SAN FRANCISCO (CBS SF) – The first of two potent winter storm fronts buried the Sierra under several feet of snow Wednesday with a second more powerful weather system expected to roar into the region over the weekend.

The National Weather Service issued several warnings for the mountain range including a winter storm warning for the Lake Tahoe area while the Sierra Avalanche Center issued its highest level of avalanche warning for the region.

The Nevada Department of Transportation was forced to shut down the Mt. Ski Bowl Highway as it leads to the Mt. Rose ski resort due to an avalanche.

State transportation officials said no one was hurt in the small avalanche. Nevada Department of Transportation spokeswoman Meg Ragonese said crews trying to reopen Mount Rose Highway are dealing with near white-out conditions.

Blizzard conditions have also forced the closure of Nevada Highway 431, the main highway connecting Reno to Lake Tahoe

The National Weather Service in Sacramento reported that as of 8 a.m. Wednesday, the storm system has dumped 56 inches of new snow at Boreal, 53 inches at Squaw and 46 inches at Sierra-at-Tahoe.

Officials at Mammoth Mountain in the Southern Sierra reported they have received as much as 50 inches of snow by Wednesday afternoon. Cars were buried in the resort’s parking lot and crews were busy clearing mounds of snow.

While the first storm front delivered a wintry punch, forecasters warned the weekend storm could be even more powerful.

Forecasters said the storm would tamper off on Thursday with a brief break Friday before another strong atmospheric river off the Pacific brings copious amounts of rain and snow to the region Saturday through Monday.

Snowfall of up to 6 feet were predicted for the higher elevations while flooding would be an increasing concern for rivers, creeks, and streams this weekend into early next week at lower elevations.

Snow levels would climb to 7000-8000 feet Saturday night when the heaviest precipitation arrives and peak Sunday-Sunday night when snow levels could reach 9000-9500 feet.