CW3E Event Summary: 4-8 February 2020

February 11, 2020

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Landfalling AR brings heavy rainfall, mountain snowfall, and flooding to the Western U.S

  • A long-duration, inland-penetrating AR impacted the Pacific Northwest and Rocky Mountains during 4–8 Feb
  • Some locations in coastal Washington experienced AR conditions for more than 72 hours
  • Total estimated 7-day precipitation between 3 Feb and 10 Feb exceeded 10 inches over the WA Cascades
  • At least 1–3 feet of snow fell over the elevated terrain in the interior Pacific Northwest and the Rocky Mountains
  • Heavy rainfall on top of saturated soils resulted in river flooding and landslides in western WA

Click IVT or IWV image to see loop of GFS analyses

Valid 0000 UTC 4 February – 1800 UTC 8 February 2020








Summary provided by C. Castellano and F. M. Ralph; 11 February 2020