One person was killed and several were rescued after torrential rain from an atmospheric river caused severe flooding in Redding, northern California, on December 21–22, 2025. Rainfall totals above 100 mm (4 inches) overwhelmed storm drains, flooded roads.
Forecast models indicate that the Polar Vortex will strengthen in late December 2025 after a split and disrupted phase earlier in the season. The recovery is expected to influence North American and European weather in January 2026, potentially sending colder air southward while reorganizing jet stream flow.
A series of impactful atmospheric rivers is forecast to bring heavy precipitation across California from Friday, December 19, 2025, through Wednesday, December 24, with seven-day precipitation totals expected to exceed 380 mm (15 inches) in parts of the Sierra Nevada.
The National Weather Service (NWS) office in Boulder issued a Particularly Dangerous Situation (PDC) for rapid wildfire spread affecting the foothills and along Colorado Highway 93 through Friday, December 19, 2025.
A powerful windstorm with gusts reaching 232 km/h (144 mph) battered parts of the Pacific Northwest and Rockies this week, leaving one dead, two injured, and hundreds of thousands without power by December 18, 2025. The deep low-pressure system continues moving east toward the northern Plains and Midwest, sustaining severe winds and wildfire risks.
A strong M7.0 oblique-slip earthquake struck beneath the Hubbard Glacier in the St. Elias Mountains, about 89 km (55 miles) north of Yakutat, Alaska, at 11:40 AKST (20:40 UTC) on December 6, 2025. The quake triggered widespread ground failures, with over 700 landslides and snow avalanches identified across Alaska and Canada. The largest and most concentrated slope failures occurred within a 16 km (10 miles) wide band along the estimated fault rupture.
Blizzard Warnings are in effect across parts of Montana, North Dakota, and Minnesota through Thursday, December 18, 2025, due to a fast-moving winter storm producing widespread blizzard conditions and destructive winds across the region.
A fast-moving winter storm is forecast to bring widespread blizzard conditions and destructive winds across parts of Montana, North Dakota, and Minnesota through Wednesday night into Thursday, December 17 into 18, 2025. The system, driven a deep low-pressure trough, is generating gusts up to 110 km/h (70 mph) and localized peaks over 130 km/h (80 mph) in leeward mountain areas, potentially leading to whiteout conditions, road closures, and power outages across the region.
The Center for Western Weather and Water Extremes (CW3E) at UC San Diego forecasts above-normal precipitation for Northern and Central California between late December 2025 and early January 2026. The latest subseasonal outlook, issued on December 16, indicates high confidence in enhanced atmospheric river (AR) activity and persistent Pacific Ridge conditions during the period from December 22 to January 11, 2026.
Forecast models suggest that El Niño conditions are likely to develop during 2026, marking a shift from the ongoing weak La Niña. The transition is expected to influence jet stream patterns and temperature anomalies across the United States, Canada, and Europe, potentially reshaping rainfall distribution and winter storm activity in the Northern Hemisphere.
