Backcountry travelers venturing into steep, wind loaded avalanche terrain at the mid and upper elevations could trigger recently developed wind slabs one to two feet in depth on a variety of aspects. Persistent slabs up to three feet deep still remain a concern on northerly facing slopes above 9,000 feet. These deeper slabs could be triggered directly by skiers and riders, or indirectly by shallower wind slabs stepping down to the faceted snow near the base of the snowpack. Evaluate snow conditions and terrain carefully and avoid areas of concern. Avalanches are unlikely at the lower elevations. The Grand Targhee Resort is closed to uphill traffic as they prepare their slopes for a Friday opening.
Strong west-southwesterly to northwesterly winds over the weekend created dense wind slabs up to two feet in depth on leeward aspects. Backcountry travelers could trigger these slides in steep, wind loaded avalanche terrain. These slabs are mostly likely to be found in exposed terrain near ridgelines. Avoid slopes where the snowpack has a hollow, drum-like feel.
Weak, faceted snow persists at the base of the snow pack on northerly and shaded aspects above an elevation of 9,000 feet. These dense slabs, up to three feet in depth, could be triggered by skiers and riders on this persistent weak layer. Previous tracks on these slopes may not be an indication of stability.
Snowfall is expected to continue tonight and during the day on Wednesday. An additional six to twelve inches of new snow could accumulate by Wednesday evening. Overnight lows in the mountains will drop a couple of degrees back into the low 20s before rising into the mid to upper 20s during the day. Westerly to southwesterly ridgetop winds will range from 20 to 30 miles per hour.Above 7,500 feet, the general avalanche hazard is expected to be MODERATE Wednesday morning and will increase during the day as new snow adds weight to the snowpack. Backcountry travelers could trigger recently developed wind slabs one to two feet deep in steep, wind loaded terrain. On northerly aspects above 9,000 feet, skiers and riders could also trigger older slabs failing on faceted snow near the base of the snowpack. These persistent slabs could also release by stepping down from triggered wind slabs. The general avalanche hazard is expected to be LOW below an elevation of 7,500 feet. The Grand Targhee Ski Resort will be closed to uphill traffic in preparation for a Friday opening.
