The storm surge is enhanced by the fact that the storm and winds are both moving in the same general direction. As a result the water is pushed by the wind onto the land surface. The storm surge is often the most destructive aspect of a hurricane that reaches land. The strength of hurricanes is determined using a scale based on wind velocity, surface pressure, and height of storm surge. The Saffir-Simpson Scale is shown below.
Most hurricanes are in the lower categories.
The category V hurricanes are the strongest. In practice, the sustained winds are usually used to classify a hurricane with this scale. Dissipation of Hurricanes Recall that the source of energy for a hurricane is latent heat. This is provided by the warm ocean water. If a hurricane moves into colder waters, the latent heat source is greatly diminished, and they begin to dissipate.