CW3E Event Summary: 23-27 September 2020

September 29, 2020

Click here for a pdf of this information.

Active weather pattern brings first major precipitation event of the season to the Pacific Northwest

• A family of landfalling ARs produced heavy rainfall across western North America during 23–27 Sep
• Some locations along the northwestern coast of Oregon experienced AR5 conditions [based on the Ralph et al. (2019) AR scale]
• Total estimated 7-day precipitation ending 28 Sep exceeded 2 inches across most of western Washington and northwestern Oregon, with more than 5 inches (locally > 10 inches) in the Olympic Mountains and North Cascades

Click images to see loops of GFS IVT/IWV analyses Valid 0000 UTC 22 September – 0000 UTC 28 September 2020

Summary provided by C. Castellano, J. Kalansky, B. Kawzenuk, and F. M. Ralph; 29 September 2020