A major snowstorm bore down Friday on the Sierra Nevada, including the Lake Tahoe area, with as much as 10 feet of snow expected at higher elevations. Forecasters issued dire warnings about trying to drive through blustering winds and whiteout conditions, and Yosemite National Park was closed.

“Your safe travel window is over in the Sierra,” the National Weather Service in Reno, Nev., posted on social media. “Best to hunker down where you are.”

The National Park Service said that visitors who were already in Yosemite on Friday morning must leave by noon. Many ski resorts in the region announced that they were closing for the day.

One resort, Palisades Tahoe, posted on social media that it had seen “intense” snowfall and winds of 100 miles an hour. In videos posted by the resort, ski lifts were faintly visible through a blanket of white, and the sky and the ground were indistinguishable from each other.

The resort, which was packed last weekend for a major ski competition, had become “an absolute ghost town” by Friday, said Veronica Berkholtz, a manager of the coffee shop at Palisades Tahoe.

Meteorologists began sounding rare alarms earlier this week about “life-threatening blizzard conditions” expected in the mountains of the Sierra Nevada, saying the approaching storm could drop more than three feet of snow through Sunday.