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Flash Flood vs. Flood Warning: How it’s defined and what you need to know

Know the difference

HOUSTON – Here’s what to know about floods and flash flooding:

Flash Flood

Flooding caused by the rapid rise of water in rivers, creeks, other waterways, or urban/developed areas as a result of intense rainfall over a small area. Flash flooding usually happens within minutes to several hours after a heavy rainfall event.

Flash Flood Watch

An announcement is issued when conditions are favorable for flash flooding. It does not mean that flash flooding will occur, but it is possible.

Flash Flood Warning

A warning is issued when flash flooding is imminent or occurring.

Flood

Overflowing of a stream or other body of water. Or, the accumulation of water over areas that are not normally submerged.

Flood Watch

An announcement is issued when conditions are favorable for flooding. It does not mean flooding will occur, but it is possible.

Flood Warning

A warning is issued when flooding is imminent or occurring.