Travel in avalanche terrain is not recommended today. In favored areas of the Tetons, two feet of snow has fallen in the last twenty four hours and three and a half feet has fallen in the last three days. Additional snowfall today and southwest winds will further load new and old instabilities in the snowpack and natural avalanche activity is expected at the mid and upper elevations and possible at the lower elevations. Backcountry travellers who venture into steep terrain are very likely to trigger slab avalanches that could be large in size and are expected to run long distances. Wyoming Department of Transportation conducted overnight mitigation efforts on Teton Pass, triggering slides in Glory Bowl and in the Beaver Slide.
Sustained snowfall and southwest winds have created wind slabs. These slabs could fail on density breaks within the recent snow with varying depths up to four feet at the higher elevations and up to two feet in depth at the lower elevations. Slabs will continue to increase in volume and depth as the day progresses. These soft slabs will be very sensitive and are expected to run long distances.
Buried layers of faceted snow exist in the snowpack. Large to very large persistent slab avalanches could fail on these layers with depths from 3 to 5 feet at the higher elevations and 1 to 3 feet at the lower elevations. These dangerous slabs could fail naturally or be triggered by the weight of a single person or the release of a surface slab.
Cold air will move in tonight and bring temperatures to the low single digits by sunrise at all elevations. Daytime highs are forecast to the near ten in the mountains and the upper teens in the valleys. Winds are to veer to the northwest with five to fifteen mile per hour averages. Given the forecast temperatures and moderate to light winds the avalanche danger is expected to be Considerable at all elevations and in all forecast areas. The likelihood of slabs releasing naturally is expected to decrease however DANGEROUS conditions will continue as it will remain likely for a skier or rider to trigger potentially large slides in steep avalanche terrain on any aspect. Slab depths could reach as much as four feet and are most likely to fail on the interface between the recent snow the layer that was buried on Saturday although other weaknesses deeper in the snowpack exist and could also fail or simply be entrained in a moving slide. Check the morning forecast and monitor conditions in the field as the hazard could increase to High if sunshine allows temperatures to spike higher than currently forecast or if the winds are stronger than anticipated. The light snow that fell during generally consistent southwest winds will be very susceptible to transport by northwest winds and could quickly load steep slopes in different areas, causing natural releases.
