# Wind shear

From AMS Glossary

## wind shear

The local variation of the wind vector or any of its components in a given direction.

The vertical shear can be expressed in terms of height ∂

*V*/∂*z*or of pressure ∂*V*/∂*p*as the vertical coordinate. If the wind is geostrophic, the vertical shear is given by the thermal wind equation. The wind shear at a point is said to be cyclonic or anticyclonic according to whether the sense of rotation from the wind vector to the shear vector at that point is cyclonic or anticyclonic.