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.

     Tropical Depression       (20-34kts and a "closed" circulation)
     Tropical Storm (named)    (35-64kts)
     Hurricane                 (65+kts or 74+mph)

Saffir-Simpson Scale

     Category 1    65- 82 kts;  74- 95 mph;    >980 mb;      >28.94 "Hg
     Category 2    83- 95 kts;  96-110 mph; 965-979 mb; 28.50-28.91 "Hg
     Category 3    96-113 kts; 111-130 mph; 945-964 mb; 27.91-28.47 "Hg
     Category 4   114-135 kts; 131-155 mph; 920-944 mb; 27.17-27.88 "Hg
     Category 5      >135 kts;    >155 mph; 919     mb; 27.16       "Hg

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Some other hurricane pages

Note: any people who wants a link here and has a banner, send me an email with the banner and I will add it.
Casi Tropical
Hurricane City

Some Important Dates

6 August: Dr. William Gray's August Tropical Prediction
Mid-August: Cape Verde season begins, most active period of season begins
24 August: Anniversary of Hurricane Andrew
10 September: Peak of hurricane season
21 September: Anniversary of Hurricane Hugo
Late September: Cape Verde season ends
Early October: Most active part of season ends
30 November: Hurricane Season ends
4 December: prediction by Dr. William Gray