As air warmed and moistened by the sea rises, it whirls into a vortex often hundreds of miles across. Perhaps only a third of the hurricanes that form will actually strike land. Hurricane winds can be violently destructive. Winds go even higher for category 5 hurricanes, which are extremely rare. Hurricane winds can whip up waves of 50 feet or higher in the open sea.
Convection creates an area of low pressure in the center of the vortex.
Storm surges are greatest on the right front side of the hurricane in the Northern hemisphere as water is pushed ahead of the storm. Severe storm surges can deliver a 20-foot or greater rise in sea level and when this is combined with a high lunar tide and the pounding of enormous waves, the damage can be devastating. A key to saving the human lives at risk in hurricanes is accurate, timely warning and evacuation. The Galveston hurricane of 1900 killed some 6,000 people largely because there was no warning system. The U.S. National Weather Service and related NOAA agencies have made enormous strides in measuring, understanding, and predicting hurricanes in recent decades leading to much more effective warnings.