Avalanche conditions remain dangerous. Another cold front moved through last night, and temperatures are starting out 10 to 15 degrees cooler than yesterday morning. Skiers and riders could easily trigger small to large wind slabs in steep, wind loaded terrain. Large to very large persistent slab avalanches remain a threat. One of these slabs recently released naturally in the Southern Tetons at an elevation of 10,000 feet. This very large avalanche involved most of the bowl with aspects ranging from the southwest to the southeast. The crown depth was reported to be six feet, and being caught in a similar slide would be unsurvivable. Don’t let abundant powder and the holiday weekend impair your judgement; conservative terrain choices will be essential for safe travel in avalanche terrain.
Abundant snowfall and southwesterly ridgetop winds have formed wind slabs in leeward terrain. Above 7,500 feet, skiers and riders are likely to trigger these slabs with depths of one to three feet in steep, wind loaded terrain. These slabs might still release naturally.
As the recent avalanche event in the Tetons illustrates, deadly persistent slab avalanches with depths of two to five feet remain a threat. These slabs could fail on buried layers of faceted snow that formed on the surface. In terrain where the snowpack was shallow at the first of the year, basal facets exist in the snowpack, and the overlying slabs could fail to the ground. These slabs could be directly triggered by backcountry travelers or step down from the release of a wind slab.
( Discussion is generated from the previous day's afternoon forecast. )Another cold front will move through the region tonight bringing another 3 to 6 inches of new snow to the higher elevations. Overnight lows in the mountains will be in the single digits before rising into the low teens during the day. Southwesterly to westerly ridgetop winds will range from 15 to 25 miles per hour.Dangerous avalanche conditions exist, and the general avalanche hazard is expected to remain Considerable on Saturday. In steep wind loaded terrain, skiers and riders are likely to trigger recently developed wind slabs ranging in depth from one to three feet. Two types of persistent weak layers of faceted snow remain a concern. Buried layers of surface hoar and near surface facets can be found in the upper portion of the snowpack. Weak, basal facets also exist in terrain that had a shallow snowpack after the first of the year. Prime examples are lower elevations slopes and many areas in the Togwotee Pass forecast zone. These weak layers could fail directly by backcountry travelers or step down from the release of a wind slab. The resulting avalanches could range in depth from 2 to 6 feet and the deeper ones are likely unsurvivable. Don’t let abundant powder and the holiday weekend impair your judgement; conservative terrain choices will be essential for safe travel in avalanche terrain on Saturday.
