Tornadoes
What is a Tornado?
• A tornado is a violently rotating column of air
that usually touches the ground.
• A tornado is a thunderstorms most destructive
possible byproduct.
• Tornado Video
Tornado Formation
• Tornadoes and their paths are very difficult to
predict.
• Scientists have tried to predict tornados by
using instruments to detect them.
• They found it difficult to do so without
damaging the instruments and hurting people.
• Tornadoes are sometimes referred to as a
twister.
Tornado Formation Continued
• Scientists have found in order for a
thunderstorm to produce a tornado it must
contain a rotating updraft called a
mesocyclone.
• A mesocyclone occurs when low altitude
winds blow at different speeds and different
directions than winds higher up.
• Only a third of mesocyclones produce
tornadoes.
Fujita Scale
• The Fujita Scale is used to rate tornado intensity.
• Tornadoes are rated from F-0 to F-5 with an F-5
being the worst.
• The Fujita Scale was created by the man Ted
Fujita in 1971.
• Since than, meteorologists have modified this
scale and tornadoes are now ranked by
“Enhanced Fujita” (EF-0 to EF-5)
• The difference between the two is the enhanced
fujita scale has modified wind speeds in each
category.
Fujita Scale Continued
Tornado Chasers
• Tornado chasers are teams of meteorologists
that chase tornadoes in either regular cars or
in special vehicles that have instruments on
them to gather data from the tornado.
• Some are volunteer chasers who do it for their
own interest and others are hired by the
national weather service to gather data about
tornados.
Tornado Chasers
•One of the most
popular teams of
storm chasers is
the TIV team.
•They use an
armored vehicle
capable of driving
directly through
strong tornados
to gather data
and take video of
inside the
tornado.
Tornado Watches and Warnings
• The national weather service lets people know ahead
of time if a thunderstorm or tornado is going to arrive.
• During this time people should find shelter.
• A severe thunderstorm is one that has wind gusts of at
least 80km per hour, hail at least 2cm in diameter or
funnel cloud or a tornado.
• Meteorologists issue a thunderstorm watch, if
conditions are such that a tornado may form, they
issue a tornado watch.
• In many communities a siren will sound to warn
people.
Safety Precautions
• During a Tornado Watch:
• You should move cars inside a garage. Keep your car
keys and house keys with you.
• Move lawn furniture and yard equipment such as
lawnmowers inside.
• Stay together at home.
• Have your emergency kit ready.
• Keep your radio or TV tuned into the weather reports.
• Go to your basement, or safest area In your home.
Quiz
1. What is a tornado?
A. Storms with lightning, thunder, and rain
B. A discharge of electricity from a thundercloud to
the ground
C. A violently rotating column of air that usually
touches the ground
Quiz
2. Scientists have discovered that for a severe
thunderstorm to produce a tornado, it must
contain a rotating updraft called a….
A. Wall cloud
B. Mesocyclone
C. Lightning
Quiz
3. Only ___ of all mesocyclones produce
tornadoes.
A. One-third
B. 50 %
C. One-fourth
Quiz
4. The Fujita Scale is used to….
A. Measure distance
B. Measure the intensity of the tornado
C. Measure how long a tornado lasts
Quiz
5. If a tornado warning is issued you should find
shelter.
A. True
B. False