National Weather Service United States Department of Commerce

Severe Weather in the Central Plains; Heavy Rainfall in the Tennessee Valley; Critical Fire Weather in the West

Scattered severe storms capable of large to very large hail, severe wind gusts, and a few tornadoes will be possible across the central Plains this evening. Heavy to excessive rainfall may bring a flooding threat from the Great Lakes to the Mid-South through tonight. Hot, dry and windy conditions will continue to bring a critical fire weather threat from the Southwest into the Great Basin. Read More >

 

Definitions of Flood and Flash Flood


Flood: An overflow of water onto normally dry land. The inundation of a normally dry area caused by rising water in an existing waterway, such as a river, stream, or drainage ditch. Ponding of water at or near the point where the rain fell. Flooding is a longer term event than flash flooding: it may last days or weeks.
 
Flash flood: A flood caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours. Flash floods are usually characterized by raging torrents after heavy rains that rip through river beds, urban streets, or mountain canyons sweeping everything before them. They can occur within minutes or a few hours of excessive rainfall. They can also occur even if no rain has fallen, for instance after a levee or dam has failed, or after a sudden release of water by a debris or ice jam.