A winter storm pounded the western U.S. on Saturday, dumping heavy rain and snow in the Sierra Nevada that shut down mountain highways and triggered flood watches and avalanche warnings.
From the coast of Northern California to Lake Tahoe, the storm also packed powerful winds that toppled trees. It was expected to bring as much as 4 feet of snow by the end of the weekend around Lake Tahoe’s upper elevations and as much as 6 feet in remote parts of the Sierra to the north and south.
On Saturday night, the UC Berkeley Central Sierra Snow Lab tweeted that they were seeing 4 to 5 inches of snow per hour, what it said was the heaviest of the day.
A winter storm warning remained in effect for more than 250 miles of the Sierra at least until Sunday night or early Monday from north of Reno to south of Yosemite National Park.
The National Weather Service warned the system could develop into a possible blizzard across the Northern Plains this week.
A 70-mile stretch of eastbound U.S. Interstate 80 was closed "due to zero visibility" from Colfax, California, to the Nevada state line, transportation officials said. Chains were required on much of the rest of I-80 in the mountains from Reno toward Sacramento.
A stretch of California Highway 89 also was closed due to heavy snow between Tahoe City and South Lake Tahoe, California, the highway patrol said.
The U.S. Forest Service issued an avalanche warning for the backcountry in the mountains west of Lake Tahoe, where it said "several feet of new snow and strong winds will result in dangerous avalanche conditions."
Gusts of wind up to 50 mph that sent trees into homes in Sonoma County on Saturday could reach 100 mph over Sierra ridgetops by early Sunday, the National Weather Service said.
Heavy rain was forecast through the weekend from San Francisco to the Sierra crest, with up to 2 inches in the Bay Area and up to 5 inches at Grass Valley northeast of Sacramento.
The Associated Press contributed to this report.