flash flood

American  

noun

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

---

flash flood British  

noun

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

---

flash flood Scientific  

/ flăsh /

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.

---

Related Words

See flood.

Etymology

Origin of flash flood

First recorded in 1935–40

Example Sentences

Authorities warn that the same storm system is now threatening other islands, with flash flood alerts and evacuation warnings issued for parts of Maui, Molokai and Lanai.

From Salon • Mar. 22, 2026

That’s because an expansive database specific to flash flood trends like this didn’t exist until now.

From The Wall Street Journal • Mar. 12, 2026

Australia's emergency services warned people Friday to stay prepared for sudden downpours and dangerous bushfires in the country's east after a flash flood swept cars into the sea.

From Barron's • Jan. 16, 2026

A flash flood watch is in effect for most of the county from 8 p.m.

From Los Angeles Times • Oct. 14, 2025

As it turned out, the flash flood didn’t have enough power to carry away the vehicle or even to do any lasting damage.

From "Into the Wild" by Jon Krakauer

Related Words

• deluge
• torrent