Conditions are dangerous and are likely to be that way for a while. Steep slopes are unstable and have produced large slab avalanches. A snowboarder died yesterday on Togwotee Pass after he was fully buried at the base of a steep creek bank. A snowmobiler died in the Salt River Range on Wednesday after his group was caught in an avalanche and he was fully buried. The Greys River area has received three to six feet of new snow in the past 3 weeks. This snow lies upon persistent weak layers of faceted snow. Large slab avalanches involving all this new snow can be easily triggered by snowmachines and skiers on steep slopes. Natural avalanche activity is possible. At least 12 people have been caught in avalanches in Western Wyoming since Sunday. Twenty-two people have died in avalanches in the United States since January 30. Expert terrain and route selection skills are essential for safe travel in avalanche terrain.
Large to very slab avalanches could be easily triggered by a person or by a smaller wind slab avalanche on a variety of aspects. These slabs could be three to six feet deep.
In steep, wind-loaded terrain above 8,000 feet, skiers and riders could trigger small to large wind slabs up to 3 feet deep. These wind slabs could step down to weak layers deeper in the snowpack and become a large persistent slab avalanche.
( Discussion is generated from the previous day's afternoon forecast. )Conditions will be mostly dry except for some isolated snow showers until midnight. The next storm system is fast moving and will bring snow that could become heavy at times between 2 am and noon. After a lull in the precipitation a second wave of moisture, which is slower moving, will arrive in the evening. Winds will back to the southwest, increase to 25 miles per hour with higher gusts and bring warmer air into the region. Tomorrow's temperatures are expected to rise into the 20s.In the Greys River and Togwotee Pass areas conditions are dangerous and are likely to remain that way. Recent new snow lies upon older faceted persistent weak layers and is unstable on steep slopes. Slab avalanches can be easily triggered by the weight of a person. The new snow is deep and therefore this situation can produce large, dangerous slab avalanches that could be three to six feet deep. In these areas the general avalanche hazard is expected to be considerable. In the Teton forecast area visibility has been limited. Several very large slab avalanches are known to have occurred in response to recent snowfall and wind events. With more snow and wind in the forecast conditions are expected to remain dangerous at the upper elevations where the general avalanche hazard is expected to be considerable. A moderate hazard is anticipated at the mid and lower elevations. Large to very large slab avalanches are possible and could be 2 to 5 feet deep.
