Western States Facing 'All-Day Onslaught' From Massive Winter Storm

(CNN)

A huge winter storm was affecting the West Coast on Sunday, poised to dump up to 10 feet of snow in some higher elevations, and causing flooding and potential mudslides in lower spots while impacting driving conditions and air travel, forecasters said.

A winter storm warning remained in effect through Monday afternoon for California's Sierra Nevada mountains, from Yosemite to Kings Canyon, according to the National Weather Service. "Storm totals of 5 to 10 feet above 7,000 feet are likely," the weather service said, and periods of heavy snow will continue through Monday. High winds are also forecast for the region.

"Travel into the high country of the southern Sierra Nevada may be difficult, if not impossible," according to forecasters.

That possibility exists for the northern Sierras as well. At 3:56 p.m. PST, the National Weather Service was predicting blizzard conditions with winds of up to 70 mph along the higher mountain passes. That could shut down traffic along Interstate 80, state Highway 50 and state Highway 88.

The Weather Service was urging residents in the higher mountain areas to check their generators and buy extra food and supplies.

"It's going to be an all-day onslaught," said CNN Meteorologist Reynolds Wolf. Areas from Denver westward will see rain, he said.

At lower elevations, heavy rain was causing flash flooding in a number of locations. Flood advisories and watches were posted almost the entire length of California, from Redding to San Diego. Los Angeles had received 2 to 3 inches of rain as of about 2:30 a.m. Sunday (5:30 a.m. ET), and "more significant rain" was on the way, forecasters said.