The snowpack in the Southwest Trails forecast zone has areas where buried persistent weak layers continue to be a threat to backcountry travelers. Slabs involving these layers could be triggered above 7500 feet and could be large to very large. The potential also exists to trigger wind slabs formed last week in steep terrain above 9000 feet. Pay attention to sunlight and warming today and monitor their affects on the strength of the upper portion of the snowpack. Below 7500 feet significant avalanche activity is unlikely.
Areas of poor snowpack structure exist, and the weight of a single person may still be sufficient to trigger a deep persistent slab avalanche. Large triggers, such as snowmobiles, or potential cornice failure are more likely than an individual skier to trigger one of these deadly avalanches. Slab depths could vary from three to six feet.
Backcountry travelers venturing onto very steep, wind loaded slopes above 9,000 feet may be able to trigger slabs in steep terrain with depths of one to two feet.
( Discussion is generated from the previous day's afternoon forecast. )Dry weather is to continue tonight and Tuesday. Clouds are to move in late Tuesday with light snow expected Tuesday night. Morning temperature inversions are expected similar to today with morning temperatures near ten degrees at the higher elevations and colder below that elevation. Highs are to reach near thirty at all elevations. Southwest winds with ten to fifteen mile per hour averages will help to mix out the temperature inversion. The General avalanche hazard will be Moderate in higher terrain and Low in lower terrain in all the forecast areas. In the Teton area, the triggering of wind slabs remains a possibility. In the Togwotee Pass area, where the snowpack is wrought with weak snow, deep persistent slab could still be triggered by a single person, causing large to very avalanches. The Southwest Trails area has a potential for either of these avalanche problem types, wind slabs or deep slabs, although avalanches involving the deep weakness are not as probable as in the Togwotee Pass zone. In all areas, larger triggers such as snow machines or naturally falling cornices are more likely to cause failure and increasing temperatures and direct sunlight will weaken slopes and cornices in the late morning and afternoon.
