Storm Surge and
The Saffir-Simpson Hurricane Scale

Sea Level

Storm Surge
An abnormal rise of sea along a shore as the result, primarily, of the winds from a storm.
Category 1: Minimal Damage
Winds 74-95 mph
Surge: 4 to 5 feet

No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Also, some coastal road flooding and minor pier damage.
Category 2: Moderate Damage
Winds 96-110 mph
Surge: 6 to 8 feet

Some roofing material, door, and window damage of 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.
Category 3: Extensive Damage Winds
111-130 mph
Surge: 9 to 12 feet

Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. 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.
Category 4: Extreme Damage Winds
131-155 mph
Surge: 13 to 18 feet

More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and 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
Surge: higher than 18 feet

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 within 5-10 miles (8-16 km) of the shoreline may be required. These surge values are averages for these storm categories. Actual surge depths may be much greater.

Graphics and text courtesy of the South Carolina Emergency Management Division.

« this page last modified 06/02/04 »