Two atmospheric rivers are forecast to hit the Pacific Northwest and northern California, starting late Thursday, October 23, 2025. The systems are forecast to bring in heavy rainfall of over 130 mm (5 inches) along with mountain snow across Washington, Oregon, and northern California.
Tornado warnings were issued across parts of Central California, including San Luis Obispo County, as a rare October storm brought heavy rainfall, gusts exceeding 110 km/h (70 mph), and localized flooding on October 13–14, 2025. Evacuation warnings were declared in Los Angeles County for burn-scar areas at risk of debris flows, while forecasters maintained a marginal tornado risk for southern coastal regions.
A Pacific storm will move into California from the northwest between October 13 and 15, 2025, bringing widespread valley rain and heavy snow to the Sierra Nevada. Snowfall totals along the Sierra crest may reach 30–90 cm (12–36 inches), with hazardous driving conditions expected across Interstate 80 and other major passes. The National Weather Service warns that chain controls and travel delays are likely during the peak of the event.
A predecessor rain event (PRE) associated with Hurricane Priscilla is forecast to produce sustained rainfall across the Southwestern United States, particularly Arizona and New Mexico, between October 9 and 11, 2025.
A section of coastal bluff measuring about 91–122 m (300–400 feet) collapsed in Rancho Palos Verdes, California, on September 28, 2025, falling 15–18 m (50–60 feet) toward the ocean. Four backyards were damaged, but no homes sustained structural damage, and no injuries were reported. Authorities said the collapse occurred outside the long-active Portuguese Bend Landslide Complex, located about 6 km (4 miles) away.
A series of atmospheric rivers (AR) is forecast to hit the U.S. West Coast from late September through early October, beginning with a strong AR that made landfall over British Columbia on September 26, 2025. Forecasts show moderate AR conditions in Washington, Oregon, and northern California on September 28, followed by a stronger system making landfall on September 30 and potentially continuing into October 7.
Flooding triggered by the remnants of Tropical Storm Mario caused the death of a 2-year-old in the city of Barstow, California, after he got swept away by the floodwaters on September 18, 2025. The fatality was confirmed by the police on September 19, after the body of the deceased was found in a flood control channel in the area.
Remnants of Tropical Storm Mario brought widespread rainfall to California and the Desert Southwest on September 17–18, 2025, prompting water rescues, triggering mudslides, and flash flooding across the region.
Moisture from post-tropical Mario is forecast to spread into southern California on September 18, 2025, bringing thunderstorms and rainfall totals of 25–75 mm (1–3 inches) through Friday. Rainfall rates may exceed 25 mm/h (1 inch/h), prompting Flood Watches and Flash Flood Watches across much of the region. Arizona and New Mexico are also expected to see widespread showers and thunderstorms with localized flooding into September 19.
A lightning-sparked wildfire known as Garnet Fire entered the McKinley Grove of giant ancient sequoias in California’s Sierra National Forest on September 8, 2025. Firefighters reported ember ignition in upper branches but no complete canopy burn. Containment stands at about 15% after burning 22 000 ha (55 000 acres) since igniting on August 24.
