A Flash Flood Emergency is the highest level of alert issued by the National Weather Service (NWS) for flash flooding, signaling an exceedingly rare and immediate threat. This designation is reserved for situations where catastrophic damage and a severe danger to human life are occurring or are about to happen, requiring immediate, life-saving action.
The Highest Alert Level
The distinction between a Flash Flood Warning and a Flash Flood Emergency is centered on the level of threat to life and property. A standard Flash Flood Warning is issued when dangerous flash flooding is happening or will happen soon, often implying a threat to property and potential danger. The Emergency, however, is an enhanced alert, comparable in seriousness to a Tornado Emergency, and is not issued lightly. This elevated status in the NWS Impact-Based Warning system carries a “Catastrophic” damage tag, activating all public alerting systems, including Wireless Emergency Alerts on mobile phones.
Specific Triggers for Declaration
The NWS elevates an alert to a Flash Flood Emergency based on specific, quantifiable conditions that demonstrate the flood’s catastrophic potential. One primary trigger is the observation of extreme rainfall rates that lead to rapid, significant water rise in densely populated or urban areas, often confirmed by radar data or reports from emergency management officials.
Another trigger is the confirmed or imminent failure of a major water-retaining structure, such as a dam or levee breach, which unleashes a sudden, massive surge of water. The declaration can also be made when water has already risen to devastating levels, placing people in life-threatening situations. These include situations where water is confirmed to be entering the first floor of homes or businesses, necessitating water rescues.
Immediate Safety Protocols
Upon receiving a Flash Flood Emergency alert, the public must take immediate, decisive action to move to the highest ground possible. The universal instruction in any flood scenario is to “Turn Around, Don’t Drown.” Never attempt to walk or drive through floodwaters, as the danger is often underestimated.
It only takes six inches of fast-moving water to sweep an average adult off their feet, making walking through even shallow floodwaters extremely risky. Furthermore, as little as twelve inches of rushing water can carry away most small cars, and two feet can float and sweep away large vehicles, including trucks and SUVs.
If you are inside a building, move to a higher floor immediately, avoiding all basements and low-lying areas. If you are trapped in a vehicle and water is rising rapidly, abandon the car immediately and seek higher ground, as most flood deaths occur inside vehicles. If higher ground is not accessible inside a structure, move onto the roof to await rescue, and remain aware of potential hazards like downed power lines and electrical currents that can travel through water.