Definition
WS is the standard contraction used in aviation weather products and reports to indicate wind shear — a sudden change in wind speed and/or direction over a short distance in the atmosphere, either horizontally or vertically.
Plain English
WS is shorthand for wind shear, meaning the wind changes speed or direction quickly across a small piece of sky.
Context Anchor
Seen in aviation weather reports, forecasts, pilot reports, and cockpit discussions about takeoff, approach, and landing conditions.
Derivation
Simply the first letters of Wind Shear. Aviation weather codes are deliberately compressed so they fit into short text reports transmitted between stations and pilots.
Why Pilots Care
Wind shear can produce abrupt airspeed and altitude changes that reduce aircraft performance and control, especially close to the ground.
Grounding Statement
Picture an airplane on final approach flying from a steady headwind into a sudden weaker wind; the airplane can lose lift and sink faster than expected.
Example Sentence 1
The TAF included a WS line warning of low-level wind shear below 2,000 feet during the arrival window.
Example Sentence 2
The crew executed a go-around after encountering wind shear at 300 feet AGL.