Flash flood emergency alerts are issued for potentially destructive and life-threatening flooding that is imminent or ongoing.
Here are three things to know about these very serious alerts issued by the National Weather Service, and what you should do if you are in an warned area.
1. It's The Highest Level Of Flood Alert
It's important to understand the differences between flash flood warnings and emergencies.
Flash flood warnings are common: The NWS issues these by the thousands each year. Typically, at least some streets and roads will be flooded in areas covered by a flash flood warning, which can be dangerous for motorists. Some of these warnings cover events in which a few low-lying properties have taken on some water.
Flash flood emergency warnings are rare: Given the large number of flash flood warnings issued, just over 20 years ago the NWS began issuing a more extreme alert, called a flash flood emergency, to highlight rare occasions when there is a major threat to life or potential for catastrophic damage.
When issued, these flash flood emergencies are embedded within existing flash flood warnings, specifically as a headline near the top of the warning. They can cover parts of one or more counties, like the example below from Virginia in August 2025.
2. The Triggers For A Flash Flood Emergency
According to NWS guidelines, these are the situations that may trigger a flash flood emergency:
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A local or state emergency manager has confirmed that rapidly rising water is placing, or will place, people in a life-threatening situation.
Water is expected, or has already rapidly risen, to levels where people in typically safe locations during other flash flood events will be in danger. These include cases where water could encroach several feet above floor level in a home, requiring rescue and putting the entire home at risk.
Several swift-water rescue teams have been deployed to a flash flood of unusual magnitude.
River and stream gauges indicate water has risen to at least major or rarely seen flood levels.
A complete failure of a large, high-hazard dam is possible that would have a catastrophic impact on downstream areas.
This is a similar concept totornado emergencies, which are issued in cases where catastrophic damage and a severe threat to life is imminent or ongoing with a confirmed tornado.
3. Actions You Should Take
This highest flash flood alert will trigger your smartphone to screech loudly, known as a wireless emergency alert.
If you're in a flash flood emergency zone:
Move to higher ground immediately.
Do not travel unless you're either escaping a flooded area or are ordered to evacuate by local officials.
Avoid walking or driving through any flood water. You may not be able to tell how deep the water is and the road underneath could have been washed out. Even slow-moving water can knock you off your feet or float your vehicle, sweeping you away downstream.
(MORE:Never Drive Through A Flooded Road. Your Vehicle Can Be A Trap.)
The bottom line: if you are in an area that has recently been placed in a flash flood emergency, do not travel and seek higher ground immediately. The National Weather Service uses these emergencies sparingly, so take them very seriously.