SAFFIR/SIMPSON HURRICANE SCALE
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 forces-National Oceanic and Atmospheric
Administration's hurricane forecasters use a disaster-potential
scale which assigns storms to five categories. Category 1 is a
minimum hurricane; category 5 is the worst case. The criteria
for each category are shown below.
This can be used to give an estimate of the potential property
damage and flooding expected along the coast with a hurricane.
CATEGORY Definition - Effects
ONE Winds 74-95 mph: No real damage to building
structures. Damage primarily to unanchored mobile
homes, shrubbery, and trees. Also, some coastal
road flooding and minor pier damage.
TWO Winds 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 Winds 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 Winds 131-155 mph: More extensive curtainwall
failures with some complete roof structure failure
on small residences. Major erosion of beach areas.
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 Winds 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.
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