Wind-shear definition

A significant variation in the speed or velocity of the wind with respect to location or altitude, as in the speed change of a downdraft, or in the directional change of lateral winds along the edge of a thunderstorm.

A sudden change in the direction of the wind; esp., a sudden, dangerous downdraft encountered as by aircraft.

A change in wind direction and speed between slightly different altitudes, especially a sudden downdraft. Depending on its scale, wind shear can cause a variety of effects, from minor turbulence to tornadoes. Wind shear caused by interactions between oceanic and atmospheric winds can be so strong that it can dissipate hurricanes.