Seattle, Washington – A more active winter pattern is expected to take shape along the Pacific Coast as the New Year approaches, with growing signals for mountain snow, valley rain, and periods of travel disruption from Dec 27 through Jan 9.
Atmospheric patterns favor repeated Pacific systems moving inland during this window, increasing confidence in snow across higher elevations of Washington, Oregon, Idaho, and Northern California. According to the National Weather Service, colder air filtering in behind these systems may allow snow levels to drop at times, especially late at night and during early morning hours. The Cascades, Siskiyous, and northern Sierra are currently favored for significant snowfall, with impacts possible at mountain passes.
Major routes including Snoqualmie Pass on I-90, Stevens Pass on US-2, Santiam Pass on US-20, and Donner Pass on I-80 could experience periodic closures or chain requirements during heavier snow periods. Idaho’s higher terrain may also see accumulating snow affecting US-95 and I-84 near the Blue Mountains.
Lower elevations, including coastal cities and interior valleys, are more likely to see rain, though brief rain-snow mixes cannot be ruled out if colder air pushes farther west. Gusty winds with stronger systems may bring isolated power outages, particularly along the Washington and Oregon coasts.
State transportation agencies urge travelers to monitor pass conditions, carry chains when required, and allow extra time during peak holiday travel. Residents should secure outdoor items, prepare for power interruptions, and remain weather-aware. While breaks between storms are expected, the overall pattern supports a stormy and wintry start to 2026 across the Pacific Coast and inland Northwest.
