Plain English Meaning
A fast change in the wind close to the ground, where the wind direction or strength shifts sharply over a short distance. Because it happens low down, the aircraft has little altitude to recover if it loses lift or airspeed.
Full Definition
A sudden change in wind speed and/or direction over a short distance occurring at or below 2,000 feet above ground level. It can produce rapid gains or losses of airspeed and abrupt vertical movement of the aircraft, and is most hazardous during takeoff, initial climb, approach, and landing.
Context Anchor
Pilots encounter this term in weather briefings, airport , , and training on in gusty or stormy .