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Hurricane
Watch
The onset of
hurricane conditions is possible within 36 hours
Hurricane Warning
The onset of hurricane conditions is likely within 24
hours.
The Saffir-Simpson Hurricane Scale
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):
- 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.
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- Category Two Hurricane (Winds 96-110 mph):
- 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.
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.
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- Category Three Hurricane (Winds 111-130
mph):
- 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. 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.
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- Category Four Hurricane (Winds 131-155
mph):
- Storm surge generally 13-18 ft above normal. More
extensive curtain wall 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).
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.
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- Category Five Hurricane (Winds greater
than 155 mph ):
- 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.
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 one
of the strongest Atlantic tropical cyclones of record.
Source: NOAA
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