National Weather Service United States Department of Commerce

Winter Weather Brings Dangerous Travel Conditions Across the Northern U.S.

Heavy lake effect snow will persist downwind of the Great Lakes through early Saturday. Snow squalls with heavy snow and gusty winds will create dangerous travel in the Interior Northeast due to low visibility and slippery roads. A major winter storm will bring moderate to heavy, accumulating snow and gusty winds from the eastern Plains to the western Great Lakes today through Saturday. 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.