n. a violently whirling column of air with wind of 100-300 miles
per hour, extending downward from a cumulonimbus cloud in Australia and the
central United States: almost always seen as a rapidly rotating, slender,
funnel-shaped cloud that usually destroys everything along its narrow path.
Tornadoes are violent windstorms exceeding
300 miles per hour. A very powerful tornado can pick up cattle, automobiles, and
even sometimes pick up mobile homes into the air. Thankfully, most tornadoes are
weak and not as devastating. A tornado is considered a cyclone.
A cyclone refers
to all spiral
shaped windstorms that go clock-wise in the Southern Hemisphere
and counter-clock-wise in the Northern Hemisphere. Cyclone is the Greek
word for circle. For a tornado to develop, the winds at higher elevation
must combine with the winds at a lower elevation. Such a difference of
temperature is called a wind shear. The wind shear makes the rising
column of air begin to rotate, forming a large, horizontal tube of swirling air.
As the storm continues, this tube turns on end, forming a rotating column of air
called a mesocyclone. A low, dark, heavy cloud called a wall cloud forms
beneath the mesocyclone. A funnel develops out of the wall cloud forming the
tornado. There is always lots of damage done by a tornado, but repairs can be made.