CW3E AR Update: 10 January 2023 Outlook

January 10, 2023

Click here for a pdf of this information.

Increased Atmospheric River Activity Forecast to Continue over California during the next 7–10 days

  • A strong atmospheric river (AR) made landfall Sunday night, resulting in very heavy rainfall and flooding in portions of Central and Southern California
  • This episode of increased AR activity across the Western U.S. is forecast to continue with four additional ARs predicted to make landfall over the next week
  • The first AR will bring long duration and southerly AR conditions to a portion of the North-Coast tomorrow into Friday
  • The storm track is forecast to shift southward as two additional ARs are forecast to make landfall over Central California on Saturday and Sunday
  • A fourth AR is then forecast to make landfall next week over Northern California, though there is large forecast uncertainty associated with this fourth AR
  • The NOAA Weather Prediction Center has issued a slight risk for precipitation to exceed flash flood guidance where the first AR is forecast to extend inland for several days
  • Large model-to-model uncertainty in precipitation forecasts currently exists over the Russian River watershed as any slight shift in the location of the first AR will result in large differences in AR magnitude and duration
  • Stay alert to official NWS forecasts, watches, and warnings at and follow guidance from local emergency management officials

Click images to see loops of GFS IVT and IWV forecasts

Valid 1200 UTC 10 January – 1200 UTC 18 January 2023











Summary provided by C. Hecht, C. Castellano, S. Bartlett, J. Kalansky, and F. M. Ralph; 10 January 2023

To sign up for email alerts when CW3E post new AR updates click here.

*Outlook products are considered experimental