A strong atmospheric river slammed into the Pacific Northwest and British Columbia, delivering heavy rainfall and strong winds to the region.

Beginning on December 8, 2025, a plume of moisture originating from the tropics arrived in the Pacific Northwest, leading to multiple inches of rainfall accumulating in just a couple of days. This compounded into a widespread flooding threat, particularly for western Washington, as well as a river flooding threat due to the rising water levels. Several days into the atmospheric river event, mudslides and landslides became a concern on the Olympic and Cascade mountain ranges.

Evacuations were issued in Washington state, as well as a state of emergency declared by the governor due to the catastrophic and potentially historic flooding. Multiple rivers in western Washington are forecast to reach the major flooding stage, with some even setting new records.

Washington was not the only state that was impacted by the atmospheric river, but other nearby states like Oregon, Idaho and Montana were also soaked in the heavy rainfall.

For more information, visit the Weather Prediction Center. For information on the river flood stages, visit the Water Prediction Service. For rain totals, visit the CoCoRaHS website.