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Destruction Caused by Hurricanes
saffir-simpson scale and dangerous features
Once a hurricane develops, the Saffir-Simpson Scale is used to
classify a hurricane's damage potential. There are five possible categories,
from 1-5.
Saffir-Simpson Hurricane Damage-Potential Scale
Scale Number Category |
Central Pressure mb inches |
Wind Speeds mi/hr knots |
Storm Surge feet meters |
Observed Damage |
1 |
>=980
>=28.94 |
74-95
64-82 |
4-5
~1.5 |
some damage to trees, shrubbery, and unanchored mobile homes
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2 |
965-979
28.50-28.91 |
96-110
83-95 |
6-8
~2.0-2.5 |
major damage to mobile homes; damage buildings' roofs, and blow trees down
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3 |
945-964
27.91-28.47 |
111-130
96-113 |
9-12
~2.5-4.0 |
destroy mobile homes; blow down large trees; damage small buildings
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4 |
920-944
27.17-27.88 |
131-155
114-135 |
13-18
~4.0-5.5 |
completely destroy mobile homes; lower
floors of structures near shore are susceptible to flooding
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5 |
<"920"
<"27.17" |
>"155"
>"135" |
>"18"
>"5.5" |
extensive damage to homes and industrial buildings;
blow away small buildings; lower floors of structures within 500
meters of shore and
less than 4.5 m (15 ft) above sea level
are damaged
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Table from:
Ahrens (1994)
In addition to the high winds associated with
hurricanes, other components associated with
these storms can inflict significant amounts of damage.
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Flooding:
Heavy rains and ocean waters brought ashore by strong winds
can cause flooding
in excess of
50 cm (20 in) over a 24 hour period.
The runoff systems in many cities are unable to handle such an increase in water
because of the gentle topography common to many of the coastal areas where
hurricanes occur.
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Storm Surge:
An abnormal increase in the ocean's level, sometimes in excess of several
meters high. Probably a hurricane's most devastating feature, storm
surges ravage low-elevation coastal areas.
It is especially damaging when the storm surge occurs during high tide
and consequently, is often responsible for most hurricane-related deaths.
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Tornadoes:
A number of theories exist about their origin,
but in the case of Hurricane Andrew,
severe damage was inflicted by
small spin-up vortices that developed in regions of strong
wind-shear found in the hurricane's
eye wall.
The strong winds of the hurricane frequently hide the smaller tornado
paths, making it difficult to attribute damage caused by one or the other.
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development stages
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Hydrologic Cycle
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