Dangerous avalanche conditions exist. Two avalanche problems confront backcountry users today. First, small to large wind slabs could be triggered by backcountry travels or release naturally. Second, large to very large deep persistent slabs could also be human triggered or release naturally. The deep persistent slabs are confined to terrain that held snow from early October, but pose a much greater threat with slab depths that could exceed five feet. Conservative decision making and expert route finding will be essential for safe travel in avalanche terrain.
Wind slabs up to three feet deep were formed by recent snowfall and very strong southwesterly to westerly ridgetop winds. In steep, wind-loaded avalanche terrain, these slabs could be triggered by backcountry travels or release naturally.
Deep hard slabs rest upon weak, faceted snow and crusts near the base of the snowpack. These instabilities exist on northwesterly to northeasterly aspects above 9,000 feet. Natural activity on this persistent weak layer occurred as recently as Friday in the Tetons. With slab depths in excess of five feet, surviving one of these slides is unlikely.
( Discussion is generated from the previous day's afternoon forecast. )Bitterly cold, arctic air will become entrenched overnight with mountain lows in the negative teens. During the day on Saturday, highs will be in the negative single digits at the higher elevations. Snowfall will cease, cloud cover will decrease, and ridgetop winds will veer to northwest and decrease to 5 to 15 miles per hour.The general avalanche hazard is expected to be CONSIDERABLE on Saturday. Two avalanche problems will confront backcountry travelers. First, wind slabs with depths up to three feet, which formed during the most recent storm cycle, could be triggered by backcountry travels or release naturally on a variety of aspects above 7,500 feet. Second, deep persistent slabs similar to Friday’s events could also be human triggered or release naturally. The deep persistent slabs are confined to terrain that held snow from early October, but pose a much greater threat with slab depths that could exceed six feet. Conservative decision making and expert route finding will be essential for safe travel in avalanche terrain.
