Severe Weather Awareness - Tornadoes
Nature's most violent storms
No other country in the world has more tornadoes than the United States.
In an average year, 800 tornadoes are reported in the United States,
resulting in 80 deaths and over 1,500 injuries
|Tornadoes are found most frequently in the United States
east of the Rocky Mountains.
Oklahoma has the highest average number of tornadoes
with 47 each year
South Carolina has an average of
10 tornadoes each year
Georgia has an average of 21 each year
Click Map for Larger Image
Tornadoes are defined as violently
rotating columns of air extending from a thunderstorms to the ground.
What's the difference between a tornado and
a funnel cloud?
Funnel clouds are rotating columns of air not in contact with the ground.
However, the violently rotating column of air may reach the ground very
quickly - becoming a tornado! If there is debris being picked up or blown
around by the "funnel cloud" - the rotating column of air has already
reached the ground and it's a tornado!
How are tornadoes and waterspouts different?
Waterspouts are weak tornadoes that form over warm water. Waterspouts
are most common along the Gulf Coast and southeastern U.S.
coastline. Waterspouts occasionally move inland - as soon as the base of
the rotating column of air moves over land the waterspout becomes a
|How strong are tornadoes?
While most tornadoes (69%) have winds of less than 100
miles an hour, they can be much much stronger. Violent tornadoes (winds
greater than 205 miles an hour) account for only 2% of all tornadoes, they cause
70% of all tornado deaths. In 1931, a tornado in Minnesota lifted an 83-ton
railroad train with 117 passengers and carried it more than 80 feet!
Once a tornado in Oklahoma carried a motel sign 30 miles and dropped it in
Arkansas! In 1975 a Mississippi tornado carried a home freezer more than one mile!
Tornado Wind and Damage Scale
||Frequency of Occurrence
||40 to 72 MPH
||Some damage to chimneys, TV antennas, roof shingles, trees, and windows.
||73 to 112 MPH
||Automobiles overturned, carports destroyed, trees uprooted
||113 to 157 MPH
||Roofs blown off homes, sheds and outbuildings demolished, mobile homes overturned.
||158 to 206 MPH
||Exterior walls and roofs blown off homes. Metal buildings collapsed or are severely damaged. Forests and farmland flattened.
||207 to 260 MPH
||Few walls, if any, standing in well-built homes. Large steel and concrete missiles thrown far distances.
||261 to 318 MPH
||Homes leveled with all debris removed. Schools, motels, and other larger structures have considerable damage with exterior walls and roofs gone. Top stories demolished
||Less than 1%
How big are tornadoes?
Most tornadoes are less than 1/4 of a mile wide on the ground - but they can
also can exceed 1 mile in width! The McColl tornado in March 1984 (moving
from the McColl S.C. area into North
Carolina) was over 1 1/2 miles on the ground!
Most tornadoes are on the ground 10
minutes or less - but in 1925 a tornado traveled 219 miles across Missouri,
Illinois, and Indiana in 4 hours!
In 1924, a tornado that started in Aiken
County South Carolina traveled 135 miles into Florence County!
How fast can tornadoes move?
|When are tornadoes most likely?
In the southern
United States the
of tornadoes is March through May - but tornadoes
can occur any time of year!
occur between 3
and 9 PM - but
tornadoes can occur at any time of day or night!
Click to Enlarge Map
|Where is the safest place to take shelter from a tornado...
- In my home?
- Get away from windows
- they may shatter and
glass may go flying
- Go to the basement and
get under a heavy workbench or the stairs
- If you don't have a basement, go to an inside closet, bathroom,
or a hall on the lowest level of the house
- Get under a mattress.
- Protect your head
- In my car?
- Get out of a car and
inside a sturdy house or building!
- Don't try to outrun a
tornado in a car.
- Tornadoes can pick up a car and throw it through the air
- At school?
- Follow directions of your
- Go to an inside hall on the lowest floor
- Crouch near the wall. Bend over with your hands on the back of
- Keep away from glass and stay out of large rooms like the gym,
cafeteria, or auditorium
- Keep a battery radio on
and listen for news about the tornado
- In a mobile home?
- If you live in a mobile
home - get out!
- Even it's it tied down a mobile home can be shattered by a tornado
The entire mobile home can be lifted off the ground and dropped
- Get out and into a safe place. If you can't get to
a tornado shelter, lie in a ditch and cover your head with your hands.
- Downtown or shopping?
- Get off the streets
- Go into a building and stay away from windows and doors
- If I'm caught outside?
- Take shelter in a ditch,
culvert, or ravine
- Cover your head with
Most tornado deaths are the result
of flying debris
1. Areas near rivers, lakes, and mountains are
safe from tornadoes
2. The low pressure with a tornado causes building to "explode" as the tornado passes
3. Windows should be opened before a tornado
approaches to equalize pressure and
1. No place is safe from tornadoes. In the late
1980's, a tornado swept through Yellowstone
National Park leaving a path of destruction up
and down a 10,000 ft mountain.
2. Violent winds and debris slamming into a
building cause most structural damage.
3.Opening windows allows damaging winds to
enter the structure. Leave windows alone;
instead, go immediately to a safe place.
The National Weather Service issues watches and warnings for
| A TORNADO WATCH means conditions are favorable for tornadoes
to develop or move into the watch area. Watches are intended to
heighten public awareness of the possible severe weather threat. Keep
an eye on the sky and stay tuned to NOAA Weather Radio or local radio, television, or cable to know when
severe weather warnings are issued for your area.
A TORNADO WARNING means a
tornado poses an imminent danger to life and property to those in the path
of the storm. When a tornado is indicated by weather radar, or is
reported by trained SKYWARN Severe Weather Spotters or law
enforcement officials a warning is issued immediately.
Tornado Watches and Warnings are sent to local radio and television stations and are
broadcast over your local NOAA Weather Radio serving the warning area. These
warnings are also relayed to local emergency management and public safety officials who
can activate local warning systems to alert communities to the
Contact us if you'd like a free copy of Thunderstorms...Tornadoes...Lightning...Nature's Most Violent
Storms - a preparedness brochure produced by the National Weather Service, Federal Emergency Management Agency, and the American Red Cross.
Related Web Sites on Tornado Safety:
|National Weather Service
Weather Forecast Office Columbia
2909 Aviation Way
West Columbia, S.C. 29170-2102
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