The Saffir/Simpson Hurricane Scale
The Saffir/Simpson Hurricane Scale is used by the National Weather Service to
give public safety and government officials an assessment of the potential wind
and storm surge damage from a hurricane.
The scale ranges from Category 1, the least intense, to Category 5, the
strongest. The scale was developed by Herbert Saffir, a Dade County Florida
Consulting Engineer, and Dr. Robert H. Simpson, a former Director of the
National Hurricane Center.
The scale assessment categories are as follows:
Category 1 - Winds of 74 - 95 mph and storm surge generally 4
- 5 feet above normal. Damage limited to unanchored mobile homes, shrubbery, and
trees. Some damage to poorly constructed signs. Limited coastal road flooding
and minor pier damage may occur. Hurricanes Erin in 1995 and Danny in 1997 were
category 1 hurricanes.
Category 2 - Winds of 96 - 110 mph and storm surge generally 6
- 8 feet above normal. Some roofing material, door, and window damage to
buildings. Considerable damage to shrubbery and trees. Some trees blown down.
Considerable damage to mobile homes, poorly constructed signs, and piers.
Coastal and low-lying escape may flood as the storm approaches land. Small
craft in unprotected anchorages break moorings. Hurricane Bertha in 1996 was a
category 2 hurricane when it hit the North Carolina coast.
Category 3 -Winds of 111 - 130 mph and storm surge generally 9
- 12 feet above normal. Some structural damage to homes and utility buildings
with unprotected openings and a minor amount of curtainwall failures. Foliage
blown off trees. Large trees blown down. Mobile homes and poorly constructed
signs are destroyed. Coastal and low-lying escape routes will flood as the
storm approaches the coast. Storm surge and waves will destroy coastal small
structures with larger structures damaged by floating debris. Hurricane Opal in
1995 was a category 3 hurricane when it made landfall near Pensacola Beach.
Category 4 - Winds 131 - 155 mph and storm surge generally 13
- 18 feet above normal. More extensive curtainwall failures with some complete
roof structure failure on buildings without proper anchoring and strapping.
Shrubs, trees, and all signs are blown down. Complete destruction of mobile
homes. Extensive damage to unprotected doors and windows. Coastal and low-lying
escape routes will flood as the storm approaches the coast. Storm surge will
cause major damage to structures near the coast and floating debris will cause
damage to inland buildings near the coast. Hurricane Hugo in 1989 and Hurricane
Andrew in 1992 were category 4 hurricanes.
Category 5 - Winds in excess of 155 mph and storm surge
generally greater that 18 feet. Complete roof failure on many residences and
commercial buildings without proper strapping and anchoring. Some complete
building failures with small utility buildings blown away. All shrubs, trees,
and signs blown down. Complete destruction of mobile homes. Severe and
extensive damage to unprotected doors and windows. Coastal and low-lying areas
will flood as the storm approaches the coast. Destruction of structures along
the coast from storm surge and waves. Extensive damage to inland homes near the
coast from floating debris. Hurricane Gilbert in 1988 and Hurricane Camille in
1969 were category 5 storms.
|
CATEGORY |
WINDSPEED |
MILIBARS OF MERCURY |
INCHES |
STORM SURGE |
1 |
75 - 95 MPH |
1000 - 980 |
+28.94 |
4 - 5 FEET |
2 |
96 - 110 MPH |
979 - 965 |
28.91 - 28.50 |
6 - 8 FEET |
3 |
111 - 130 MPH |
964 - 945 |
28.47 - 27.91 |
9 - 12 FEET |
4 |
131 - 155 MPH |
944 - 920 |
27.88 - 27.17 |
13 - 18 FEET |
5 |
> 155 MPH |
< 920 |
< 27.17 |
> 18 FEET |