While waves are directly influenced by wind, their effect is distinct from the currents influenced by wind in a storm. Although these surface waves are only responsible for a small amount of water transport in open water, they may be responsible for a significant amount of transport close to the shore. Powerful wind whips up large, powerful waves in the direction of its movement.
A lot of water is carried along the shore when waves break in a line that is almost parallel to the beach. The water moving toward the shore as they break has a lot of momentum and may run up a sloping beach to an elevation above the mean water line, possibly twice as high as the wave before breaking.
Estuaries experience the majority of the rainfall effect. Over large areas, hurricanes can dump as much as 12 inches (300 millimeters) of rain in 24 hours, with higher rainfall densities in localized areas. Surface runoff can therefore rapidly flood rivers and streams. As storm-driven ocean waters meet rainfall flowing downstream into the estuary, this can raise the water level near the head of tidal estuaries.
The flow of water over the underlying topography, i.e. the shape and depth of the ocean floor and coastal area, also has an impact on storm surge and wave heights on shore. A narrow shelf with deep water close to the shoreline typically produces waves that are higher and more powerful but have a lower surge. With shallower water and a wider shelf, storm surge tends to be higher with smaller waves.
For instance, the water depth in Palm Beach, which is located on the southeast coast of Florida, is 91 meters (299 feet) offshore and 180 meters (590 feet) seven kilometers (4.3 miles) out. This is quite deep and steep; The waves are larger than those on the west coast of Florida, but the storm surge is not as high.