Up to 11 inches of new snow with three quarters of an inch of moisture has fallen in the southern Teton Range since about 10 PM last night. At the upper elevations and down to around 8,500 feet on shaded northerly aspects at the mid elevations this new snow has fallen upon slick old snow surfaces. Human triggered and naturally released loose snow and wind slab avalanches are possible on steep slopes where this new snow is poorly bonded to the old snow. These avalanches could be large enough to injure or bury a person. The consequences of being caught in a small avalanche during early season conditions are amplified due to the shallow snow cover. Avalanches are not likely where last nights new snow has accumulated on bare ground.
At the upper elevations westerly winds at 25 to 30 with gusts to 40 miles per hour will be forming pockets of soft slab up to 18 inches in depth on leeward aspects. In steep terrain these slabs lie upon slick old snow surfaces and could be human triggered or release naturally.
Loose snow sloughs are possible on steep slopes where last nights new snow lies upon slick old snow surfaces. These sloughs could be triggered by a person or release naturally.
Clear skies will prevail as a high pressure ridge builds into the region. Temperatures will be in the teens and 20s in the morning and rise into the 30s and 40s during the day. Gusty west-northwest winds will continue overnight and decrease and back towards the west-southwest on Sunday.Some instability will linger on steep wind loaded slopes at the upper elevations. The interface between last night’s new snow and firm old snow surfaces will be a potential bed surface for avalanche activity. Pockets of wind slab up to 18 inches in depth could be triggered by the weight of a single person. These wind slabs could be large enough to injure or bury a person. The consequences of going for a ride in a small avalanche are amplified due to the shallow snow cover. Avalanches are not likely in terrain where last night’s new snow lies upon bare ground.
