flash flood

noun

1. a sudden and destructive rush of water down a narrow gully or over a sloping surface, caused by heavy rainfall.

noun

1. a sudden short-lived torrent, usually caused by a heavy storm, esp in desert regions

1. A sudden, localized flood of great volume and short duration, typically caused by unusually heavy rain in a semiarid area. Flash floods can reach their peak volume in a matter of a few minutes and often carry large loads of mud and rock fragments.