A blizzard has raged overnight in the Sierra Nevada mountains as the biggest storm of the season shut down a long stretch of the Interstate-80 road in California, while high winds and heavy rain left tens of thousands of people without power.

Up to 10ft of snow is expected in some areas.

The US National Weather Service in Reno said it expects the heaviest snow to arrive early on Saturday, continuing with blizzard conditions that could reduce visibility to a quarter mile or less.

A car drives in heavy snow
Residents have been urged to take shelter and stay off roads (Bay Area News Group via AP)

“High to extreme avalanche danger” is expected in the backcountry through until Sunday evening throughout the central Sierra, including the greater Lake Tahoe area, the weather service said.

On Friday, California authorities shut down 100 miles of I-80 due to “spin outs, high winds, and low visibility”.

They had no estimate when the main road would reopen from the California-Nevada border just west of Reno to near Emigrant Gap, California.

Pacific Gas and Electric reported at around 10pm on Friday (6am on Saturday GMT) that 24,000 households and businesses were without power.

Someone shovels snow
As much as 10ft of snow is expected in some areas (Bay Area News Group via AP)

A tornado touched down on Friday afternoon in Madera County and caused some damage to an elementary school, said Andy Bollenbacher, a meteorologist with the National Weather Service Hanford.

Some of the ski resorts that shut down on Friday said they planned to remain closed on Saturday to dig out with a view to reopening on Sunday.

Palisades Tahoe, the largest resort on the north end of Tahoe and site of the 1960 Winter Olympics, said it hoped to reopen some of the Palisades slopes at the lowest elevation on Saturday but would close all chairlifts for the second day at neighbouring Alpine Meadows due to forecasts of “heavy snow and winds over 100mph”.

Snowy road
The warning lasts through until Sunday (AP)

Palisades Tahoe said Friday on X: “We have had essential personnel on-hill all day, performing control work, maintaining access roads, and digging out chairlifts, but based on current conditions, if we are able to open at all, there will be significant delays.”

The storm began barrelling into the region on Thursday. A blizzard warning lasting until Sunday morning covers a 300-mile stretch of the mountains.

Meteorologists predict as much as 10ft of snow is possible in the mountains around Lake Tahoe by the weekend, with 3-6ft in the communities on the lake’s shores and more than a foot possible in the valleys on the Sierra’s eastern front, including Reno.

Yosemite National Park closed Friday and officials said it would remain closed through at least noon on Sunday.