Dangerous avalanche conditions exist at the upper elevations of the Tetons where the danger has evolved to the low range Considerable. Although natural avalanche activity is now unlikely, backcountry riders or skiers still have the potential to trigger large or very large avalanches in very steep terrain involving weak snow buried in early December. It is important to note that tracks on a slope are not an indication of stability and failure could still occur when a person impacts a particularly thin and weak spot in the snowpack. Careful snowpack evaluation can help to determine the presence and extent of the persistent weak layer and cautious route finding remains the best way to avoid involvement in a high consequence slide. At the mid elevations, the possibility for similar but smaller avalanche events continues on certain aspects and avalanches at low elevations are unlikely today.
In very steep terrain, the potential continues for humans to trigger hard slab avalanches involving failure of weak snow layers buried on December 5th. If failure occurs, avalanches could have average slab depths of three to six feet at the upper elevations and up to three feet at the mid elevations on north to east aspects.
Active winter weather returns overnight with five to seven inches of new snow forecast for the mountains by morning and another inch or three tomorrow. Southwest flow will again favor the Tetons and the Salt River Range with the most snowfall. Ridgetop wind speeds are forecast to be forty to fifty miles per hour with gusts to seventy-five.New snow will add another three quarters in an inch of water weight to an already dangerous persistent slab problem. Wind loading of lee slopes will add further stress to the weak layer deep in the snowpack as well as building a slab on any near surface facets that have developed during the recent sub-zero temperatures. The combination of sensitive wind slabs and further loading of the deeper, persistent weak layer will keep the avalanche danger elevated tomorrow. You can expect fresh wind slabs one to two feet .. I think just to one foot and can change in am if it really snows… thick by morning plus the lingering concern of triggering a very large avalanche on the deeply buried facets. Avalanches with a destructive size of two and three (out of five) have been triggered remotely on this layer. Tomorrow, all forecast areas will very likely have a Considerable danger rating. Elevations below 8,000' which still lack much snow, continue to have a Low danger rating.
