Hurricane again

A swirling powerful storm that is formed over a warm sea is called a hurricane. Hurricanes can cause significant amounts of damage to anything in its path through fierce winds, torrential rains, flooding, and its huge waves crashing ashore.
Hurricanes can kill more people and destroy more property than every other natural disaster.
The calm central where the winds of the hurricane swirl around is called the eye. The eye is surrounded by a band of dark, tall clouds called the eyewall. The eye is serene as it is free of large clouds an rain. The eye is usually between 10 and 20 miles in diameter.
The strongest winds in the hurricane's eyewall are caused by the large changes in pressure.

http://physicsofhurricanes.homestead.com/index.html