Heavy rain can overwhelm the ground’s ability to absorb water in a matter of minutes or hours. The sudden local overflow is a flash flood. These events are especially dangerous because they develop with little warning and can turn dry channels into raging torrents.

Steep terrain, burned hillsides, and urban areas with extensive pavement all increase the risk. A thunderstorm that stalls or repeatedly trains over the same area is a common trigger. Water levels can rise several feet in a short time, sweeping away vehicles and damaging buildings.

Warnings rely on radar estimates of rainfall rates, stream gauges, and spotter reports. The advice is simple: move to higher ground immediately and never attempt to drive through flooded roadways. Many fatalities occur when people underestimate the power of moving water.

Recovery often involves clearing debris and repairing infrastructure after the water recedes.