WASHINGTON – A powerful storm system paired with an atmospheric river is set to move through the Pacific Northwest on Monday, bringing another round of heavy rain to a region already saturated by weeks of persistent precipitation. Forecasters warn that rising rivers, elevated snow levels, and ongoing runoff could increase flooding risks across Washington through early next week.
Atmospheric River to Deliver Inches of Rain
An atmospheric river is expected to impact the region from Monday through Tuesday, producing widespread rainfall totals of 1 to 2 inches, with localized amounts of 3 to 5 inches possible in the Olympic Mountains and Cascade foothills.
Atmospheric rivers are long, narrow bands of concentrated water vapor—often originating in the tropics—that travel along the jet stream. Though invisible, they can transport immense amounts of moisture and are often responsible for the most intense rainfall events along the West Coast.
Washington Already Near Flood Thresholds
After months of steady precipitation, much of Washington is already vulnerable. Seattle is currently about half an inch above its year-to-date rainfall average, and many rivers across the state are running high.
The Skykomish, Snohomish, and Skagit rivers are already near bankfull levels, meaning additional rainfall could quickly push them into flood stage by early next week.
Recent Flooding Has Turned Deadly
Flooding across the West has already had deadly consequences in recent weeks. In Northern California, one person died amid dangerous flood conditions tied to earlier storms.
In Washington, two levees failed, triggering widespread flooding in the city of Pacific, where more than 220 homes were affected. In another incident, a man drowned after driving his vehicle onto a flooded roadway just south of Snohomish.
Emergency officials continue to urge residents to avoid flooded roads, as water depth and current strength are often difficult to judge.
Rising Snow Levels Add to Hazards
As warmer air moves into the Pacific Northwest, snow levels are forecast to rise sharply—from around 2,500 feet to above 7,000 feet by Sunday evening. This shift increases the risk of rapid snowmelt, adding more runoff to already swollen rivers and creating hazardous travel conditions through mountain passes.
According to the FOX Forecast Center, the combination of heavy rain and elevated snow levels could significantly worsen flooding concerns, especially in low-lying and river-adjacent communities.
What Comes Next
Forecasters say the greatest flooding risk may develop by early next week as runoff accumulates. Residents in flood-prone areas are advised to closely monitor river forecasts, remain alert for evacuation notices, and avoid unnecessary travel during periods of heavy rain.
Officials stress that even moderate additional rainfall could have outsized impacts due to already saturated ground conditions across much of western Washington.
