CW3E AR Update: 10 September 2020 Outlook

September 10, 2020

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A Landfalling Atmospheric River is Forecast to Potentially Bring Wildfire Relief to the Pacific Northwest

  • An AR that is forecast to make landfall early next week could bring much needed precipitation to parts of Washington, Oregon, and potentially Northern California.
  • Due to large lead times in the forecasts, there is currently very large ensemble and model-to model uncertainties in AR conditions, magnitude, duration, and location.
  • The large forecast uncertainties make it difficult to pinpoint where beneficial and wildfire relieving rains could fall
  • The NOAA Weather Prediction Center is currently predicting as much as 2 inches over Coastal Washington/Northern Oregon, and ~1 inch over far Northern California.

Click IVT or IWV image to see loop of ECMWF analyses/forecasts

Valid 0000 UTC 10 September – 0000 UTC 18 September 2020






Summary provided by C. Hecht, B. Kawzenuk, C. Castellano, J. Kalansky, and F. M. Ralph; 10 September 2020

*Outlook products are considered experimental