# Hurricanes

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A hurricane is a type of tropical cyclone, the generic term for a low
pressure system that generally forms in the tropics. The ingredients for
a hurricane include a pre-existing weather disturbance, warm tropical
oceans, moisture, and relatively light winds aloft. A typical cyclone is
accompanied by thunderstorms, and in the Northern Hemisphere, a
counterclockwise circulation of winds near the earth's surface. Tropical
cyclones are classified as follows:

-   Tropical Depression. 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.

-   Tropical Storm. 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.

All Atlantic and Gulf of Mexico coastal areas are subject to hurricanes
or tropical storms. Although rarely struck by hurricanes, 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 October.

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
surge along the coast, and cause extensive damage due to inland flooding
from trapped water.

Tornadoes most often occur in thunderstorms embedded in rain bands well
away from the center of the hurricane; however, they also occur near the
eye-wall. Typically, tornadoes produced by tropical cyclones are
relatively weak and short-lived but still pose a threat.

A storm surge is a huge dome of water pushed on-shore by hurricane and
tropical storm winds. Storm surges can reach 25 feet high and be 50-100
miles wide. Storm tide is a combination of the 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). These
phenomena cause severe erosion and extensive damage to coastal areas.

Despite improved warnings and a decrease in the loss of life, property
damage continues to rise because an increasing number of people are
living or vacationing near coastlines. Those in hurricane-prone areas
need to be prepared for hurricanes and tropical storms.

Hurricanes are classified into five categories based on their wind
speed, central pressure and damage potential (see chart below). Category
Three and higher are considered major hurricanes, though Category One
and Two are still extremely dangerous and warrant your full attention.

### Inland/freshwater flooding from hurricanes 

Hurricanes can produce widespread torrential rains. Floods are the
deadly and destructive result. Excessive rain can also trigger
landslides or mud slides, especially in mountainous regions. Flash
flooding can occur due to the intense rainfall. Flooding on rivers and
streams may persist for several days or more after the storm.

The speed of the storm and the geography beneath the storm are the
primary factors regarding the amount of rain produced. Slow moving
storms and tropical storms moving into mountainous regions tend to
produce more rain.

Between 1970 and 1999, more people lost their lives from freshwater
flooding associated with landfalling tropical cyclones than from any
other weather hazard related to tropical cyclones.

See the "Floods" chapter for more specific information on flood related
emergencies.

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### What to do before a hurricane

1.  Know the difference between "Watches" and "Warnings."

    -   Hurricane/Tropical Storm Watch---Hurricane/tropical storm
        conditions are possible in the specified area, usually within 36
        hours.

    -   Hurricane/Tropical Storm Warning---Hurricane/tropical storm
        conditions are expected in the specified area, usually within 24
        hours.

    -   Short Term Watches and Warnings---These warnings provide
        detailed information on specific hurricane threats, such as
        flash floods and tornadoes. Listen for local radio or television
        weather forecasts. Purchase a NOAA Weather Radio with battery
        backup and a tone-alert feature that automatically alerts you
        when a Watch or Warning is issued (tone alert is not available
        in some areas). Purchase a battery-powered commercial radio and
        extra batteries as well because information on other events will
        be broadcast by the media.

2.  Ask your local emergency management office about community
    evacuation plans relating to your neighborhood. Learn evacuation
    routes. Determine where you would go and how you would get there if
    you needed to evacuate. Sometimes alternate routes are desirable.

3.  Talk to your household about hurricane issues. Create a household
    disaster plan. Plan to meet at a place away from your residence in
    case you are separated. Choose an out-of-town contact for everyone
    to call to say they are safe.

4.  Determine the needs of your household members who may live elsewhere
    but need your help in a hurricane. Consider the special needs of
    neighbors, such as people that are disabled or those with limited
    sight or vision problems.

5.  Prepare to survive on your own for at least three days. Assemble a
    disaster supply kit. Keep a stock of food and extra drinking water.
    See the "Emergency Planning and Disaster Supplies" and "Evacuation"
    chapters for more information.

6.  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 breaking.

7.  Learn how to shut off utilities and where gas and water shutoffs are
    located. Do not actually shut off the gas to see how it works or to
    show others. Only the gas company can safely turn it back on.

8.  Have your home inspected for compliance with local building codes.
    Many of the roofs destroyed by hurricanes were not constructed or
    retrofitted according to building codes. Installing straps or
    additional clips to securely fasten your roof to the frame structure
    will substantially reduce roof damage.

9.  Be sure trees and shrubs around your home are well trimmed. Dead
    limbs or trees could cause personal injury or property damage. Clear
    loose and clogged rain gutters and downspouts.

10. If you have a boat, determine where to secure it in an emergency.

11. Consider flood insurance. Purchase insurance well in advance---there
    is a 30-day waiting period before flood insurance takes effect.

12. Make a record of your personal property. Take photographs or
    videotapes of the exterior and interior of your home, including
    personal belongings. Store these documents in a safe place, such as
    a safe deposit box.

### What to do during a hurricane threat

1.  Listen to radio or television newscasts. If a hurricane "Watch" is
    issued, you typically have 24 to 36 hours before the hurricane hits
    land.

2.  Talk with household members. Make sure everyone knows where to meet
    and who to call, in case you are separated. Consider the needs of
    relatives and neighbors with special needs.

3.  Secure your home. Close storm shutters. Secure outdoor objects or
    bring them indoors. Moor your boat if time permits.

4.  Gather several days' supply of water and food for each household
    member. Water systems may become contaminated or damaged. After
    sterilizing the bathtub and other containers with a diluted bleach
    solution of one part bleach to ten parts water, fill them with water
    to ensure a safe supply in case you are unable or told not to
    evacuate. Refer to the "Shelter and Emergency Planning" and
    "Disaster Supplies" chapters for important information.

5.  If you are evacuating, take your disaster supply kit with you to the
    shelter. Remember that alcoholic beverages and weapons are
    prohibited within shelters. Also, pets are not allowed in a public
    shelter due to health reasons. See the "Animals in Disaster" chapter
    and contact your local humane society for additional information.

6.  Prepare to evacuate. Fuel your car---service stations may be closed
    after the storm. If you do not have a car, make arrangements for
    transportation with a friend or relative. Review evacuation routes.
    If instructed, turn off utilities at the main valves.

7.  Evacuate to an inland location, if:

    -   Local authorities announce an evacuation and you live in an
        evacuation zone.

    -   You live in a mobile home or temporary structure---they are
        particularly hazardous during hurricanes no matter how well
        fastened to the ground.

    -   You live in a high-rise. Hurricane winds are stronger at higher
        elevations.

    -   You live on the coast, on a floodplain near a river or inland
        waterway.

    -   You feel you are in danger.

    -   When authorities order an evacuation:

    -   Leave immediately.

    -   Follow evacuation routes announced by local officials.

    -   Stay away from coastal areas, riverbanks and streams.

    -   Tell others where you are going.

8.  If you are not required or are unable to evacuate, stay indoors
    during the hurricane and away from windows and glass 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.

    -   If not instructed to turn off, turn the refrigerator to its
        coldest setting and keep closed.

    -   Turn off propane tanks.

9.  In strong winds, follow these rules:

    -   Take refuge in a small interior room, closet or hallway.

    -   Close all interior doors. Secure and brace external doors.

    -   In a two-story residence, go to an interior first-floor room,
        such as a bathroom or closet.

    -   In a multiple-story building, go to the first or second floors
        and stay in interior rooms away from windows.

    -   Lie on the floor under a table or another sturdy object.

10. Avoid using the phone except for serious emergencies. Local
    authorities need first priority on telephone lines.

11. See the "Evacuation" chapter for important information.

### What to do after a hurricane

1.  Stay where you are if you are in a safe location until local
    authorities say it is safe to leave. If you evacuated the community,
    do not return to the area until authorities say it is safe to
    return.

2.  Keep tuned to local radio or television stations for information
    about caring for your household, where to find medical help, how to
    apply for financial assistance, etc.

3.  Drive only when necessary. Streets will be filled with debris. Roads
    will have weakened and could collapse. Do not drive on flooded or
    barricaded roads or bridges. Roads are closed for your protection.
    As little as six inches of water may cause you to lose control of
    your vehicle---two feet of water will carry most cars away.

4.  Do not drink or prepare food with tap water until notified by
    officials that it is safe to do so.

5.   5. Consider your family's health and safety needs. Be aware of
    symptoms of stress and fatigue. Keep your household together and
    seek crisis counseling if you have need. See the "Mental Health and
    Crisis Counseling" section of the "Recovering from Disaster" chapter
    for more information.

6.  Talk with your children about what has happened and how they can
    help during the recovery. Being involved will help them deal with
    the situation. Consider the needs of your neighbors. People often
    become isolated during hurricanes.

7.  Stay away from disaster areas unless local authorities request
    volunteers. If you are needed, bring your own drinking water, food
    and sleeping gear.

8.   8. Stay away from riverbanks and streams until potential flooding
    has passed. Do not allow children to play in flooded areas. There is
    a high risk of injury or drowning in areas that may appear safe.

9.   9. Stay away from moving water. Moving water only six inches deep
    can sweep you off your feet. Standing water may be electrically
    charged from underground or downed power lines.

10. Stay away from downed power lines and report them to the power
    company. Report broken gas, sewer or water mains to local officials.

11. Don\'t use candles or other open flames indoors. Use a flashlight to
    inspect damage.

12. Set up a manageable schedule to repair property.

13. Contact your insurance agent. An adjuster will be assigned to visit
    your home. To prepare:

    -   Take photos of your belongings and your home or videotape them.

    -   Separate damaged and undamaged belongings.

    -   Locate your financial records.

    -   Keep detailed records of cleanup costs.

14. Consider building a "Safe Room or Shelter" to protect your
    household. See the "Thunderstorms" chapter for additional
    information in the "Tornadoes" section.

15. See the "Recovering From Disaster" chapter for more important
    information.

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