A miniature cold front created by the downdraft of a large thunderstorm as the dense, rain-cooled air spreads outward beneath the thunderstorm. Gust fronts can produce strong, gusty, damaging surface winds, and often serve as a triggering mechanism for new thunderstorms.
The front created when downdraft or downburst air reaches the ground and spreads out. These have been observed to be 100 to 1000 m deep, 5 to 100 km wide, last for 2 to 20 minutes, and spread with speeds of 5 to 15 m/s. Gust fronts are also capable of triggering new thunderstorms as the air in the boundary layer is forced to rise over the advancing front.
A boundary found ahead of a thunderstorm that separates cold storm downdrafts from warm humid surface air. Winds in this phenomenon are strong and fast.