CW3E AR Update: 20 November Outlook

November 20, 2018

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Update on the ARs forecast to Impact California this Week

• Forecast confidence within the GEFS has continued to increase for the two ARs forecast to impact CA over next few days
• There is potential for development of a mesoscale frontal wave associated with AR 2, which could lead to stalling of the AR
• NOAA WPC 1–3 day precipitation forecasts are as high as 5–7 inches over the N. CA Coastal Mountains and N. Sierra
• The precipitation may bring much needed relief to the currently active fires and smoky conditions over CA
• While precipitation will bring relief from the currently active fires and smoke across California, there is the potential for high precipitation rates, which are conducive to the triggering of debris flows

Click IVT or IWV image to see loop of 0-102 hour GFS forecast Valid 1200 UTC 20 November – 1800 UTC 24 November 2018

Summary provided by C. Hecht, F. M. Ralph, B. Kawzenuk, J. Kalansky; 3 PM PT 20 November 2018

*Outlook products are considered experimental