Backcountry skiers and riders have the potential to trigger pockets of wind slab above 9000 feet. These slabs lie upon hard crusts formed during the Thanksgiving holiday rain event. If triggered, these slabs could bury someone in a terrain trap or carry someone through hazardous terrain given the early season conditions. At mid elevations avalanches are unlikely except for small isolated events and low elevations remain safe to avalanche hazard given low snow depths.
Soft or hard slabs with depths to two feet could be triggered in steep wind loaded terrain at the higher elevations. These slabs were formed by recent winds from the southwest that became stronger and have fluctuated from the northwest to the north for the last three days. These slabs will increase in sensitivity as the day warms.
Expect clear skies on Saturday as high pressure remains entrenched over the region. In the mountains, overnight lows will be in the low 20s before rising to near freezing during the heat of the day. Temperature inversions will again strengthen overnight will valley lows in the low single digits. Northerly to northwesterly ridgetop winds will decrease to 10 to 15 miles per hour.The general avalanche hazard is expected to be MODERATE above 9,000 feet on Saturday. Strong northwesterly ridgetop winds, particularly in the Tetons, have transported available snow and formed pockets of wind slab in leeward terrain near upper elevation ridgelines. These slabs rest above small grains of faceted snow and stout crusts from the end of November. Up there, skiers and riders could trigger these slabs in very steep, wind loaded terrain to depths of one to two feet. Evaluate the snowpack carefully, and don’t let the weekend and blue skies cloud your judgement. Conditions are likely to be different above 10,500 feet, and a heightened sense of awareness should be utilized. Shallow wet loose sluffs will also become possible on steep, sunlit aspects as the day warms. The chance for avalanche activity below 9,000 feet quickly diminishes as a mid-winter snowpack transitions to mostly bare ground at the valley floors.
