A strong wind with sudden onset and more gradual decline, lasting for several minutes. Wind speeds in squalls commonly reach 30–60 mi/h (13–27 m/s), with a succession of brief gusts of 80–100 mi/h (36–45 m/s) in the more violent squalls. Squalls may be local in nature, as with isolated thunderstorms, or may occur over a wide area in the vicinity of a well-developed cyclone, where the squalls locally reinforce already strong winds. Because of their sudden violent onset, and the heavy rain, snow, or hail showers which often accompany them, squalls cause heavy damage to structures and crops and present severe hazards to transportation.