flash flood

American  

noun

flash floods plural

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

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flash flood British  

noun

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

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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.

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Synonym Usage

See flood.

Other Word Forms

Noun Inflected Forms

• flash floods
  plural

Etymology

Origin of flash flood

First recorded in 1935–40

Example Sentences

On Sunday morning local time, officials began to stand down some evacuation and flash flood warnings on Oahu, but other parts of the state remained under threat.

From BBC • Mar. 22, 2026

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

Google said the Southern African Development Community used the tool to pick up an imminent flash flood in Mozambique.

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

In 1915 the river boiled up in a flash flood, ripping over the shoreline around the factory.

From "Seabiscuit: An American Legend" by Laura Hillenbrand

Related Words

• deluge
• torrent