What is a Storm Surge?
A Storm surge is simply water that is pushed toward the shore by the force of the winds swirling around the storm, most commonly associated with hurricanes. The storm surge is the most deadly aspect of a hurricane, responsible for 90% of deaths during hurricanes, but remember that storm surges are different from tidal surges.
The level of the surge in some areas vary due to the slope of the continental shelf. With a steep continental shelf we don’t see as much surge inundation. Although if you are in a shallow slope it will allow a much greater surge to come onto the coastal line & can cause a large amount of damage to the communities that are in the path of the storm surge.
There is a growing concern in areas such as the United States’ Gulf Coast region about the lack of public storm surge awareness. Since the United States has not been hit dramatically by storm surges since the 1920s, most of the public is unaware of the true dangers of this phenomena. With the growing frequency of hurricanes in this region of the world there is a push to teach awareness and preparedness before storms like the 1900 Galveston hurricane storm surge, which killed over ten thousand people.
One tool used to evaluate the threat from storm surge is the SLOSH model. Emergency managers use this data from SLOSH to determine which areas must be evacuated for storm surge. The problem is always the uncertainty about how intense the storm will be when it finally reaches land. Emergency managers and local officials balance that uncertainty with the human and economic risks to their community. This is why a rule of thumb for emergency managers is to plan for a storm one category higher than what is foretasted. This is a reasonable precaution to help minimize the loss of life from hurricanes.
Winds: 74-95 mph
Along the South Carolina coast, surges of up
to 4 to 5 feet can be expected.
No real damage to building structure. Damage primarily to unanchored mobile homes, shrubbery, and trees. Also, some coastal road flooding and minor pier damage.
Winds: 96-110 mph
Along the South Carolina coast, surges of
up to 6 to 8 feet can be expected.
Some roofing material, door, and window damage to buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Small craft in unprotected anchorages break moorings.
Winds: 111-130 mph
Along the South Carolina coast, surges of
up to 9 to 12 feet can be expected.
Some structural damage to small residences and utility buildings with a minor amount of curtain wall failure. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Flooding near the coast destroys smaller structures with larger structures damaged by battering of floating debris.
Winds: 131-155 mph
Along the South Carolina coast, surges of
up to 13 to 18 feet can be expected.
More extensive curtain wall failures with some complete roof structure failures on small residences. Shrubs, trees and most signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Major damage to lower floors of structures near the shore.
Category 5: Catastrophic Damage
Winds: More than 155 mph
Along the South Carolina coast, a surge higher
than 18 feet can be expected.
Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. Most shrubs, trees, and signs blown down. Complete destruction of mobile homes. Severe and extensive window and door damage. Massive evacuation of residential areas on low ground may be required.
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