National Weather Service United States Department of Commerce

Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Balloons are released by NWS Flagstaff meteorologists twice a day (around 4am and 4pm) to measure the pressure, temperature, dewpoint, and winds through the atmosphere. For more information about the NWS upper-air program and to learn how to read the plot below, click here.

Click here to view upper-air soundings from other areas around the continental United States.


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