RENO, Nev. (AP) -- Another winter storm packing heavy snow and powerful winds was moving into the northern Sierra Nevada late Friday where as much as 4 feet (1.2 meters) of snow is forecast in the upper elevations around Lake Tahoe over the weekend.
The National Weather Service issued a winter storm warning for a 250-mile (400-kilometer) stretch of the Sierra beginning late Friday north of Reno along the California-Nevada line. It goes into effect at 4 a.m. Saturday around Lake Tahoe and as far south as Mammoth Lakes, California. The storm warning doesn't expire in most areas until Monday.
The U.S. Forest Service activated a backcountry avalanche watch late Friday in the central Sierra including Tahoe and warned of higher avalanche danger Saturday into Sunday.
"A winter storm with gale force winds, high intensity snowfall and feet of new snow accumulation may result in widespread avalanche activity in the mountains," the Forest Service Sierra Avalanche Center said Friday.
As much as 18 to 28 inches (45 to 71 centimeters) of snow is forecast through the weekend at lake level, and up to 4 feet (1.2 meters) at elevations above 7,000 feet (2,133 meters) with 50 mph (80 kph) winds and gusts up to 100 mph (160 kph).
Authorities urged motorists to stay off mountain roads in the Sierra through the weekend.
"You could be stuck in your vehicle for many hours," the weather service in Reno warned.
On the Sierra's eastern slope, a winter weather advisory runs from 10 p.m. Saturday to 10 a.m. for Reno, Sparks and Carson City, with snow accumulations of 1 to 3 inches (2.5-7.5 cm) on valley floors and up to 8 inches (20 cm) above 5,000 feet (1,524 meters).