The National Weather Service has issued a Winter Storm Warning effective through 6 AM on Sunday. At the mid and upper elevations, skiers and riders could trigger loose snow sluffs and pockets of newly developed wind slab in steep, avalanche-prone terrain. As the day progresses, the hazard will increase as these slabs gain depth and volume. Monitor snowfall amounts and avoid steep terrain with obvious signs of wind loading. The lower elevation snowpack, which has undergone numerous melt-freeze cycles and rain events, is mostly resistant to wet slides even with valley rain in the forecast.
New wind slabs, which are forming upon a warm snowpack, will continue to build as the day progresses. Backcountry travelers venturing into steep, wind-loaded avalanche terrain could trigger these slabs to depths of 6 to 18 inches by this evening. This hazard is likely to be elevated above 10,500 feet.
Periods of moderate to heavy snowfall are expected overnight as a moist air mass and cold front bring snow showers to the region. Scattered snow showers will continue during the day on Sunday. Overnight lows in the mountains will drop into the mid to upper teens before rising into the low to mid 20s on Sunday. By the early morning hours, the valleys will fall into the low 20s followed by afternoon highs in the mid to upper 30s. Westerly ridgetop winds will pick up to 25 to 35 miles per hour overnight and continue through the day on Sunday.The general avalanche hazard is expected to be MODERATE on Sunday. Cold nighttime temperatures should decrease the chance of avalanches involving the recent snowfall. Overnight, strong westerly ridgetop winds and moderate to heavy snowfall will combine to create new wind slabs in leeward terrain at the higher elevations. Skiers and riders could trigger these slabs to depths of a foot in steep, wind-loaded terrain. The threat of wet slides involving the new and recent snowfall could return in the afternoon on sunlit aspects if extended periods of sunshine occur. Avalanche activity below Friday’s old snow surfaces is unlikely.
