Heavy Rain in Polk County, Oregon

Station FW8313 in Salem.

An eastward-moving upper level trough and associated area of surface low pressure moved across northwest Oregon and southwest Washington September 17-18, resulting in fairly widespread showers and thunderstorms beginning late in the afternoon of the 17th through most of the day on the 18th. One severe thunderstorm developed southeast of Salem, OR during the overnight hours of Sept. 17-18, and moved northward across the eastern Willamette Valley and Cascade Foothills before eventually weakening over northeast sections of the Portland metro area. This storm produced hail to near 1 inch in diameter, wind damage, and locally heavy rain with minor street flooding. Other thunderstorms developed over southwest Washington during the afternoon and evening of the 18th, producing heavy rainfall and some local flooding.