All Hurricanes are dangerous, but some are more so than others. The way storm
surge, wind and other factors combine determines the hurricanes destructive
power. To make comparisons easier and to make the predicted hazards of
approaching hurricanes clearer to emergency managers, National Oceanic and
Atmospheric Administration's hurricane forecasters use a disaster-potential
scale which assigns storms to five categories. This can be used to give an
estimate of the potential property damage and flooding expected along the coast
with a hurricane.
The scale was formulated in 1969 by Herbert Saffir, a consulting engineer,
and Dr. Bob Simpson, director of the National Hurricane Center. The World
Meteorological Organization was preparing a report on structural damage to
dwellings due to windstorms, and Dr. Simpson added information about storm surge
heights that accompany hurricanes in each category.
Category
Winds
Effects
One
74-95 mph
No real damage to building structures. Damage primarly to unanchored mobile
homes, shrubbery, and trees. Also, some coastal road flooding and minor pier
damage
Two
96-110 mph
Some roofing material, door, and window damage to buildings. Considerable
damage to vegetation, mobile homes, and piers. Coastal and low-lying escape
routes flood 2-4 hours before arrival of center. Small craft in unprotected
anchorages break moorings.
Three
111-130 mph
Some structural damage to small residences and utility buildings with a
minor amount of curtainwall failures. Mobile homes are destroyed. Flooding near
the coast destroys smaller structures with larger structures damaged by floating
debris. Terrain continuously lower than 5 feet ASL may be flooded inland 8 miles
or more.
Four
131-155 mph
More extensive curtainwall failures with some complete roof strucutre
failure on small residences. Major erosion of beach. Major damage to lower
floors of structures near the shore. Terrain continuously lower than 10 feet ASL
may be flooded requiring massive evacuation of residential areas inland as far
as 6 miles.
Five
greater than 155 mph
Complete roof failure on many residences and industrial buildings. Some
complete building failures with small utility buildings blown over or away.
Major damage to lower floors of all structures located less than 15 feet ASL and
within 500 yards of the shoreline. Massive evacuation of residential areas on
low ground within 5 to 10 miles of the shoreline may be required.
Examples
Category
Sustained Winds (MPH)
Description
Examples
1
74-95
Minimal
Florence (1988) LA | Charley (1988) NC
2
96-110
Moderate
Kate 1985 FL | Bob 1991 NY
3
111-130
Extensive
Alicia 1983 TX
4
131-155
Extreme
Andrew 1992 FL | Hugo 1989 NC
5
>155
Catastrophic
Camille 1969 MS | Labor Day Hurricane 1935 FL
Keys