National Weather Service United States Department of Commerce

Catastrophic Flooding Impacts in South-Central Texas

Widespread life-threatening flash and urban flooding will continue to pose a significant threat to life and property in south-central Texas. Catastrophic fiver flooding, with rapid rises on small streams, arroyos, and typically dry washes, is expected. Monsoonal showers persist across the Great Basin and Southwest with greatest flash flooding in southern Arizona. 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.