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Glenroy
Brown,
Categories of Hurricane
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 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. Hurricanes
Allison of 1995 and Danny of 1997 were Category One hurricanes at peak intensity.
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 centre. Small craft in unprotected anchorages break moorings. Hurricane Bonnie of
1998 was a Category Two hurricane when it hit the North Carolina coast, while Hurricane Georges of
1998 was a Category Two Hurricane when it hit the Florida Keys and the Mississippi Gulf Coast.
Category Three Hurricane:
Winds 111-129 mph (96-112 kt or 178-208 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 tress
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 hurricane centre. Flooding near the coast
destroys smaller structures with larger structures damaged by battering of 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. Hurricanes
Roxanne of 1995 and Fran of 1996 were Category Three hurricanes at landfall on the Yucatan
Peninsula of Mexico and in North Carolina, respectively.
Category Four Hurricane:
Winds 130-156 mph (113-136 kt or 209-251 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 hurricane centre. 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). Hurricane Luis of 1995 was a Category Four
hurricane while moving over the Leeward Islands. Hurricanes Felix and Opal of 1995 also reached
Category Four status at peak intensity.
Category Five Hurricane:
Winds greater than 157 mph (137 kt or 252 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 hurricane
centre. 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. Hurricane Mitch of 1998 was a Category Five
hurricane at peak intensity over the western Caribbean. Hurricane Gilbert of 1988 was a Category
Five hurricane at peak intensity and is the strongest Atlantic tropical cyclone of
record.
Jamaica Weather Report is an established
Jamaican web site that targets internet audience both locally and abroad who are seeking weather
related information about the island of Jamaica.
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