Hurricanes

What is a hurricane?



  Hurricanes are part of a family of weather systems known as \"tropical cyclones.\" The word hurricane is from the West Indian word hurricane, meaning \"big wind.\" A hurricane begins its life as a disorganized storm system, which forms over warm, tropical waters in the Atlantic. When the storm system become more organized, it is classified as a \"tropical depression,\" and given a number by the National Hurricane Center. If the winds in a tropical depression grow in intensity to 40mph, it is re- classified as a \"tropical storm,\" and it receives a name. When the winds in the storm reach 75mph (120kph), the storm is upgraded to a hurricane.

The winds of a hurricane are structured around a central \"eye\", which is an area that is free of clouds and relatively calm. Around this \"eye\" area, storm clouds wrap in a counter-clockwise motion. This \"eyewall\" of clouds, wind and rain, is the most destructive part of the storm. In fact, it is the eyewall that creates the eye, since the rapid spinning clouds in the wall reduce the pressure in the eye and suck out any clouds that may be there.

Hurricanes are usually compact storms, with maximum wind velocities extending out 10 to 100km from the eye. Of course, one can still experience gale-force winds as much as 300 miles out from the eye, which is why everyone in the Gulf Coast area is concerned when a hurricane comes a-calling.



How do hurricanes form?



  A hurricane starts out as an ordinary storm over warm ocean waters. But it absorbs heat and water from the ocean below, it grows bigger and bigger. An average hurricane is about 600 km (375 mi.) across. That’s the distance from New York City to Norfolk, Virginia.

 

  The huge, spiraling storm slowly starts to move carried westward by the prevailing in the region. At sea, boats are tossed around like toys. If the hurricane hit land it can destroy whole communities. Violent...