A hurricane is a type
of tropical cyclone, the generic term for
a low pressure system that generally forms
in the tropics. A typical cyclone is accompanied
by thunderstorms, and in the Northern Hemisphere,
a counterclockwise circulation of winds
near the earth’s surface.
All Atlantic and Gulf of Mexico coastal
areas are subject to hurricanes or tropical
storms. Parts of the Southwest United States
and the Pacific Coast experience heavy
rains and floods each year from hurricanes
spawned off Mexico. The Atlantic hurricane
season lasts from June to November, with
the peak season from mid-August to late
Hurricanes can cause catastrophic damage
to coastlines and several hundred miles
inland. Winds can exceed 155 miles per
hour. Hurricanes and tropical storms can
also spawn tornadoes and microbursts, create
storm surges along the coast, and cause
extensive damage from heavy rainfall.
Hurricanes are classified into five categories
based on their wind speed, central pressure,
and damage potential (see chart). Category
Three and higher hurricanes are considered
major hurricanes, though Categories One
and Two are still extremely dangerous and
warrant your full attention.
Hurricanes can produce widespread torrential
rains. Floods are the deadly and destructive
result. Slow moving storms and tropical
storms moving into mountainous regions
tend to produce especially heavy rain.
Excessive rain can trigger landslides or
mud slides, especially in mountainous regions.
Flash flooding can occur due to intense
rainfall. Flooding on rivers and streams
may persist for several days or more after
(Category, Sustained Winds, Damage, Storm
- 74-95 Minimal: Unanchored
mobile homes, vegetation, and signs 4-5
- 96-110 Moderate:
All mobile homes, roofs, small craft;
flooding 6-8 feet
- 111-130 Extensive:
Small buildings; low-lying roads cut
off 9-12 feet
- 131-155 Extreme:
Roofs destroyed, trees down, roads cut
off, mobile homes destroyed, beach homes
flooded 13-18 feet
- More than 155
buildings destroyed, vegetation destroyed,
major roads cut off, homes flooded
Between 1970 and 1999, more people
lost their lives from freshwater inland
flooding associated with land falling
tropical cyclones than from any other
weather hazard related to tropical
Naming the Hurricane
Since 1953, Atlantic tropical storms have
been named from lists originated by the
National Hurricane Center and now maintained
and updated by an international committee
of the World Meteorological Organization.
The lists featured only women’s names
until 1979. After that, men’s and
women’s names were alternated. Six
lists are used in rotation. Thus, the 2001
lists will be used again in 2007.
The only time there is
a change in the list is if a storm is so
deadly or costly that the continued use
of the name would be inappropriate for
reasons of sensitivity. When this occurs,
the name is stricken from the list and
another name is selected to replace it.
Sometimes names are changed.
Lorenzo replaced Luis and Michelle replaced
Marilyn. The complete lists can be found
at www.nhc.noaa.gov under “Storm
Familiarize yourself with these terms to
help identify a hurricane hazard:
An organized system of clouds and thunderstorms
with a defined surface
circulation and maximum sustained winds
of 38 MPH (33 knots) or less.
Sustained winds are defined as one-minute
average wind measured at
about 33 ft (10 meters) above the surface.
An organized system of strong thunderstorms
with a defined surface circulation
and maximum sustained winds of 39-73
MPH (34-63 knots).
- Hurricane -
An intense tropical weather system
of strong thunderstorms with a well-defined
surface circulation and maximum sustained
winds of 74 MPH
(64 knots) or higher.
A dome of water pushed onshore by hurricane
and tropical storm winds.
Storm surges can reach 25 feet high
and be 50-100 miles wide.
A combination of storm surge and the
normal tide (i.e., a 15-foot storm
surge combined with a 2-foot normal
high tide over the mean sea level
creates a 17-foot storm tide).
Storm Watch -
Hurricane/tropical storm conditions
are possible in the specified area,
usually within 36 hours. Tune in to
NOAA Weather Radio, commercial
radio, or television for information.
Storm Warning -
Hurricane/tropical storm conditions
are expected in the specified area,
usually within 24 hours.
Term Watches and Warnings -
These warnings provide detailed information
about specific hurricane
threats, such as fl ash floods and
Before a Hurricane
To prepare for a hurricane,
you should take the following measures:
- Make plans to secure your property.
Permanent storm shutters offer the
best protection for windows. A second
option is to board up windows with 5/8” marine
plywood, cut to fit and ready to install.
Tape does not prevent windows from
- Install straps or additional clips
to securely fasten your roof to the
This will reduce roof damage.
- Be sure trees and shrubs around
your home are well trimmed.
- Clear loose and clogged rain gutters
- Determine how and where to secure
- Consider building a safe room.
If a hurricane
is likely in your area, you should:
- Listen to the radio
or TV for information.
- Secure your home, close storm shutters,
and secure outdoor objects or bring
- Turn off utilities if instructed
to do so. Otherwise, turn the refrigerator
thermostat to its coldest setting
and keep its doors closed.
- Turn off propane tanks.
- Avoid using the phone, except for
- Moor your boat if time permits.
- Ensure a supply of water for sanitary
purposes such as cleaning and flushing
toilets. Fill the bathtub and other
large containers with water.
You should evacuate under
the following conditions:
- If you are directed by local
authorities to do so. Be sure to follow
- If you live in a mobile home or
shelters are particularly hazardous
during hurricanes no matter how
well fastened to the ground.
- If you live in a high-rise building—hurricane
winds are stronger at higher
- If you live on the coast, on a floodplain,
near a river, or on an inland
- If you feel you are in danger.
you are unable to evacuate, go to your
wind-safe room. If you do not have one,
follow these guidelines:
- Stay indoors during the hurricane
and away from windows and glass
- Close all interior doors—secure
and brace external doors.
- Keep curtains and blinds closed.
Do not be fooled if there is a lull;
it could be the eye of the storm—winds
will pick up again.
- Take refuge in a small interior
room, closet, or hallway on
the lowest level.
- Lie on the floor under a table or
another sturdy object.
If you require more information
about any of these topics, the
resources that may be helpful.
Against the Wind:
Protecting Your Home from Hurricane and
Wind Damage. FEMA-247. A guide
to hurricane preparedness. Available
online at FEMA - Against the Wind: Protecting your Home from Hurricane and Wind Damage
Hurricane Preparedness. IS-324. CD-ROM
or Web-based training course for
federal, state, and local emergency
managers. Web-based version available
Tips for Hurricanes. L 105. Publication
for teachers and parents for presentation
to children. To order, call 1(800)480-2520.
Your Home against Hurricane Damage, Institute for
Business and Home Safety. 110 William
Street, New York, NY 20038