Tracking Atmospheric River for the West Coast; Space Weather Storming Continues

An atmospheric river will bring threats of gusty to high winds and heavy rainfall to California mainly Thursday into Saturday which may bring areas of flooding and wind damage. Heavy snow will be possible over the Sierra Nevada mountains Thursday into Friday associated with the atmospheric river. Minor to severe geomagnetic storming (space weather) is expected to continue into early Thursday. 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.

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