easily relaying information to the public.
In the event of a hurricane, putting shutters over the windows, clearing the yard of any furniture that may be blown into the home and preparing a supply of water are all necessary steps. If an evacuation order has been declared, follow it. A hurricane preparedness brochure from the state or local government should have more details on this.
(Text by Noel Kirkpatrick

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