California Faces Dangerous Atmospheric River From Weekend Into Christmas Week, With Up to 8 Feet of Snow in the Sierra and 20 Inches of Rain in Flood-Prone Foothills
CALIFORNIA — A prolonged and intense atmospheric river is set to hit California beginning late this weekend and continuing into Christmas week, prompting Winter Storm Watches and Flood Watches across large sections of the state. Meteorologists warn that this system could deliver up to 8 feet of snow in the Sierra Nevada and as much as 20 inches of rain on west-facing foothills, creating a dangerous combination of flooding, landslides, whiteout conditions, and travel shutdowns.
State officials are preparing for what could be one of the most impactful moisture events of the season, with additional watches and warnings expected as the system approaches.
Major Snowfall Threat for the Sierra Nevada
Winter Storm Watches now cover much of the northern, central, and southern Sierra, with snowfall projections including:
- 6–8 feet of snow in the central Sierra
- 3–5 feet for the southern Sierra
- 4 feet or more on the highest peaks
- Snow levels dropping to 5,500 feet, affecting major travel corridors such as I-80 and Highway 50
Travel through the Sierra is expected to become extremely hazardous or impossible as heavy snow, strong winds, and whiteout conditions develop.
Flood Watches Issued for Foothills and Northern California
Flood Watches are in effect across parts of northern and central California, where rainfall totals could reach:
- 3–9 inches across broad foothill regions
- Up to 20 inches on west-facing slopes exposed to strong atmospheric river flow
The combination of saturated ground, steep terrain, and heavy rainfall increases the risk of:
- Flash flooding
- Debris flows and landslides
- Rapid river rises
- Road closures and travel disruptions
Officials warn that low-lying neighborhoods and communities near burn scars face heightened danger.
Southern California Alerts Expected Soon
Forecasters note that additional alerts are likely for Southern California, including flood advisories and potential winter weather hazards for mountain communities. Los Angeles and surrounding regions may see heavy rainfall as the storm’s southern edge intensifies.
Impact on National Weather Patterns
Atmospheric rivers often influence downstream storm development, which could help shape late-December weather systems that eventually reach the Midwest — including Illinois. For continued national storm tracking and Midwest impact updates, follow NapervilleLocal.com.
I’ve lived in Naperville long enough to see how quickly our community changes — from new developments downtown to sudden shifts in our Midwest weather. Reporting on Naperville news and daily forecasts gives me the chance to keep neighbors informed about what really matters. My goal is simple: deliver clear, timely updates so you always know what’s happening in our city and what to expect from the skies above.