windshear

Noun

wind shear (countable and uncountable, plural wind shears)

1. (uncountable) Variation in wind speed or direction over a short spatial distance.
   • Wind shear from a microburst, as compared to wind shear resulting from a gust front, is particularly hazardous because it is a short-period event which creates very strong wind gusts with a large variation in direction over a very short distance (1/2 to 2 1/2 miles in diameter).1985 March 21, National Transportation Safety Board, “1.7.3 Weather Analysis”, in Aircraft Accident Report: United Airlines Flight 663, Boeing 727-222, N7647U, Denver, Colorado, May 31, 1984, page 14
2. (countable) A specific instance of variation in wind speed or direction over a short spatial distance.
   • The first effect of a wind shear was detected at 34 to 42 seconds into the takeoff, at a speed of about 115 KIAS with the airplane about 3,800 feet down the runway. An average shear rate of about 2.5 knots per second resulted in an interruption in acceleration at this point with the airspeed...1985 March 21, National Transportation Safety Board, “2.3 Airplane Takeoff Performance”, in Aircraft Accident Report: United Airlines Flight 663, Boeing 727-222, N7647U, Denver, Colorado, May 31...