TRUCKEE, Calif. — A major highway was closed and ski resorts were shut down Sunday as the effects of a powerful blizzard continued to cause problems across the Sierra Nevada, and forecasters warned that more heavy snow was on the way for Northern California.

Sections of Interstate 80 to the west and north of Lake Tahoe were made impassable by blowing snow piling up in lanes, with no estimate for reopening, the California Highway Patrol said.

The CHP office in South Lake Tahoe warned motorists that tire chains for improved traction are required on routes through the mountains, where more than 7 feet of snow fell over the weekend. The online warning Sunday was accompanied by a photo of a big rig without chains stuck in whiteout conditions on a local road.

“Trying to bypass chain control, no no no!!” the agency said on X, formerly Twitter. “Dangerous and not smart.”

A blizzard warning was in effect until midnight for some areas above 6,500 feet, while lower elevations were under a winter storm warning with another 2 feet of snow possible, the National Weather Service office in Sacramento said. “Mountain travel is HIGHLY discouraged!” the office warned.

The multiday storm caused traffic backups and closures on I-80 and many other roadways, shut down ski resorts and left thousands of homes and businesses without power.

By Sunday evening, Pacific Gas & Electric had restored electricity to all but about 4,800 Northern California customers, while NV Energy had reduced its outages to roughly 1,000 homes and businesses across the state line in Nevada.

Palisades Tahoe, the largest resort on the north end of the lake and site of the 1960 Winter Olympics, was among several ski mountains that closed most or all chairlifts for a second straight day Sunday because of snow, wind and low visibility. Palisades reported a three-day snow total of 6 feet, with more falling.

“We will be digging out for the foreseeable future,” officials said on the resort’s blog.

Kevin Dupui, who lives in Truckee, just northwest of Lake Tahoe, said his snow blower broke, but it doesn’t really matter because there’s nowhere to put all the snow anyway. “We just move it around,” he said Sunday.