Togwotee Pass

Southwest wind and an additional two to four inches of new snow in the past 24 hours continued to load avalanche start zones near ridgelines. This recent loading combined with the previous three days snowfall has added stress to weak layers of snow which sit near the base of the snowpack. The remotely triggered and destructive hard slab avalanche which occurred yesterday afternoon on the west side of the Tetons indicates the potential for very large avalanches to occur. This avalanche was triggered from low angled terrain near a steep, wind-loaded ridgeline at around 9,600’. Widespread reports of collapses in the snowpack in middle elevations serves as a reminder that this persistent slab remains a potential problem there as well. Today is a good day to travel conservatively and allow the buried weak layers time to adjust to recent loading. Avalanche danger is Considerable today above 8,500' where wind slabs are still fresh. Very large persistent slab human-triggered avalanches are also possible in isolated terrain. Carefully evaluate the terrain where you plan to ride or better yet, stick to lower angled slopes where these slabs don’t exist. Lower elevations have less snow coverage and lack the weak layers of snow. Low avalanche danger exists there.

( Discussion is generated from the previous day's afternoon forecast. )This evening, an Arctic cold front will push through western Wyoming and bring with it a brief period of snow and high wind, which will shift to the northwest, as the front passes. Only an inch or two of snow will arrive with the front but temperatures behind it will drop significantly. Expect highs in the mountains tomorrow to struggle to reach single negative digits after overnight lows of -10 to -15. Frigid temperatures and very little, if any, wind loading are expected tomorrow. These factors will make natural avalanches trend towards unlikely in the Tetons and Togwotee Pass and so reduce the overall avalanche hazard in those areas to Moderate. The Grey’s River area appears to have a potentially more active weak layer, which has received the same or greater stress from recent storm snow and wind loading. Though we do not have strong confidence that natural avalanches will occur there, the increased thickness of slabs there, which could be up to five feet thick, and the potential to trigger these from a distance or from below shouldn’t be ignored. These factors result in a Considerable danger rating at upper elevations, on steep and wind loaded slopes above 8500 feet in that zone.