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Protect yourself from killer
tornadoes By Lamar James Extension Communications
Specialist 501-671-2187 Tornadoes can be deadly.
With new warning systems, you can be alerted before the tornado is visible. This
additional time makes tornado survival more likely. During bad weather, you must
be alert and tune in for warnings. If a tornado should strike,well-made plans
for emergency shelter can overcome this disaster and bring you, your family and
your community through without personal injury. What You Can Do Before
the Storm: Develop an emergency storm plan for all family members
whether at home, work, school or outdoors. Teach children their county and neighboring counties because
storm alerts are given by counties. Keep highway maps in several convenient
locations to follow storm movements given by weather bulletins. Conduct frequent storm drills. Have a NOAA Weather Radio with a battery back-up and warning
alarm to receive warnings. Listen to TV or radio for weather updates. If your activity is outdoors, listen to the latest forecasts
and take necessary precautions (possibly delaying activities until the danger is
past) during threatening weather. If a Tornado Warning
is Issued or Threatening Weather Approaches: Move to a previously
designated safe area, preferably a basement. If an underground shelter is not available, move to an
interior room or hallway on the lowest floor. Crouching under a sturdy desk or
rugged furniture is advisable if they are located near a central wall. Place
pillows or blankets over your head and upper Stay away from doors and windows. Do not try to outrun a tornado in your car. Instead, leave it
immediately. If caught outside or in a vehicle, get out and lie flat in Do not take shelter under highway overpasses. If a tornado strikes,
watch out for fallen power lines. Stay out of damaged areas until power is
disconnected to avoid accidental electrical shock. Know the Difference
Between a Tornado Watch and a Tornado Warning TORNADO WATCH. . . Tornadoes are possible in your area. Remain
alert for approaching storms. Listen to NOAA Weather Radio, commercial TV or radio for
weather information. TORNADO WARNING. . . A tornado has been sighted or indicated
by weather radar. If you may be in the path of the storm, move to a previously
designated safe area. Tornado watches and warnings are issued as soon as the
conditions are identified. Use the available time, once you note a warning, to
prepare for one of nature’s most destructive storms. Stay informed about the
approaching storm. Sometimes tornadoes develop so rapidly that advance warning is
not possible. Remain alert for signs of an approaching tornado. Doppler Radar Do you know that new Doppler radar units can detect tornadoes
that are forming? Doppler radar measures wind speeds and the direction of air
currents within storms. This capability really enhances identification because a
tornado is simply a violently rotating column of air, pendant from a
cumulonimbus (thunderstorm) cloud. Conventional radar gave only rainfall
intensity and "storm conditions." Doppler radar capabilities improve
the accuracy and timeliness of National Weather Service bulletins. Doppler radar units are located at National Weather Service
offices in Little Rock and Fort Smith, Arkansas; Memphis, Tennessee; Tulsa,
Oklahoma; Jackson, Mississippi; Shreveport, Louisiana; and Springfield,
Missouri. Arkansas Statistics Tornadoes occur in
many parts of the world. However, three-fourths of the world’s tornadoes occur
in the U.S. These violent storms occur most frequently in the United States east
of the Rocky Mountains during the spring and summer months. Arkansas is located in the lower
Mississippi Valley where warm, moist air flowing northward from the Gulf of
Mexico interacts with cool, dry air spreading southward and eastward from the
Great Plains. During the 50 years
from 1950-1999, 1,073 tornadoes have struck Arkansas. Records show that they can
occur any day of the year and any time of day. Tornado preparation requires
constant vigilance. While tornadoes in
Arkansas normally occur during the spring and fall months, they can occur in any
month. A total of 68 tornadoes occurred in January, 1999. This set a national
record for the greatest number of tornadoes in the month of January. During 1999, 107 tornadoes
were sighted, setting a new record for Arkansas. Tornadoes occur with
greater frequency during late afternoon to late evening, according to the
National Weather Service records. In Arkansas, five in the afternoon is the time
of the maximum tornado incidence. The greater tornado
frequency during afternoons and evenings can largely be explained from patterns
of increased instability in the atmosphere. This air instability results from a
buildup of heat near the earth’s surface on warm afternoons. After sunset the layer of heated air near the
earth’s surface begins to cool. This usually restores more atmospheric
stability and reduces the threat of tornadoes. Any period of
unseasonably warm and humid conditions should trigger caution about the
possibility of a tornado. Monitor weather bulletins and watch the sky during
approaching thunderstorms. Violently moving clouds indicate high air velocities
which may develop into a tornado. Tornadoes have killed
a total of 1,503 Arkansans since 1880. A "killer" tornado is a tornado
that causes the death of at least one person. The worst killer storms in the
state’s history occurred March 21, 1952. That day three tornadoes killed 111 persons and injured an
additional 772. In recent years, an average of five Arkansans have died from
tornadoes each year. Tornado Variability Recognizing conditions
that may develop into tornadic winds is the first major step in avoiding this
cruel disaster. Weather broadcasts can help avert tragedy. Be prepared to find
suitable protection. Flying debris from tornadoes cause most deaths and injuries. Most tornado
damage is probably caused by winds of 125 mph; however, maximum wind velocities
may exceed 250 mph. The most damaging storm occurred in the Fort Smith-Van Buren
areas on April 21, 1996, with associated costs around $300 million. Surface winds in
connection with developing tornadoes are usually from the southwest. Sixty-four
percent of the tornadoes in Arkansas move from the southwest to the northeast.
But tornadoes can come from any direction. Some tornadoes have stopped their forward
movement, turned, and looped back across their path. Their average speed of
advance is 30 mph, but a few move as fast as 70 mph. The diversity of their
approach patterns and speed demands alertness, especially after a tornado
warning has been issued for your area. Refrain from driving to locate family or
friends. Make phone calls to notify those who may have missed the tornado warning broadcast, but keep
an alert eye on the sky. Tornado Identification Violent storms
associated with low barometric pressures can spawn a tornado. Strong winds in
the lower few thousand feet of the atmosphere may be noted by cloud movements.
The storm cells develop from 20,000 to 40,000 feet elevation. Rotation of air (cloud movement) usually
starts with a circulation near 20,000 feet and builds up and down. Tornadoes often form
near a thunderstorm’s updraft. Often surface winds of 25-35 miles per hour are
noted near a developing tornado. Small clouds will rise quickly into the larger
cloud layer. Near a tornado the barometric pressure drops rapidly. The characteristic funnel may
drop down, loop and appear to dissipate at times. If a funnel is
sighted, take shelter immediately. Tornadoes can reach you within a few minutes.
Other funnels can spawn directly overhead. Tornadoes may
"mature" in a classic fashion. However, be aware that violent storm
cells can cause two or more circulations. It is important to have a good view of
the entire sky to avoid being surprised by another funnel that was obscured
behind a ridge, buildings or a row of trees. Any time you are
observing a storm, be alert to the potential of being struck by lightning.
Standing near a tree or house that projects above the landscape during violent
weather risks being in a deadly path of lightning discharge. Any vertical
projections, especially metal structures,
can readily attract a fatal electrical current. Tornadoes occur all
over Arkansas. It is important to have a tornado plan and review it annually. If
changes in a community warning system have occurred or a better shelter is now
available nearby, take advantage of the new opportunities. Steps to survive a tornado are
simpler and more important than earthquake precautions. Disaster Plans Everyone should have a
disaster plan to survive a tornado. Follow these basic steps to develop a family
tornado disaster plan: 1. Find out if your
community has tornado warning sirens. Learn your community’s warning signals
and evacuation plans. Locate the safest areas in your home. To be better
prepared for a tornado, contact your local National Weather Service office, local Office of Emergency
Management, American Red Cross Chapter or county Cooperative Extension office to
determine what they can provide. 2. Meet with your
family to create a plan. Discuss the tornado warning measures available to you.
Point out the safest areas in your home to assure that everyone knows where to
go for shelter. 3. Practice emergency drills
and maintain your plan. Ask questions to make sure each family member remembers
the meeting place. Assemble in the assigned tornado shelter. Remind each one to
use the telephone only if there is no immediate danger and then only to notify
other family members of the violent weather concern or tornado watch. Post
emergency phone numbers and safety rules by the telephone. Teach children how
and when to call 911 or the local emergency medical service number. 4. Improve your plan.
(a) Review the emergency phone numbers posted by the telephones. (b) Install
fire extinguishers and make other safety improvements to your house. (c) Teach
your family how to use a fire extinguisher and how and when to turn off water, gas and
electricity. (d) Review basic safety measures and/or enroll in CPR and first aid
classes. (e) Maintain supplies in your home to meet your emergency needs for at
least three days. Assemble a disaster supply kit with items needed for an
evacuation. Store these supplies in sturdy, easy-to-carry containers such as
backpacks or duffel bags. 5. Protect valuable
records. Maintain a safety-deposit box for family and business papers that
cannot be replaced. Review specific wind and flood damage protection provided by
your insurance policy. Prepare records that will help verify losses for
insurance, tax or federal disaster declarations. 6. Test and recharge
(as needed) your fire extinguishers according to the manufacturer’s
instructions. Replace stored water every six months. School Disaster Plans (Hospitals, nursing
homes and other institutions should develop similar plans.) Develop a severe weather action plan and have frequent
drills. Assign responsibility for activating the severe weather
plan. This includes assuring severe weather is continually monitored with NOAA
Weather Radio and local TV/radio. Make sure several leaders know how to turn off
electricity and gas in the event the school is damaged. Each school structure should be inspected and tornado
shelter areas designated by a registered engineer or architect. Schools without
basements should use interior rooms and hallways on the lowest floor and away
from windows. If the primary power for the school’s alarm is electricity,
provide a charged-battery backup or have a compressed air horn or megaphone to
activate the alarm during power outages. Have provisions for disabled students and those in
portable classrooms. Move students quickly into interior rooms or hallways on the
lowest floor. Have them assume the tornado protection position. Lunches, classes, or assemblies in large, free-span
cafeterias or auditoriums should be delayed if severe weather is anticipated. Do not remain in auditoriums, cafeterias, gymnasiums or other
structures with wide, free-span roofs because they offer no protection from
tornado-strength winds. Keep children at school beyond regular hours if
threatening weather is expected. Children are safer at school than in a bus or
car. Students should not be sent home early if severe weather is approaching. NOAA Weather Radio Weather information
can be received 24 hours a day from NOAA Weather Radio. In Arkansas, this is a
joint effort between the National Weather Service and the state. The latest
weather information is broadcast all day and all night, including severe Special radio
receivers are available at radio shops, electronics stores, department stores
and discount stores. Many multiband radios and scanners can also receive the Some radio receivers
have a "warning alarm" feature for severe weather watches or warnings
that allows the National Weather Service to automatically turn on the radio, day
or night. This warning alarm is tested each Wednesday between 11 a.m. and noon.
If bad weather is occurring or is forecast, the test is postponed until the next
good-weather day. Transmitter Locations
and Assigned Frequencies (mhz) Mountain View
162.40 Little Rock
162.55 Jonesboro
162.55 Memphis
162.475 Tornado Safety Locations Homes With Basements Seek refuge near the basement wall in the most sheltered and
deepest part of the basement below ground. Homes Without Basements Take cover in the smallest room with stout walls, or
under heavy furniture, or a tipped-over, sturdy upholstered couch or chair near
the center of the house. The first floor is safer than the second or third. Don’t take time to open or close windows; get away
from them and go to a safe area immediately.
Construction of a storm cellar is particularly advisable for those in
homes without basements. Mobile Homes and Modular Buildings Abandon mobile homes. Arrange for use of a convenient safe
area in advance, should violent weather occur. Consider basements, a storm cellar, the ground floor of
a sturdy structure or a nearby culvert or deep ditch. Factories, Auditoriums and Other Large Buildings With
Wide, Free-Span Roofs These buildings are particularly vulnerable to tornadic
wind damage due to the large roof expanse upon which wind forces act and the
distance between roof-supporting walls. Basements of these buildings offer
reasonably good protection. Smaller interior rooms at ground level or nearby
sturdy buildings are options, depending
on their construction and the urgency for shelter. Pre-select and mark
designated safe areas. Hold tornado safety drills. Train building employees to
direct occupants to designated safe areas. Trained spotters should assume their
posts as soon as conditions become threatening. Office Buildings The basement or an interior hallway on a lower floor of
an office building is safest. Upper stories are unsafe.
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