First, You have to realize that a number of conditions must be in place for a hurricane to form.
Ocean Temperature: The ocean must be at least 80 degrees F to a depth of 150 feet.
High humidity: There must be relatively high humidity in the middle of the troposphere (the lowest layer of the earth's atmosphere).
Winds: The difference in wind speed between the upper and lower levels of the troposphere cannot be more than about 20 mph.
Thunderstorms: A weakly organized thunderstorm system must be present to generate spin and the inflow of air.
After this, now we get warm, humid, ocean-heated air rises and creates a low-pressure area.
Around the core of the storm system, winds speed up and begin to spiral inward. As air pressure drops, more air is sucked in, and wind velocity rises.
Wind speeds reach at least 74 mph and the storm system forms a vortex, or 'eye.' A hurricane is born...
Now, I didn't do this off the top of my head. I typed it all out off the page I got it from. MSNBC interactive...if you go there, you get the cool graphics that kept me entertained for about 5 minutes.