CW3E AR Update: 2 November 2022 Outlook

November 2, 2022

Click here for a pdf of this information.

Strong Atmospheric River to Impact Washington and Oregon

• A strong atmospheric river will make landfall along the coast of British Columbia and slide south along the coast of Washington and Oregon, bringing AR3/AR4 (based on the Ralph et al. 2019 AR Scale) conditions to the area
• The AR is also forecast to bring AR2/AR3 conditions to locations east of the Cascades in interior Washington and Oregon
• The NWS Weather Prediction Center is forecasting more than 5 inches of total precipitation in portions of western Washington and Oregon over the next 5 days
• There are significant differences in forecast precipitation between the 00Z GFS and 00Z ECMWF, with the GFS showing a stronger rain shadow effect east of the Olympic Mountains and Cascades
• High freezing levels will limit snowfall accumulations below 7,000 ft, but strong uplsope moisture flux and inland penetration of the AR will likely produce significant snowfall in the higher terrain of the North Cascades and Northern Rockies
• Precipitation from this storm will bring favorable conditions for debris flows in areas of Washington and Oregon with burn scars from recent fire seasons
• As part of CW3E’s Atmospheric River Reconnaissance program, this event will be sampled by the 53rd Weather Reconnaissance Squadron on 3 November, feeding meteorological data into the global forecast models

Click images to see loops of GFS IVT & IWV forecasts Valid 1200 UTC 2 November – 1800 UTC 6 November 2022

Summary provided by S. Bartlett, C. Castellano, S. Roj, J. Kalansky, C. Hecht, B. Kawzenuk and F. M. Ralph; 2 November 2022

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

*Outlook products are considered experimental