A powerful winter storm system is expected to hammer California later this week, bringing 5 to 10 feet of new snow between Thursday and Sunday to the Sierra Nevada, white-out conditions and the potential for extended highway closures.“If people are not already up here by Thursday morning, do not come,” said Andrew Schwartz, lead scientist at the UC Central Sierra Snow Lab at Donner Summit near Lake Tahoe. “It’s a shelter-in-place situation. People up here are buying fuel today for backup generators and boarding up their windows. It’s like watching people prepare for a hurricane.”

On Tuesday, the National Weather Service issued a blizzard warning — its first of the year — for the Northern and Central Sierra Nevada. The warning extends from 4 a.m. Thursday to 10 a.m. Sunday from Lassen and Shasta counties through Lake Tahoe to Tuolumne and Mono counties near Yosemite National Park.

Snow will begin falling Thursday, and become most extreme on Friday at amounts of 2 to 4 inches an hour, posing “near to impossible” conditions for drivers, winds up to 65 mph and power outages, the National Weather Service warned, with extended road closures possible on Interstate 80 and Highway 50, the main two routes that Bay Area residents use to go to Lake Tahoe area ski resorts.