Storm surge is the deadliest and most destructive feature of coastal storms. Often, 90% of deaths in hurricanes can be attributed to storm surge. It is defined as the rise in water level above the mean tidal level.
Storm surge is caused by the abnormally low pressure, high winds, and high waves associated with coastal cyclones, and results in significant flooding and erosion. The surge can wreck homes, and pull boats and cars inland or out to sea. Coastal towns near large bays or areas with shallow water are the most susceptible to damage by storm surge. A 28-foot storm surge in Gulfport, Mississippi as Hurricane Katrina makes landfall. The sustained winds of the storm can push an enormous amount of water toward the shoreline, resulting in a piling up of the water toward the coast. Referred to as ”storm surge,” this elevated water level is enhanced by the negative pressure effect of the cyclonic low, causing the water to rise beneath it.
If the storm encounters a shallow continental shelf, the surge can push farther inland. The combination of the storm surge and high tide can result in a surge that exceeds the normal high tide, known as a “storm tide,” which can lead to severe coastal flooding well inland. With some storm surges reaching heights of 15 (or 30?) feet, the dense population along the Atlantic coast is especially at risk since many of these coastlines are less than 10 feet above sea level.
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