Transcript for Anatomy of a Hurricane, segment 02 of 5

Hurricanes are beautifully organized storms of destruction, part of a family of storms called tropical cyclones. Those impacting the United States typically develop between June and late November just north of the equator in the tropical to subtropical waters of the Pacific Ocean, the Gulf of Mexico, the Caribbean Sea, and the Atlantic Ocean.


While some mystery surrounds the exact origins of hurricanes, tropical disturbances such as clusters of thunderstorms accelerate the process by generating a column of rising air and a zone of low pressure. Pushed by the tradewinds, the disturbance becomes a spinning mass of thunderclouds, growing as warm, moist air sweeps in to the low-pressure void. Due to the Earth's Coreolis Effect, the cloud mass always rotates counterclockwise in the northern hemisphere. As wind speeds exceed seventy-four miles per hour, a hurricane is born. Hurricanes vary in intensity from a Category One hurricane with winds between seventy-four and ninety-five miles per hour up to a Category Five hurricane with winds greater than one hundred fifty-five miles per hour.

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