Strong northwest winds and new snow have increased the hazard and are creating dangerous conditions, especially at the mid and upper elevations. Instabilities associated with buried layers of faceted snow persist in the snow pack. A cautious approach to terrain choices is warranted.
At the mid and upper elevations strong northwest winds have created wind slabs up to two feet in depth on leeward aspects. At the lower elevations these winds have formed isolated pockets of wind slab up to a foot deep. These slabs could be human triggered and could initiate the failure of deeper persistent slabs.
Dangerous persistent slabs one to four feet deep lie upon weak, faceted snow and hard snow surfaces which formed during the January dry period. The strong northwest winds have continued to add an additional load to these slabs. These slabs could be human triggered today and have some potential to release naturally at the mid and upper elevations.
A disturbance moving south in the northwest flow is forecast to bring another one to three inches of new snow to the mountains overnight. Clearing skies are expected on Friday with temperatures rising into the 20s in the mountains and into the 30s in the valleys. Winds will be northwest at 10 to 20 miles per hour.Instabilities persist in the snowpack in all of our forecast areas and are most prevalent in the Southwest Trails/Greys River area. In steep terrain surface slabs formed by the recent northwest winds and persistent slabs present a significant hazard to backcountry users. Slab avalanches up to four feet in depth could be triggered by humans who venture into avalanche prone terrain. The potential for natural avalanche activity to occur is greatest in the Southwest Trails area but will increase in all areas as air temperatures warm and the sun heats up suspect slopes. The general avalanche hazard is expected to be CONSIDERABLE in the Southwest Trails area and at the upper elevations of the Teton and Continental Divide/Togwotee Pass areas.
