Nasa's Earth Observatory Website (http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3) has an interesting look at water temperatures in the Gulf and how they are the motivating force in Hurricane development. I'm not sure how long the link will remain valid as the content changes occasionally, but the pictures and explanations you can find here are always interesting and enlightening. Here is a bit of what they say about it:
A hurricane’s track depends primarily on the winds that steer it, and these winds are forecasted with atmospheric models. The hurricane’s energy source, however, comes from the ocean.
Sea surface height is a useful measure of potential hurricane activity because storm-fueling warm water is higher than surrounding cooler water. The area shown in red is approximately 35 to 60 centimeters (roughly 13 to 23 inches) higher than the surrounding Gulf.