National Weather Service United States Department of Commerce

Heat and Fire Weather Concerns in the West; Excessive Rainfall Possible in the South-Central U.S.

Heat will build over the Intermountain West and the Southwest the next couple of days. Lightning from dry thunderstorms can create new fire starts and combined with gusty winds may cause a fire to rapidly grow in Oregon and northern California. Flash flooding will be possible in Arizona and west Texas today, as well as parts of the southern and central Plains due to slow moving thunderstorms. 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.