Etna’s eruptive activity intensified rapidly between December 24 and 27, 2025, culminating in short-lived lava fountains about 200 m (650 feet) high and a new lava flow from the upper Voragine crater toward the Valle del Bove. INGV Etna Observatory (OE) raised the Aviation Color Code to Red on December 27 as tremor and infrasound amplitudes reached very high levels.
A major atmospheric river swept across Southern California from late December 24, 2025, into Christmas Day, December 25, triggering widespread flash floods, evacuations, debris flows, and power outages. Multiple counties including Los Angeles and Ventura were put under a State of Emergency. Rainfall totals reached 75–150 mm (3–6 inches) in coastal and valley areas, with up to 250 mm (10 inches) in higher terrain of Los Angeles and Ventura counties, prompting officials to urge residents to avoid travel.
The NWS Weather Prediction Center has issued a rare High Risk (level 4/4) for excessive rainfall across Southern California from Wednesday, December 24, through the morning of Thursday, December 25. 2025.
A strong atmospheric river is forecast to impact California from December 23 to 27, 2025, bringing widespread heavy rainfall, flash flooding, and high-elevation snow. The system is expected to produce 250 to 500 mm (10–20 inches) of precipitation in parts of the Sierra Nevada and 150 to 300 mm (6–12 inches) in the Coast and Transverse Ranges. The National Weather Service has issued high-risk alerts for flash flooding across southern California and moderate winter storm impacts over the Sierra Nevada.
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.
Three atmospheric rivers are expected to impact California between December 20 and 25, 2025, producing 250–500 mm (10–20 inches) of rain over the Sierra Nevada and 75–180 mm (3–7 inches) over southern coastal ranges. The strongest system is forecast to peak on December 23–25 with IVT values surpassing 750 kg m⁻¹ s⁻¹ and AR3–AR4 intensity.
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.
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 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.
A powerful winter storm hit the Pacific Northwest and parts of the inland Northwest on December 17, 2025, causing widespread power outages across Washington, Oregon, and Idaho. At least 596 830 electricity customers were left without power, an impact estimated to affect approximately 1.4–1.6 million people across the region, as strong winds damaged power infrastructure and disrupted services.
