Strong west winds and new snow have formed surface slabs in steep wind loaded terrain. These slabs lie upon crusts formed during the past two sunny days. Skiers and riders could trigger these slabs as well as more dangerous hard slabs that lie upon deeper instabilities within the snowpack. Wednesday a snowmobile triggered one of these hard slabs on south facing avalanche terrain on Angle mountain.
Wind slabs formed overnight as rapid snowfall was accompanied by strong west winds. These soft slabs could be human triggered today with depths to eighteen inches on steep leeward slopes.
Weak layers of faceted snow persist deep within the snowpack. Failure of these layers will produce large to very large hard slab avalanches with depths up to five feet. The consequences of being caught in one of these slides is likely to result in serious injury or death.
( Discussion is generated from the previous day's afternoon forecast. )The storm moving into the area is to bring snow in two waves. The first wave is to impact the area overnight and into Friday morning. Light to moderate snow is expected from this wave. A lull in precipitation is expected through part of the day before heavier snow resumes Friday night into Saturday. Winds on Friday are to be stronger with near thirty mile per hour averages from the west expected. Temperatures are to rise into the mid twenties in the mountains and into the thirties in the valleys. The general avalanche hazard will be Moderate in the Teton and Southwest Trails areas. In the Tetons, wind slabs could be triggered with depths to two feet in very steep and aggressive terrain. Similar events could also be triggered in the Southwest Trails area where the chance also continues for larger loads such as snowmachines to trigger old dangerous hard slabs with depths to six feet.In the Togwotee Pass area, the hazard remains Considerable. Avalanches will be easier to trigger in a shallower snowpack that developed very poor structure during dry periods early in the season. Human triggered avalanches to five feet are possible on a variety of aspects
