Two avalanche problems will confront backcountry users today. Above 7,500 feet, skiers and riders could trigger small to large wind slabs in steep, wind-loaded avalanche terrain. In terrain above 9,000 feet that held snow from early October, very large persistent deep slabs could be human triggered. Evaluate the snowpack and terrain carefully. The snowpack is mostly stable below 7,500, and avalanches are unlikely.
South-southwesterly to west-northwesterly ridgetop winds have combined with recent snowfall to form wind slabs in leeward terrain above 7,500 feet. Skiers and riders could trigger these slides to depths of three feet on steep, wind-loaded slopes.
On northwesterly to northeasterly aspects above 9,000 feet, backcountry travelers could trigger persistent deep slab avalanches failing on weak, faceted snow near the base of the snowpack. Large triggers, such as snowmobiles, are more likely to cause failure of this basal weak layer. Previous tracks are not an indication of stability with a persistent deep slab problem. These dangerous and destructive slides could reach six feet in depth and are likely unsurvivable.
( Discussion is generated from the previous day's afternoon forecast. )The stream of Pacific moisture will bring a few inches of new snow overnight before tapering off by morning. Cloud cover will then decrease during the day. Overnight lows in the mountains will drop into the single digits before rising into the mid teens in the afternoon. Westerly to northwesterly ridgetop winds will range from 15 to 25 miles per hour.The general avalanche hazard is expected to be MODERATE in the Tetons and Greys River forecast zones on Saturday. There, backcountry travelers might still be able to trigger a deep persistent slab in terrain that held snow from early October. Large triggers, such as snowmobiles, are more likely impact this basal weak layer. Skiers and riders could also trigger wind slabs to depths of three feet in steep, wind-loaded avalanche terrain above 7,500 feet.In the Togwotee Pass area, where the snow depths are shallower, the general avalanche hazard is expected to remain CONSIDERABLE due to the increased likelihood of triggering a deep persistent slab. Wind slabs, similar to those in the other forecast zones, will also be a problem of concern.
