Recent light snowfall and winds have formed wind slabs at the high elevations. These slabs will be sensitive to human triggers on steep, wind loaded terrain features. In isolated areas at the mid and upper elevations, the possibility also continues to trigger deep hard slabs on old persistent weak layers near the base of the snowpack. Several of the newer wind slabs have been reported lately. Although recent activity involving the deep slab has not occurred, trigging these dangerous remains possible and is likely to carry severe consequences. Conservative terrain choices are warranted. Avalanches are unlikely at the lower elevations.
At the upper elevations several days of southwest to northwest winds have created pockets of surface slab up to two feet in depth. These slabs could be human triggered in steep avalanche starting zones and cliff areas.
Above 7500 feet, hard slabs with depths to five feet lie upon persistent weak layers of faceted snow. In isolated areas on all aspects these dangerous slabs could be released by large triggers like a snowmobile or a groups of people. Some potential may remain for these slabs to be triggered by the weight of a single person in areas where the overlying slab is thin. Previous tracks and the lack of recent avalanche activity are not indications of stability.
Snow is to develop overnight and continue on Thursday with the highest precipitation rates expected between 5am and 11am. By the evening four to six inches are expected in the Tetons with higher amounts in localized areas and slightly lower accumulations are expected in the Togwotee and Southwest trails areas. Winds are to be southwesterly with 15-25 mph averages and temperatures should be slightly cooler with highs near twenty degrees.The general avalanche hazard is expected to be Moderate above 7500 feet and low below that elevation. New snowfall and southwest winds are expected to form new wind slabs as well as add load to existing wind slabs. In any higher terrain, accumulating snowfall will add load to the slabs lying on persistent weak layers. If significant enough snowfall occurs these slabs could become more sensitive to triggers, and these potential triggers include the easier to trigger wind slab avalanches.
