Large hard slab avalanches could be human triggered on steep avalanche prone slopes in areas with poor snowpack structure. Large triggers like snowmachines are more likely to trigger one of these dangerous slabs. Previous tracks may not be an indication of stability. Wind slabs could also be triggered by humans in very steep terrain at the higher elevations. A careful evaluation of the snow structure and conservative terrain choices are warranted in areas which exhibit poor snow structure. Avalanches are unlikely below an elevation of 7,500 feet except on isolated terrain features.
Areas of poor snowpack structure exist in the Togwotee Pass area, and the weight of a single person is still sufficient to trigger a deep persistent slab avalanche. Large triggers, such as snowmobiles, the release of a wind slab or a cornice failure, are more likely than an individual skier to trigger one of these deadly avalanches. Slab depths could vary from three to six feet.
At the higher elevations wind slabs formed by southwest winds could be triggered by skiers and riders in steep, wind loaded avalanche starting zones. These slabs could be 1 to 2 feet deep.
( Discussion is generated from the previous day's afternoon forecast. )Occasional light snowfall or flurries are possible overnight with less than an inch of accumulation. Snowfall is expected to develop from south to north in the morning, become heavy at times and end from south to north in the evening. Accumulations of 5 to 12 inches are possible in the mountains by early Saturday morning. Temperatures are forecast to drop into the teens and 20s tonight and rise into the 20s and 30s on Friday. Winds will be light from the west-southwest at 5 to 15 miles per hour.The general avalanche hazard is expected to be moderate. At the higher elevations skiers and riders could trigger soft slab avalanches one to two feet deep on very steep slopes. Tomorrow’s snowfall intensity and duration may vary significantly over very small distances. Some localized areas at the upper elevations could experience higher hazards associated with the new snowfall. In the Togwotee Pass and Greys River/Southwest Trails area large persistent deep slab avalanches continue to be a significant hazard. These dangerous slabs pose the greatest hazard to snowmobilers and could be 3 to 6 feet deep.
