TROPICAL DEPRESSION
Designated
when a clearly defined area of
Low
pressure has developed. Usually it occurs
Within
an area of enhanced thunderstorm activity.
The highest
wind speed is 38 mph.
TROPICAL
STORM
The
wind speed has increased to 39-73 mph, as the now
Distinct
low-pressure area is well defined by a rotating
Circulation.
The storm is now given a name.
HURRICANE
Once a
tropical storm's constant wind speed reaches
74 mph
or greater, it is classified as a hurricane.
TROPICAL
STORM WATCH
An
announcement for specific areas that a tropical storm,
Or the
potential of a newly developing storm, poses a threat
To
coastal areas, generally within 36 hours.
TROPICAL
STORM WARNING
A
warning that tropical storm conditions, including possible
Sustained
winds within the range of 39-73 mph, are expected
In
specific coastal areas within 24 hours.
HURRICANE
WATCH
An
announcement for specific areas that a hurricane or
Hurricane
conditions pose a threat to a coastal area,
Generally
within 36 hours.
HURRICANE
WARNING
A
warning that a hurricane is expected in a specified
Coastal
area within 24 hours. When a hurricane warning is
Issued,
all precautions should be taken immediately. If the
Hurricane
path is unusual or erratic, the warning may be
Issued
only a few hours before the beginning of hurricane
Conditions.
SMALL
CRAFT ADVISORY
When
winds 29-38 mph (25-33 knots) or hazardous wave
Conditions
threaten a coastal area, small craft operators are
Advised
to remain in port or not venture into the open sea.
STORM
SURGE
The
combination of storm surge, battering waves and high
Tide is
often the hurricane's most dangerous aspect.
The
storm surge is a large dome of water, 50-100 miles wide,
That
sweeps across the coastline near and to the right of where
The
hurricane makes landfall. The surge, aided by the
Hammering
effect of breaking waves, sweeps everything in
Its
path. Often, this is the most dangerous part of the
Hurricane.
Nine out of ten hurricane fatalities are caused
By the
storm surge.
ONE
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
Some
roofing material, door, and window
Damage
of 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
Some
structural damage to small residences and utility buildings with a minor
Amount
of curtain wall failures. Mobile homes are destroyed. Flooding near
The
coast destroys smaller structures, with larger structures damaged by
Floating
debris. Terrain continuously lowers than 5 feet above mean sea level
(ASL)
may be flooded inland as far as 8 miles.
FOUR
More
extensive curtain wall failures with some complete roof
Structure
failure on small residences. 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
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 of ASL and within
500
yards of the shoreline. Massive evacuation of residential
Areas
on low ground within 5-10 miles of the shoreline may be
Required.
