WASHINGTON & OREGON — Another strong wave of Pacific moisture is set to move into the Pacific Northwest tonight and continue through Thursday, bringing heavy rainfall, already-saturated soils, and a significantly elevated threat of landslides across large portions of Western Washington and western Oregon. Officials and forecasters are urging residents to remain alert as the region faces yet another dangerous round of weather impacts.
Heaviest Rainfall Expected From SW Washington Into Western Oregon
According to the latest projections, the heaviest rain will target southwestern Washington and western Oregon, where moisture is expected to funnel inland throughout the night. Many communities in these regions have already endured days of continuous rainfall, which has weakened soil structure and increased the potential for slope failures.
The rainfall tonight will contribute to an escalating situation, with forecasters noting that even moderate precipitation falling on top of unstable ground can trigger landslides, debris flows, and rapid slope movement. Areas near major foothills, river valleys, and steep terrain—including Port Angeles, Olympia, Tacoma, Everett, and Seattle—remain especially vulnerable.
Why the Risk Has Escalated: Saturated Soils and Continuous Storms
What makes this incoming moisture event particularly dangerous is the extreme level of soil saturation across much of Western Washington. Over the past week, the region has experienced multiple atmospheric disturbances, each delivering heavy rain. As a result, drainage systems, hillsides, and slopes are at or near full capacity.
This new wave of moisture will add pressure to an already fragile landscape. Forecasters warn that landslides often occur after prolonged rainfall rather than during isolated storm bursts, meaning the combination of recent storms and tonight’s incoming precipitation significantly raises the threat level…