Dangerous avalanche conditions exist. Approximately two feet of snow has fallen in the Tetons over the last two days. Strong winds have accompanied this snowfall, forming wind slabs at the mid and upper elevations. In many areas, these slabs lie on smooth firm surfaces formed by very strong winds earlier in the week. These wind slabs could be easily human triggered, will increase in sensitivity today and could release naturally. Some potential also exists for avalanches involving old weak snow layers, particularly where the snowpack is shallower like the lower elevations. Evaluate the snowpack carefully, particularly the interface under yesterday’s storm and make conservative decisions today.
Wind slabs could fail on Thursday's firm snow surfaces or on density breaks within the new snow with depths up to three feet in steep wind-loaded starting zones These slabs will increase in size and sensitivity as they are further loaded today.
Persistent slab avalanches, involving older weak layers, remain a possibility. These weaknesses are more likely to be initiated in areas where the snowpack is fairly shallow and could have depths of two to four feet.
Expect overcast skies and some light snow showers overnight. Snowfall will taper off during the day on Sunday, and skies will be partly to mostly cloudy by the evening. Mountain temperatures will drop into the lower singled digits as an arctic airmass drops down from the north. Daytime highs will only climb into the upper single digits. Southwesterly to westerly ridgetop winds will range from 5 to 15 miles per hour.Avalanche conditions are dangerous across the region, and the general avalanche hazard is expected to remain Considerable on Sunday. In steep, wind loaded terrain above 7,500 feet, skiers and riders could trigger soft wind slabs that formed over the last 3 days. These slabs are likely to range in depth from 1 to 3 feet with the Tetons on the higher end of the spectrum. On a variety of aspects and elevations, persistent slab avalanches up to 4 feet deep remain a concern in the Tetons, primarily in terrain that has fairly shallow snow depths. The Togwotee Pass snowpack is much shallower than the Tetons, and weak, faceted snow is widespread. There, backcountry travelers could easily trigger similar sized slabs on most aspects and elevations. The snowpack in the Southwest Trails varies between the other two forecast zones, and human triggered persistent slabs will be possible on many slopes. Don’t let the new snow and the holiday weekend impair your judgement. Conservative terrain choices and excellent snowpack evaluation will be necessary for safe travel in avalanche terrain on Sunday.
