Residents along the Skagit River in Washington have been ordered to evacuate as the river is forecast to reach 13.55 m (44.47 feet) by late December 11, 2025. Heavy rainfall and rising rivers have led to emergency declarations across Washington State.
A major atmospheric river is producing very heavy precipitation across western Washington today into early December 11, 2025, triggering widespread and potentially historic riverine flooding, according to the Center for Western Weather and Water Extremes (CW3E). Forecasts indicate 130–200 mm (5–8 inches) of rain over the central and northern Washington Cascades and 75–130 mm (3–5 inches) over the Olympic Peninsula through 04:00 PST (12:00 UTC) on December 12. CW3E modeling shows 15 river gauges expected to exceed major flood stage and four to surpass record levels within 48 hours.
A strong atmospheric river brought significant flooding to parts of the Pacific Northwest through December 9, 2025, with rainfall rates in the Cascades exceeding 13 mm (0.5 inch) per hour and the Snoqualmie River cresting at 5.4 m (17.8 feet), its highest level in more than 10 years.
Subseasonal forecasts by CW3E show strong multi-model agreement on above-normal atmospheric river activity across the U.S. West Coast during mid- to late December, with the strongest signals over Northern California. Forecast regime tools indicate a transition from a West Coast Ridge to a Pacific Ridge during this period, altering temperature and precipitation patterns across the region.
Blizzard warning have been issued with snowfall totals of up to 30 cm (12 inches) being forecast across the high western slopes along with gusts of 80 km/h (50 mph) across multiple mountain counties. The warnings are in effect for parts of West Virginia, western Maryland, and western Virginia from 10:00 EST Wednesday, December 10, 2025 to 10:00 EST Thursday, December 11.
Two successive atmospheric river pulses are affecting the Pacific Northwest this week, delivering multi-day heavy rainfall and flooding risk across western Washington and northwestern Oregon. The first made landfall early December 9, and a stronger second pulse is forecast to arrive late December 9–early December 10, maintaining high integrated vapor transport and major flood potential through December 11.
Large portions of the northern United States are under winter storm warnings as a strong Alberta clipper advances into the Upper Midwest and separate winter storms persist across the northern Rockies from Tuesday morning through early Wednesday, December 9-10, 2025.
A strong Alberta clipper will bring heavy snow and gusty winds to the northern Plains and Upper Midwest from Tuesday, December 9, through early Wednesday, December 10, 2025, prompting winter storm watches across multiple states.
Flood watches and warnings were issued across western Oregon and Washington on December 7, 2025, valid through December 12, as strong atmospheric river produces sustained rainfall, rising river levels and increasing landslide risk.
A major atmospheric river (AR4–AR5 possible) is forecast to make landfall over the Pacific Northwest early Monday, December 8, 2025, and persist through Wednesday, December 10, bringing multiple days of heavy rain and elevated snow levels. Ensemble guidance shows ~70–80% of members reaching at least AR4 in southern coastal Washington, with ~20–30% indicating AR5, raising the risk of widespread riverine flooding.
