Wind shear

difference in wind speed or direction over a short distance

Wind shear is a difference in either wind speed or direction over a fairly short distance in the atmosphere. Wind shear can be divided into two different types: horizontal and vertical wind shear.

NASA schematic of the downward motion of the air until it hits ground.

When wind shear is observed

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Weather situations when the Wind shear is observed happen:

  • At weather fronts when the temperature difference across the front is 5 °C or more, and the front moves at 15 kt or faster.
  • At low level jets when a significant low level vertical wind shear can develop near the lower portion of the low level jet.
  • At mountains when winds blow over and create vertical shear on the lee side.[1]
  • At inversions when on a clear and calm night a radiation inversion is formed near the ground.
  • At downbursts when an outflow boundary moves away from a thunderstorm.
  • At sailing when wind shear affects sailboats by presenting a different wind speed and direction at different heights along the sailing mast.
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  1. National Center for Atmospheric Research. T-REX: Catching the Sierra’s waves and rotors Archived 2009-02-21 at the Wayback Machine Retrieved on 2006-10-21.

Other websites

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