Erica's Answer:
This is due in part to prolonged cloud cover over the ocean water, but the greater influence is from an event called upwelling. This is when colder water deep below the ocean's surface is drawn toward the top, where the water tends to be warmer in the summer. Upwelling happens in hurricane track areas because the winds in a hurricane cause lots of wave action. It's kind of like stirring the water below. The cooler water in the hurricane's wake is not conducive to hurricane development and strengthening. So, any new hurricanes that move into that area will naturally start heading away from the cooler water, toward warmer water on the other side of the previous hurricane's track. A possible example is in 2005, when Hurricane Rita was taking a very similar track to Hurricane Katrina until it hit the cooler water in Katrina's wake. This might have caused the storm to move further west into relatively warm water, which in turn made Rita deliver a much stronger hit to the Houston area than to New Orleans.- Erica
