Seattle, WA – Washington is expected to see renewed flooding, heavy precipitation and high winds from December 20 into early January as a storm pattern fueled by atmospheric rivers sets up over the Pacific Northwest, according to the NOAA Climate Prediction Center.
Forecasters say a mid-level ridge over the Bering Sea and a downstream trough in the northeastern Pacific will direct multiple atmospheric river events into the region beginning around December 20. With soils already saturated from earlier flooding across western Washington and northwestern Oregon, officials warn that the risk of additional flooding will “remain elevated” into late December at minimum.
According to NOAA, a moderate risk (40–60%) of heavy precipitation is posted from most of western Washington southward into west-central California from December 20–26. High winds are also likely as enhanced onshore flow develops, with the strongest gusts expected along the coast and at higher elevations.
Mountain areas, including the Cascades, are forecast to receive heavy snow, which may compound travel hazards and increase avalanche concerns. Landslide vulnerability will remain high across saturated terrain, especially in western Washington counties that experienced flash flooding earlier this month.
During this period, the pattern favors repeated moisture surges into the Pacific Northwest, with above-normal precipitation likely to extend south into Oregon and portions of California. NOAA notes that the La Niña pattern, combined with enhanced onshore flow, is expected to persist into the New Year.
Residents are encouraged to monitor local National Weather Service offices for updated flood watches, wind advisories and winter storm alerts as the event approaches.
