Tornadoes

A tornado in action Tornadoes are one of the most beautiful things to grace this earth, coming in all different shapes and sizes. They are a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, although the word cyclone is used in meteorology to name a weather system with a low-pressure area in the center around which, from an observer looking down toward the surface of the Earth, winds blow counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.



Science

Main street of Te Puke Tornadoes form within severe thunderstorms, particularly supercells, when a combination of warm, moist air and a change in wind speed and direction with height (wind shear) creates a rotating column of air that extends from the cloud to the ground. The three key ingredients for a tornado to form are:

  1. Warm, Moist Air Near the Ground
  2. Cool, Dry Air Above
  3. Wind Shear