Transcript Tornadoes

Tornadoes
What is a Tornado?

A tornado is a
violent rotating
column of air
extending from
a thunderstorm
to the ground.
How do Tornadoes Form

Warm moist air comes North from the
Gulf of Mexico and collides with Cool
Dry air from Canada.
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There is a large difference in temperature
and moisture between the masses.
Meeting masses create instability in the
atmosphere.
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Rising air within the updraft tilts the
rotating air from horizontal to vertical
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A larger pressure difference will indicate
faster speeds and more energy of a tornado.
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An average tornado will be 400 to 500
feet wide and travel four or five miles
on the ground, lasting only a few
minutes
When are tornadoes likely to
occur?

3pm – 9pm are likely times of day

Surface heating creates maximum number
of convection currents in the atmosphere
March-May for southern states
 Summer months for northern states
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Warm air masses are more likely from the
Gulf of Mexico during this time.
Where are Tornadoes Likely to
form?

Tornado alley is in an area of the great
plains, East of the Rocky mountains.
(cP air masses mix with mT air masses)
Fujita Scale of Tornado
Intensity
Dangers of Tornadoes
Tornadoes may have a diameter of 2-3
km.
 Wind speeds range from 40-318 mph
 Hail stones can be generated
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Tornado Damage
Spotting a Tornado

There is typically a
distinctive hook
found on Doppler
radar.
Warning systems
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Tornado Watch:
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Issued to alert people to the possibility of
tornado development in your area
Tornado Warning:
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Issued when a tornado has actually been
sighted or is indicated by radar.