GUST

in meteorology, a sudden wind-speed increase of 4.6 m per second (10.3 miles per hour) or more, to a peak speed of 8 m per second (about 18 miles per hour) or more. It is briefer than a squall and usually lasts 20 seconds or less. Air turbulence around an obstacle causes gusts; they occur frequently over buildings and irregular ground and are generally absent over water. The term gust also denotes a sudden change in wind speed relative to a flying aircraft.