Northern California is bracing for the first major storm of 2026 as a cold, moisture-laden atmospheric river is set to arrive Friday evening, bringing widespread rain, strong winds, and significant mountain snowfall through early next week.
Forecasters say the storm will intensify overnight Friday, with impacts peaking over the weekend and lingering into Tuesday. Flooding concerns are rising in valley and foothill communities, while dangerous winter conditions are expected across the Sierra Nevada.
Storm Timeline and What to Expect
The system is expected to move into the region Friday evening, initially producing scattered light showers. Conditions will deteriorate quickly overnight as stronger bands of rain move inland.
By Saturday morning, sustained winds of 20–30 mph are expected from Sacramento east toward South Lake Tahoe, with gusts increasing through the afternoon. Thunderstorms are also possible Saturday, adding to the risk of localized downpours.
Although there may be brief lulls in precipitation, forecasters warn that periods of rain and snow will continue through at least Tuesday, making this a long-duration event rather than a quick-moving storm.
Rainfall Forecast Across Northern California
Low-elevation areas are expected to see steady rainfall, with totals varying widely by location.
Communities including Vacaville, Sacramento, and Marysville could receive up to 2 inches of rain by Sunday. Grass Valley may see as much as 4 inches, while Placerville could receive around 3 inches over the course of the storm.
In the San Joaquin Valley, cities such as Stockton and Modesto are forecast to pick up as much as 1 inch of rain. While totals there are lower, saturated ground could still lead to localized flooding.
The National Weather Service has issued a flood watch for areas below 4,000 feet in the Sacramento Valley and nearby foothills. The watch begins at 10 p.m. Friday and remains in effect until 4 p.m. Monday. Officials warn that urban flooding and small-stream overflow are possible during periods of heavy rainfall.
Heavy Snow and Whiteout Conditions in the Sierra
Above 5,500 feet, the storm is expected to deliver major snowfall. Forecasters estimate 2 to 4 feet of snow could accumulate in the Sierra through Sunday, with additional snowfall possible into Monday.
Snow levels may dip to around 4,500 feet at times, though the most intense accumulation will remain at higher elevations. A winter storm warning is in effect from 10 p.m. Friday through 4 p.m. Monday, as moderate to heavy snow could create whiteout conditions and severely reduce visibility.
Mountain travel is strongly discouraged during peak storm periods. Chain controls are expected over Sierra passes, and drivers are urged to check conditions through Caltrans before heading out.
Strong Valley Winds Add to Hazards
In addition to rain and snow, gusty winds will impact much of the Sacramento Valley and surrounding foothills. A wind advisory is in effect from late Friday through Sunday.
South winds are expected to range from 15 to 25 mph, with gusts reaching up to 45 mph in some areas. The strongest winds are forecast north of Sacramento, particularly around Chico, where downed tree limbs and isolated power outages are possible.
Safety Reminders for the Weekend
Residents are advised to avoid unnecessary travel during periods of heavy rain or snow, secure loose outdoor items ahead of strong winds, and remain alert for flooding in low-lying or poor-drainage areas. Mountain travelers should carry chains, emergency supplies, and be prepared for rapidly changing conditions.
With impacts spanning valleys to high elevations, officials say preparation and caution will be key as Northern California faces its first major winter storm of the new year.
