National Weather Service United States Department of Commerce

Flash Flood Guidance


Flash Flood Guidance is an estimate of the amount of rainfall required over a given area during a given duration to cause small streams to flood. These estimates are based on the current soil moisture and stream flow conditions for the area. Flash Flood Guidance is routinely issued by National Weather Service (NWS) River Forecast Centers, and is used by NWS Weather Forecast Offices when issuing Flash Flood Watches and Warnings to the public. Note: Less rainfall is required to produce flash flooding in urban areas.




3-hour Flash Flood Guidance Graphic. Click on image to go to an interactive page.


Additional Flash Flood Guidance Graphics


Flash Flood Guidance Text Products




Eastern Illinois


Western New York

Western Pennsylvania


Western Virginia

West Virginia