What is a tornado

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What is a tornado?

• A tornado is a violent whirling wind that moves
  across the ground in a narrow path.
  

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How are Tornadoes formed?

• Late in the day, when earths surface is very
  warm, convection (The flow of heat through a
  material, causing hot parts to rise and cooler
  parts to sink.) can get very strong. This can
  lead to a tornado.

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• A tornado is a sort of a runaway convection
  cell.
  
• A convection cell is a circular pattern of air
  rising, air sinking and wind.
  

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Tornado Happenings

• 1.When the updraft in a convection cell is really
  strong, the air rushes in from all sides at high
  speeds.

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• 2. Air curves into a spin. This lowers the
  pressure even more. Air rushes in even faster,
  and the pressure gets even lower, and so on.
  
• Like a skater who pulls her arms in close to her
  sides. The tornado spins faster and faster.

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• 3. As the tornado gets stronger, a funnel forms
  that can destroy anything in its path. The
  center of the tornado can reach speeds of 500
  kilometers per hour (about 300 miles per hour) or
  more.

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Where Do Tornadoes Happen?

• Tornadoes happen where dry, cold air masses mix
  with warm, moist air masses.
  
• More tornadoes occur in the United States than in
  any other country, especially in the area known
  as TORNADO ALLEY.

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A Famous Tornado

• Grand Island, Nebraska
• June 3, 1980

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• On June 3, 1980, a series of tornadoes devastated
  the city of Grand Island, Nebraska. Seven
  tornadoes hit within a three hour period. The
  storm did massive damage and closed the city down
  for three days.

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