Atmospheric River Setting Up Fresh Flooding Risk For Pacific Northwest, Which Has Already Been Blasted By Heavy Rain

A storm system combined with an atmospheric river is set to sweep across the Pacific Northwest, delivering additional heavy rainfall Monday to a region that has already endured weeks of relentless wet weather.

The atmospheric river is expected to influence the area from now into Tuesday. Broad areas could see rainfall totals of 1-2 inches, while higher amounts — ranging from 3-5 inches — are possible in spots like the Olympic Mountains and the foothills of the Cascades, according to the National Weather Service (NWS). (RELATED: Eastern United States Being Threatened By Snow From Complex Winter Storm)

An atmospheric river forms as a narrow band of concentrated moisture, often originating from tropical regions, that gets transported along the jet stream. These phenomena are described as the largest “rivers” on Earth, though they flow through the atmosphere rather than across land.

After months of persistent rain, Washington state is overdue for a break from precipitation. Seattle currently stands about half an inch above its normal year-to-date rainfall accumulation, and many rivers throughout the region are running close to or at flood levels.

Western Washington will see another round of heavy rain as an atmospheric river hits the region from late Saturday until Monday, forecasters said. https://t.co/hTbv4ZgLgf

— The Seattle Times (@seattletimes) January 11, 2026

Tragically, in recent weeks, one fatality occurred due to severe flooding in Northern California.

Two levee breaches in Washington caused extensive inundation, flooding entire neighborhoods and impacting more than 220 houses in the city of Pacific. Additionally, a man lost his life after driving into floodwaters on a submerged road slightly south of Snohomish.

With a surge of warmer air moving through the region, snow levels are projected to rise sharply — from around 2,500 feet to above 7,000 feet by Sunday evening — posing significant risks for travel over mountain passes.

Rivers including the Skykomish, Snohomish and Skagit are already approaching bankfull, raising concerns that the incoming rain could spark renewed flooding in the early part of this week.