Recent snowfall and southerly to westerly winds continue to create dangerous avalanche conditions. Above 8,500 feet, human-triggered slab avalanches are likely on steep wind-loaded slopes. Increasing wind speeds throughout the day will form wind slabs at the mid and upper elevations and possibly small isolated pockets at the lower elevations. Over the past 3 days, the Togwotee Pass forecast area has received close to 20 inches of snow with almost 2 inches of water. Backcountry travelers should use caution today and be mindful of steep terrain, especially over terrain traps with the significant amount of loose snow that could move down the slope.
Strong winds today will increase the hazard by loading slopes and forming slabs that are most likely to be found at the upper elevations on leeward slopes and in large start zones. Although, gusty conditions today could form areas of slab on terrain feature including many aspects and elevations. The slab depths could be 2 feet and if triggered, these avalanches will entrain the new snow.
Weak, faceted snow from the December 5 interface could result in larger avalanches up to 3 feet in depth. The increased load over the past 3 days has added stress to the snowpack. These persistent slab avalanches could be triggered by the weight of a single person or the impact of a wind slab. Careful evaluation of the snowpack is essential for assessing this potential avalanche problem.
( Discussion is generated from the previous day's afternoon forecast. )Snowfall is expected through tomorrow night with accumulations of 8 to 16 inches in the Southwest Trails, 7 to 14 in the Tetons, and 3 to 6 on Togwotee Pass. Southwesterly ridgetop winds overnight will veer to the west tomorrow morning and are expected to be 20 to 30 miles per hour with higher gusts. Mountain temperatures will be in the teens and valleys in the twenties. At the upper elevations, the avalanche danger will remain Considerable as snowfall and steady winds continue to impact the area and create dangerous avalanche conditions. On steep wind-loaded starting zones, it will be likely for skiers and riders to trigger slab avalanches 1 to 3 feet in depth. If triggered, these slides could entrain new snow and grow in size. In isolated areas, deeper slab avalanches up to 4 feet in depth could be triggered on old faceted snow that formed earlier in the season.
