Sustained westerly to southwesterly winds and 12 to 19 inches of new snow, since late Thursday night, have formed wind slabs on leeward slopes that will be easily triggered by riders and skiers today. If triggered, winds slabs could then initiate failure on deeper weak layers and result in a large to very large avalanche that will likely have unsurvivable consequences. The hazard will remain High at the upper elevations, where these slabs will be large and the most sensitive. If failure on deeper weak layers occurs, these slides could run long distances into lower elevation terrain. Due to the abundant amount of new snow, dangerous sluffs will be possible on steep slopes. Avalanches are likely today and travel in avalanche terrain is not recommended.
Strong westerly to southwesterly winds have formed fresh wind slabs. These surface slabs could be 1 to 4 feet deep and are expected to be sensitive to human triggers. These wind slab avalanches could step down and trigger a much larger deep persistent slab avalanche.
Persistent deep slab avalanches are a serious concern. These dangerous avalanches could be triggered by backcountry travelers or occur naturally. They could also step down from the release of a wind slab avalanche. These destructive avalanches are likely to be 4 and 8 feet deep above an elevation of 7,500 feet and 2 to 4 feet deep below that elevation.
After a chance for a few lingering, scattered snow showers, northerly flow aloft will develop by the morning and partly cloudy skies are expected for most of the day. Overnight lows in the mountains will be in the low negative single digits before rising to around 10 in the afternoon. Westerly to northwesterly ridgetop winds will range from 10 to 15 miles per hour.Avalanche conditions remain dangerous, and the general avalanche hazard is expected to be Considerable on Sunday. Skiers and riders could easily trigger wind slabs ranging in depth from 1 to 4 feet in steep, wind loaded terrain. Persistent deep slab avalanches remain a threat, and involvement will almost certainly result in another fatality. In the Tetons, where the most snow fell, wind slabs will be easily triggered and on the deeper end of the spectrum, and persistent deep slabs will be less likely to be impacted by backcountry travelers. Togwotee Pass is just the opposite. There, significantly less snow fell over the last couple of days, and the underlying persistent weak layers are much more pronounced. The Southwest Trails forecast zone is somewhere in the middle, and both types of avalanches will be likely to be human triggered on Sunday.
