The wind speed is a determining factor in helping estimate a hurricane’s intensity. The Saffir-Simpson Hurricane Scale is a 1 to 5 rating, which is used to give an estimate of the potential property damage and flooding expected along the coast.
Saffir-Simpson Hurricane Wind Scale modification: Effective May 15, 2012, a minor modification of the Saffir-Simpson Hurricane Wind Scale (SSHWS) will be made to resolve rounding issues associated with the conversion of units from knots to mph which are used for wind speed.
Category 4 on the SSHWS will be broadened by one mph at each end of the range, yielding a new range of 130-156 mph. This will also result in a minor modification of the Category 3 and 5 wind speed thresholds. The SSHWS will change as follows:
From:
Category 3: 111-130 mph (96-113 kt, 178-209 km/h)
Category 4: 131-155 mph (114-135 kt, 210-249 km/h)
Category 5: 156 mph or higher (136 kt or higher, 250 km/h or higher)
To:
Category 3: 111-129 mph (96-112 kt, 178-208 km/h)
Category 4: 130-156 mph (113-136 kt, 209-251 km/h)
Category 5: 157 mph or higher (137 kt or higher, 252 km/h or higher)
There will be no change to the wind speeds currently assigned to Categories 1 and 2.
 Category One: winds between 74 and 95 miles per hour. Storm surge generally 4 to 5 feet above normal. No real damage to building structures. Some damage to trees and poorly constructed houses. Some road flooding and minor pier damage may occur.
Category Two: winds between 96 and 110 miles per hour. Storm surge generally 6 to 8 feet above normal. Considerable damage to shrubbery and trees, with some trees blown down. Some roofing material, door, and window damage of buildings. Coastal and low lying escape routes flood 2 to 4 hours before arrival of the eye of the hurricane.
Category Three: (updated) winds between 111 and 129 miles per hour (96-112 kt, 178-208 km/h). Storm surge generally 9 to 12 feet above normal. Some structural damage to small residences and buildings. Damage to large trees, foliage blown down. Mobile and poorly constructed signs destroyed. Low-lying escape routes are cut by rising water 3 to 5 hours before arrival of the hurricane eye. Flooding near the coast may destroy smaller structures with larger structural damage by battering of floating debris. Evacuation of residences near the shoreline may be required.
Category Four: (updated) winds between 130 and 156 miles per hour (113-136 kt, 209-251 km/h). Storm surge generally 13 to 18 feet above normal. Shrubs, trees, and signs may be blown down. Extensive damage to doors and windows. Major damage to lower floors of structures near the shore. Terrain lower than 10 feet above sea level may be flooded, requiring massive evacuation of residential areas as far inland as 6 miles.
Category Five: (updated) winds greater than 157 miles per hour (137 kt or higher, 252 km/h or higher). Some complete roof failure on many residences and industrial buildings. All shrubs, trees, and signs blown away. Severe and extensive window and door damage. Low lying escape routes are cut by rising water 3 to 5 hours before arrival of the hurricane eye. Massive evacuation of residential areas on low grounds within 5 to 10 miles of the shoreline may be required.
Additional information on the Saffir-Simpson Hurricane Wind Scale change can be found at: http://www.nhc.noaa.gov/aboutsshws.php |
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