saffir-Simpson Hurricane Scale
The
Saffir-Simpson Hurricane Scale was developed
in the early 1970s by Herbert Saffir,
a consulting engineer in Coral Gables,
Florida, and Dr. Robert Simpson, then
Director of the National Hurricane Center.
The scale is based primarily on wind speeds
and includes estimates of barometric pressure
and storm surge associated with each of
the five categories. This scale
is used to give an estimate of the potential
property damage and flooding expected
along the coast from a hurricane landfall.
|
Category |
Central
Pressure |
Winds |
Surge |
|
>
980 mb (28.94") |
74-95
mph (64-83 kts) |
4-5
ft |
|
965-979
mb (28.50-28.91") |
96-110
mph (65-96 kts) |
6-8
ft |
|
945-964
mb (27.91-28.47") |
111-130
mph (97-113 kts) |
9-12
ft |
|
920-944
mb (27.17-27.88") |
131-155
mph (114-135 kts) |
13-18
ft |
|
<
920 mb (27.17") |
>
155 mph or 135 kts |
>18
ft |
| |
| Category
One Hurricane: |
Winds
74-95 mph (64-82 kts). 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. |
|
Category
Two Hurricane: |
Winds
96-110 mph (83-95 kts). 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. |
|
Category
Three Hurricane: |
Winds
111-130 mph (96-113 kts). Storm
surge generally 9-12 ft above normal.
Some structural damage to small
residences and utility buildings
with a minor amount of curtain wall
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
center. 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. |
|
Category
Four Hurricane: |
Winds
131-155 mph (114-135 kts). 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 hurricane center.
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).
|
|
Category
Five Hurricane: |
Winds
greater than 155 mph (135 kts).
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 center.
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.
. |
|
|
