National Weather Service United States Department of Commerce

Atmospheric River Continues Areas of Heavy Rain and Snow for California This Weekend

An atmospheric river will continue to bring gusty winds, moderate to heavy rainfall, and potential flooding to southern California and the southern Great Basin through Sunday. Periods of heavy snow will continue as well above 7,000 feet over the Sierra Nevada mountains associated with this atmospheric river. Read More >

12-hour helicity forecast

 

Figure 5: ETA 12 Hour Forecast of 300 K isentropic surface,
wind and relative humidity valid 1200 UTC May 12, 1997.

 

18-hour helicity forecast

 

Figure 6: ETA 18 Hour Forecast of 300 K isentropic surface,
wind and relative humidity valid 1800 UTC May 12, 1997.