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 TORNADOES
A tornado is a violent
windstorm characterized by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm and is produced when cool air overrides a layer of
warm air, forcing the warm air to rise rapidly. The damage from a tornado is a result of
the high wind velocity and wind-blown debris. Tornado season is generally March through
August, although tornadoes can occur at any time of the year. They tend to occur in the
afternoons and evenings: over 80 percent of all tornadoes hit between noon and midnight.
When a tornado is coming, you have
only a short amount of time to make life-or-death decisions. Advance planning and quick
response are the keys to surviving a tornado.
1. The best protection during a
tornado is on the lowest level of a building, preferably a basement or storm celler.
2. Tornadoes strike with
incredible velocity. Wind speeds may approach 300 miles per hour. These winds can uproot
trees and structures and turn harmless objects into deadly missiles, all in a matter of
seconds. Mobile homes are particularly vulnerable to tornadoes.
3. Injuries or deaths related to
tornadoes most often occur when buildings collapse, people are hit by flying objects, or
are caught trying to out-drive the twister in a car.
4. Tornadoes are most destructive
when they touch ground. Normally, a tornado will stay on the ground for no more than 20
minutes; however, one tornado can touch ground several times in different areas.
BEFORE
Conduct tornado drills
each tornado season. Designate an area in the home as a shelter, and practice having
everyone in the family go there in response to a tornado threat.
Discuss with family members the difference
between a "Tornado Watch" and a "Tornado Warning". Learn the tornado
signs.
TORNADO WATCHES AND WARNINGS
A tornado watch
is issued by the National Weather Service when weather conditions are such that tornadoes
are likely to develop.
This is the time to remind family members
where the safest places within your home are located, keep alert for changing weather
conditions, and listen to the radio or television for further developments.
A tornado warning
is issued when a tornado has been sighted or indicated by radar. At this point, the danger
is very serious and everyone should go to a safe place, turn on a battery-operated radio
or television, and wait for the "all- clear" from the authorities.
TORNADO DANGER SIGNS
Large hail: Tornadoes are spawned from
powerful thunderstorms and the most powerful thunderstorms produce large hail. Tornadoes
frequently emerge from near the hail- producing portion of the storm.
Calm before the storm: Before a
tornado hits, the wind may die down and the air may become very still.
Cloud of debris: An approaching
cloud of debris can mark the location of a tornado even if a funnel is not visible.
Funnel cloud: A visible rotating
extension of the cloud base is a sign that a tornado may develop. A tornado is evident
when one or more of the clouds turns greenish (a phenomenon caused by hail) and a dark
funnel descends.
Roaring noise: The high winds
of a tornado can cause a roar that is often compared to the sound of a freight train.
Calm behind the storm: Tornadoes
generally occur near the trailing edge of a thunderstorm. It is not uncommon to see clear,
sunlit skies behind a tornado. 
Did you know?
Tornadoes
can occur in any state, but are more frequent in the Midwest, Southeast and Southwest. The
States of Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana,
Mississippi, Missouri, Nebraska, Oklahoma, South Dakota, and Texas are at greatest risk.
D U R I N G
IF AT HOME:
Go, at once, to the
basement, storm cellar, or lowest level of the building. If there is no basement, go to an
inner hallway or a small inner room without windows, such as a bathroom or a closet.
Get away from windows. Go to the center of
the room. Stay away from corners because they tend to attract debris. Get under a piece of
sturdy furniture, such as a workbench or heavy table, and hold on to it. Use arms to
protect head and neck.
IF AT WORK OR SCHOOL:
Go to the basement or to an inside hallway at
the lowest level. Avoid wide rooms such as auditoriums, cafeterias, or large hallways. Get
under a piece of sturdy furniture, such as a workbench or heavy table or desk, and hold on
to it. Use arms to protect head and neck.
IF OUTDOORS:
Never try to out-drive a tornado in a car or
truck. Tornadoes can change directions quickly and can lift up a car or truck and toss it
through the air. Get out of the car immediately and take shelter in a nearby building. If
there is no time to get indoors, get out of the car and lie in a ditch or low-lying area
away from the vehicle.
MOBILE HOMES
Mobile homes are particularly vulnerable. A
mobile home can overturn very easily even if precautions have been taken to tie down the
unit. When a tornado warning is issued, take shelter in a building with a strong
foundation. If shelter is not available, lie in a ditch or low-lying area a safe distance
away from the unit.
A F T E R
Check for injured
or trapped persons. Give first aid when appropriate. Don't try to move the seriously
injured unless they are in immediate danger of further injury. Call for help.
Turn on radio or television to get the
latest emergency information.
Use the telephone only for emergency calls.
Clean up spilled medicines, bleaches, gasoline, or other flammable liquids immediately.
Leave the building if you smell gas or chemical fumes. Stay out of damaged buildings.
Return home only when authorities say it is safe.
"OPEN
WINDOW" MYTH
Many people mistakenly believe they should open a window when a tornado is coming. They
believe that since houses are airtight, the change in air pressure during a tornado could
cause a home to explode. Actually, buildings are not airtight. They leak, equalizing air
pressure naturally. Opening a window allows the strong winds to enter, cause damage, and
increase the possibility of injury. |
DID YOU KNOW...
Tornadoes can be nearly invisible, marked only by swirling debris
at the base of the funnel. Some are composed almost entirely of windblown dust and still
others are composed of several mini-funnels.
On average, the United States experiences 100,000 thunderstorms each year. Approximately
1,000 tornadoes develop from these storms.
Although tornadoes do occur throughout the world, the United States experiences the most
intense and devastating tornadoes.
Tornadoes produce the most violent winds on earth. Tornado winds can approach speeds as
high as 300 miles per hour, travel distances over 100 miles and reach heights over 60,000
feet above ground.
According to the National Weather service, about 50 people are killed because of
tornadoes each year.
Fujita - Pearson Tornado
Scale
F-0:
40-72 mph, chimney damage, tree branches broken
F-1:
73-112 mph, mobile homes pushed off foundation or overturned
F-2:
113-157 mph, considerable damage, mobile homes demolished, trees
uprooted
F-3: 158-205 mph, roofs and walls torn down, trains overturned, cars thrown
F-4:
207-260 mph, well-constructed walls leveled
F-5:
261-318 mph, homes lifted off foundation and carried considerable distances, autos thrown
as far as 100 meters |
 
Although tornadoes occur in many parts of the world, these destructive forces of
nature are found most frequently in the United States east of the Rocky Mountains during
the spring and summer months. In an average year, over 800 tornadoes are reported
nationwide, resulting in 50 deaths and over 1,500 injuries. A tornado is defined as a
violently rotating column of air extending from a thunderstorm to the ground. The most
violent tornadoes are capable of tremendous destruction with wind speeds of 250 mph or
more. Damage paths can be in excess of one mile wide and 50 miles long. Once a tornado in
Broken Bow, Oklahoma, carried a motel sign 30 miles and dropped it in Arkansas.
Worst Twisters Recorded in US History
- May 31, 1985:
90 killed in Ohio, Pennsylvania and Ontario.
April 3-4, 1974: More than 300 killed in "super
outbreak" of 148 tornadoes in 11 Midwest states.
Feb. 21, 1971: 110 killed in Mississippi Delta region.
April 11, 1965: 271 killed in Indiana, Illinois, Ohio, Michigan and Wisconsin.
May 25, 1955: 115 killed in Kansas, Missouri, Oklahoma and
Texas.
June 9, 1953: 90 killed in Worcester, Mass., area.
June 8, 1953: 142 killed in Michigan and Ohio.
May 11, 1953: 114 killed in Waco, Texas, area.
March 21, 1952: 208 killed in Arkansas, Missouri and Texas.
April 9, 1947: 169 killed in Texas, Oklahoma and Kansas.
June 23, 1944: 150 killed in Ohio, Pennsylvania, West Virginia and Maryland.
April 6, 1936: 203 killed at Gainesville, Ga.
April 5, 1936: 216 killed at Tupelo, Miss.
March 21, 1932: 268 killed in Alabama.
March 18, 1925: 689 killed in Missouri, Illinois and Indiana.
May 18, 1902: 114 killed at Goliad, Texas.
May 27, 1896: 300 killed in Missouri and Illinois.
Feb. 19, 1884: More than 800 killed in Mississippi, Alabama,
North and South Carolina, Tennessee, Kentucky and Indiana.
May 6, 1840: 317 killed in Natchez, Miss.
Frequency of Tornadoes
- Tornadoes can occur at any time of the year.
- In the southern states, peak tornado occurrence is in March
through May, while peak months in the northern states are during the summer.
- Note, in some states, a secondary tornado maximum occurs in the
fall.
- Tornadoes are most likely to occur between 3 and 9 p.m. but have
been known to occur at all hours of the day or night.
- The average tornado moves from southwest to northeast, but
tornadoes have been known to move in any direction. The average forward speed is 30 mph
but may vary from nearly stationary to 70 mph.
- The total number of tornadoes is probably higher than indicated in
the western states. Sparce population reduces the number reported.
Rank |
Total
numbers of tornadoes |
Deaths
per 10,000 sq miles |
Number
of killer tornadoes |
Total
tornado path length per 10,000 sq miles |
Killer
tornadoes as a % of all tornadoes |
Annual
tornadoes per 10,000 sq. miles |
1 |
Texas |
Massachusetts |
Texas |
Mississippi |
Tennessee |
Florida |
2 |
Oklahoma |
Mississippi |
Oklahoma |
Alabama |
Kentucky |
Oklahoma |
3 |
Florida |
Indiana |
Arkansas |
Oklahoma |
Arkansas |
Indiana |
4 |
Kansas |
Alabama |
Alabama |
Iowa |
Ohio |
Iowa |
5 |
Nebraska |
Ohio |
Mississippi |
Illinois |
Alabama |
Kansas |
6 |
Iowa |
Michigan |
Illinois |
Louisiana |
Mississippi |
Delaware |
7 |
Missouri |
Arkansas |
Missouri |
Kansas |
North
Carolina |
Louisiana |
8 |
Illinois |
Illinois |
Indiana |
Indiana |
Michigan |
Mississippi |
9 |
South
Dakota |
Oklahoma |
Louisiana |
Nebraska |
New
York |
Nebraska |
10 |
Louisiana |
Kentucky |
Tennessee |
Wisconsin |
Massachusetts |
Texas |
This site is provided by the Bainbridge Township Fire Department for the
community that we faithfully serve.
Please contact Asst.
Chief Bill Lovell with any bugs, comments or suggestions for
improvement so that we can make this site more beneficial.
Last Revision: 11/05/04  |
