A powerful series of winter storms is poised to unleash relentless rain, fierce winds, and heavy mountain snow across California this Christmas week, creating hazardous conditions for millions of holiday travellers.
Widespread Travel Chaos and Severe Warnings
The National Weather Service (NWS) has issued stern warnings as several atmospheric rivers are forecast to sweep through the state. Meteorologists predict Southern California could experience its wettest Christmas in years. "There's going to be a lot of water on the roadways, and it's going to be very dangerous travelling for the next couple of days," said NWS meteorologist Mike Wofford.
Scattered showers began on Tuesday morning, 23 December 2025, with the system expected to intensify through the afternoon and into Christmas Eve. While some areas may see a brief respite on Wednesday, another potent storm is waiting in the wings.
Immediate Dangers: Floods, Mudslides and White-Out Conditions
Much of the Sacramento Valley and the San Francisco Bay Area are under a flood watch and a high wind warning through Friday. In the Sierra Nevada, heavy snow and gusty winds starting Tuesday will create "near white-out conditions," making mountain passes "nearly impossible" to traverse. The northern coast also faces a risk of severe thunderstorms and a slight chance of tornadoes.
The threat is exacerbated in areas scarred by last January's deadly Palisades fire, where mudslides and debris flows are highly likely. Parts of Los Angeles are under evacuation warnings, with police officers door-knocking in vulnerable communities on the orders of Mayor Karen Bass's office.
Rainfall totals are forecast to be extreme. Southern California typically receives 0.5 to 1 inch (1.3-2.5cm) of rain in late December, but this week many areas could see 4 to 8 inches (10-20cm), with even higher amounts in the mountains.
Proactive Response and Previous Impacts
State and local officials are mobilising resources ahead of the emergency. Governor Gavin Newsom stated, "When severe weather threatens our communities, we don't wait to react. We get ahead of it." The state has pre-deployed first responders to coastal and Southern California counties, with the California National Guard on standby.
The severe weather has already taken a toll. Heavy rain and flash flooding that began last Saturday in Northern California have necessitated water rescues and resulted in at least one fatality, according to local officials.
This event follows a pattern of intense atmospheric river activity. Earlier in December, similar weather systems dumped nearly 5 trillion gallons (19 trillion litres) of rain on Washington state in one week, pushing rivers toward record flood levels.
