Plain English Meaning
The wind suddenly starts blowing from a noticeably different direction in a short period of time. Pilots watch for this because it changes how an aircraft handles, especially during takeoff and landing.
Full Definition
A change in wind direction of 45 degrees or more in less than 15 minutes, with sustained wind speeds of 10 knots or more throughout the change. Wind shifts are commonly associated with the passage of frontal systems and can occur with or without a change in wind speed.
Context Anchor
Seen in weather discussions, preflight planning, runway selection, and landing decisions when changing weather may alter the wind direction.
Why Pilots Care
A wind shift can alter crosswind components, require a runway change, or affect .