Yesterday, a skier triggered a small surface slab on a southeast facing slope in the Rock Springs drainage south of the Jackson Hole Mountain Resort. Similar slides involving recent snowfall are possible today. A persistent weak layer of faceted snow near the base of the snowpack presents a much more serious problem, and slab avalanches failing on this weak layer will likely carry serious consequences. Collapses and cracking are indications of instability and should be an alarm to avoid steep slopes. At the lower elevations, the snowpack is mostly stable and avalanches are unlikely.
Persistent slabs lie upon a base of weak, faceted snow on a variety of aspects above 7,500 feet. Skiers and riders traveling into steep, avalanche terrain could trigger these slabs with depths up to three feet. Persistent slabs pose a significant threat to backcountry users as they can remain unstable for days or weeks. Previous tracks are also not an indication of stability.
The chance for light snow showers will increase overnight as the stream of Pacific moisture shifts to the east and temporarily resides over Western Wyoming. Overnight lows in the mountains will be in the low teens before rising into the upper teens during the day. Southwesterly to westerly ridgetop winds will range from 20 to 30 miles per hour.The general avalanche hazard is expected to remain CONSIDERABLE on Sunday. The persistent weak layer of faceted snow near the base of the snowpack continues to present a serious threat to backcountry travelers. Skiers and riders venturing into steep avalanche terrain could trigger slab avalanches failing on this weak layer on a variety of aspects. These slides could be up to three feet deep in the Tetons and reach depths of two feet in the Greys River and Togwotee Pass areas.
