Hurricanes are products of the tropical ocean and atmosphere. Powered by heat from the sea, they are steered by the easterly trade winds and the temperate westerlies as well as by their own ferocious energy. Around their core, winds grow with great velocity, generating violent seas. Moving ashore, they sweep the ocean inward while spawning tornadoes and producing torrential rains and floods. In the Atlantic, Caribbean, and Gulf of Mexico, hurricane development starts in June. For the US the peak hurricane threat exists from mid-August to late October with the season officially ending November 30th. Hurricane winds can exceed 155 mph and severely affect areas hundreds of miles inland. It is the wind and low pressure that create the storm surge.
A storm surge is a great dome of water often 50 miles wide, that comes sweeping across the coastline near the area where the eye of the hurricane makes landfall. The surge, aided by the hammering effect of breaking waves, acts like a giant bulldozer sweeping everything in its path. The stronger the hurricane and the shallower the offshore water, the higher the storm surge will be. If the storm surge arrives at the same time as the high tide, the water height will be even greater. This is unquestionably the most dangerous part of a hurricane. Nine out of ten hurricane fatalities are caused by the storm surge. Hurricane Camille in 1969 produced a 25 foot storm surge which inundated Pass Christian, Mississippi.
Landfall is the term used to indicate the moment a hurricane hits land. When a hurricane hits at a speed of 74 mph, the transaction of energy within its circulation is great. The condensation heat energy released by a hurricane in one day can be the equivalent of energy released by fusion of four hundred 20-megaton hydrogen bombs.
Perception of Risk - Over the past several years, the warning systems have provided adequate time for people on the barrier islands and coastline communities to move inland when hurricanes threaten. However, it is becoming more difficult to evacuate people from these areas because roads have not kept pace with the rapid population growth. There are 45 million permanent residents along the hurricane-prone coastline. In addition to these permanent residents, the holiday, weekend, and vacation populations swell some coastal areas 10-100 fold. The problem is further compounded by the fact that 80 to 90% of the population now living in hurricane-prone areas have not ever experienced the core of a "major hurricane." Many have been through weaker storms. The result is a false impression of a hurricane's damage potential. This often leads to complacency and delayed actions.