Oregon–Washington – Rain begins to intensify late tonight across the Blue Mountains, with steady downpours quickly overwhelming creeks and low-lying roads by early morning.
According to the National Weather Service in Pendleton, a Flood Watch is in effect from 11 p.m. tonight through Thursday evening for northeast Oregon and southeast Washington, including Pendleton, Walla Walla, and surrounding foothills. Rainfall totals will reach 3 to 4 inches in the mountains and 1.5 to 2.5 inches in foothill communities .
That much rain falling in a short window will lead to excessive runoff. Small creeks, streams, and drainage areas could rise quickly, especially near Meacham, Pilot Rock, Athena, and Dayton. Rural roads and low-water crossings may flood with little warning.
By early Wednesday morning, additional rainfall spreads north into southeast Washington and nearby Idaho, including Pullman, Moscow, and Colfax. These areas could see 0.5 to 1.5 inches of rain, adding to already saturated ground and increasing the chance of localized flooding.
Drivers along I-84, Highway 11, and US-12 should prepare for water pooling on roads and reduced visibility during heavier bursts. Avoid driving through flooded areas, even if water appears shallow.
Meteorologists note this system is part of a broader pattern bringing heavy mountain snow to the Rockies and severe storms to the Plains. Here, the focus remains on prolonged rainfall and runoff.
Rain continues through Thursday before gradually tapering late in the day. Flood warnings may be issued if water levels rise faster than expected.
