Avalanche conditions remain dangerous at the mid and upper elevations. Up there, skiers and riders could trigger pockets of recently formed wind slab in steep, wind loaded terrain. These slabs, along with shallow wet slides, will become more susceptible to failure on sunlit aspects as the day warms. Backcountry travelers still have the potential of triggering persistent deep slab avalanches, and being caught in one of these destructive slides could easily result in a fatality. Don’t let blue skies and the weekend impair your judgement; cautious route finding and expert snowpack evaluation will still be required for safe travel in avalanche terrain. Monitor the impact of the sun as the day progresses, and transition to shaded terrain if snow surfaces start to become damp. At the lower elevations, small to large human triggered slab avalanches could fail on faceted snow in steep, avalanche prone terrain.
On steep, wind loaded slopes above 7,500 feet, skiers and riders could trigger recently developed wind slabs ranging in depth from 1 to 2 feet. Light winds, warming temperatures and clear skies will increase the likelihood of triggering these slabs on sunlit aspects in the afternoon, and natural activity may become possible.
Persistent weak layers of faceted snow that formed during the extended dry period towards the end of December, along with basal facets that developed prior to Thanksgiving, were the culprits in a substantial avalanche cycle earlier in the week. Above 7,500 feet, backcountry travelers could trigger persistent deep slab avalanches failing on these weak layers with slab depths ranging from 4 to 8 feet. Below 7,500 feet, skiers and riders could trigger similar slabs with depths ranging from 1 to 3 feet. On sunlit slopes, these slabs may become more prone to failure with daytime warming.
Monday will start with inversion conditions having temperatures near zero in the valleys and in the teens on summits. Highs are to reach the low thirties at all elevations. These high temperatures will be largely dependent on the amount of direct sunshine received which is hard to predict as skies are to transition from clear in the early morning to mostly cloudy or overcast by sunset . South winds are to have averages between ten and twenty miles per hour. The avalanche danger will remain Considerable above 7500 feet in the Teton and Southwest trails areas. In these areas, backcountry riders or skiers could trigger hard slab avalanches involving deeply buried weak layers with depth to eight feet. Warming temperatures and direct sunlight will further weaken the snowpack during the day, making the chance for natural avalanche activity possible. At the Togwotee Pass area, similar, if not worse weak layers persist, however less snow received during the month of January makes both the slab depth and sensitivity of slabs to be lower. Although holding a lower danger rating, caution is advised as snow machines or skiers could still trigger dangerous hard slab avalanches in deep and steep avalanche paths. Below 7500 feet avalanche activity is limited to very steep loaded terrain features where January snow lies over faceted older snow. Isolated pockets with depths to eighteen inches could be triggered at the lower elevations.
