According to LiveScience, the three most common causes of a hurricane's deterioration are a lack of water, a drop in water temperature or wind shear. Hurricanes require a steady stream of warmth provided by warm ocean waters to maintain their power. Once they lose it, they deteriorate quickly.
Hurricanes form when warm ocean waters heat the air above the surface. This causes evaporation of sea water into the atmosphere, which sets up the convection currents and rotation that fuel a hurricane. Over land or over cooler water, the hurricane's engine begins to lose power. In addition, areas of strong wind shear can disrupt the rotation and current, which causes the hurricane to die prematurely.