The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane's
present intensity. This is used to give an estimate of the potential property damage and flooding expected along the coast
from a hurricane landfall. Wind speed is the determining factor in the scale, as storm surge values are highly dependent on
the slope of the continental shelf and the shape of the coastline, in the landfall region. Note that all winds are using the
U.S. 1-minute average.
Category One Hurricane:
Winds 74-95 mph (64-82 kt or 119-153 km/hr). Storm surge generally 4-5 ft above
normal. No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage
to poorly constructed signs. Also, some coastal road flooding and minor pier damage.
Some examples: Hurricane Lili of 2002, and Hurricane Gaston 2004
Category Two Hurricane:
Winds 96-110 mph (83-95 kt or 154-177 km/hr). Storm surge generally 6-8 feet
above normal. 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. Coastal and low-lying escape
routes flood 2-4 hours before arrival of the hurricane center. Small craft in unprotected anchorages break moorings.
Some examples: Hurricane Frances of 2004, and Hurricane Isabel of 2003
Category Three Hurricane:
Winds 111-130 mph (96-113 kt or 178-209 km/hr). Storm surge generally 9-12 ft
above normal. 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. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane.
Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain
continuously lower than 5 ft above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying residences
with several blocks of the shoreline may be required.
Some examples: Hurricane Jeanne 2004, and Hurricane Ivan 2004
Category Four Hurricane:
Winds 131-155 mph (114-135 kt or 210-249 km/hr). Storm surge generally 13-18
ft above normal. More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs,
trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying
escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors
of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential
areas as far inland as 6 miles (10 km).
Some examples: Hurricane Charley of 2004, and Hurricane Dennis 2005
Category Five Hurricane:
Winds greater than 155 mph (135 kt or 249 km/hr). Storm surge generally greater
than 18 ft above normal. Complete roof failure on many residences and industrial buildings. Some complete building failures
with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Complete destruction of mobile homes.
Severe and extensive window and door damage. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the
center of the hurricane. Major damage to lower floors of all structures located less than 15 ft above sea level and within
500 yards of the shoreline. Massive evacuation of residential areas on low ground within 5-10 miles (8-16 km) of the shoreline
may be required.
Only 3 Category Five Hurricanes have made landfall in the United States
since records began: The Labor Day Hurricane of 1935, Hurricane Camille (1969), and Hurricane Andrew in August, 1992.
