Avalanche conditions are dangerous and ripe for serious avalanche accidents. Large to very large avalanches could release naturally or be triggered by humans on a variety of aspects at all elevations. Avalanches can occur on steep slopes that slide infrequently. Last night a slide released naturally on Teton Pass and struck a vehicle. During the previous two days two people were caught, carried long distances and seriously injured in separate avalanche accidents outside of the boundary of the Jackson Hole Mountain Resort. On Tuesday an avalanche released naturally on a hillside in Coyote Canyon and hit parked vehicles in a school parking lot. Yesterday afternoon the Wyoming Department of Transportation explosively triggered a large slab avalanche on East Gros Ventre Butte that ran across the highway. An avalanche just north of the Mile 151 slidepath south of Jackson ran to the edge of the roadway. Monitor conditions. Sunshine and/or increasing winds could quickly elevate the avalanche hazard. It is important to realize that the consequences of being caught in a large slab avalanche are likely to be severe and that most recreational avalanche fatalities occur during periods of considerable or moderate hazard. Conservative terrain choices and excellent route finding skills are essential for safe travel in avalanche terrain.
On steep slopes large to very large soft slab avalanches could release naturally or be triggered by the weight of a single person or an animal (wildlife). These dangerous slabs may run long distances and could be two to four feet deep at the mid and upper elevations and up to two feet deep at the lower elevations.
Buried layers of faceted snow exist in the snowpack. Large to very large persistent slab avalanches could fail on these layers with depths from 3 to 5 feet at the higher elevations and 1 to 3 feet at the lower elevations. These dangerous slabs could fail naturally, be triggered by the release of a surface slab, be triggered by the weight of a single person or by wildlife.
This evening will be dry with clear skies. These conditions will allow temperatures to drop to 15 to 30 below zero in the coldest valley locations. Skies will be mostly sunny on Friday with areas of patchy morning fog. Temperatures will be inverted with daytime highs rising into the teens. Winds will back to the southwest at 15 to 20 miles per hour with higher gusts. Large slab avalanches could be triggered by the weight of a single person on a variety of aspects and elevations. These slabs could fail within the recent storm snow or step down to weak layers of faceted snow. The general avalanche hazard is expected to be considerable. Conservative terrain choices and excellent route finding skills are essential foe safe travel in avalanche terrain.
