The general avalanche hazard is moderate above an elevation of 8,500 feet and low below that elevation. Yesterday a snowmobiler died in an avalanche near Sheep Pass in the Salt River Range. Information on this tragic accident is limited at this time. Persistent weak layers exist at the interface beneath the snow that has accumulated since December 11 and old snow surfaces that formed during a long dry period. On avalanche prone slopes, the weight of a single person could trigger a slab avalanche on this interface or on other deeper buried layers of faceted snow. At the higher elevations these slabs could be large enough to seriously injure or fully bury a person. Evaluate steep slopes carefully and anticipate the potential consequences of triggering a large slab avalanche or even a small avalanche in terrain traps or on slopes with low snow hazards that can cause serious trauma.
At the higher elevations large slab avalanches formed by southwest to west winds could be human triggered on steep avalanche prone slopes. These slabs could be up to two feet deep.
( Discussion is generated from the previous day's afternoon forecast. )Overnight, a transitory ridge of high pressure will build ahead of a fast-moving short wave trough. Cloud cover is expected to increase, and by tomorrow morning, skies should be mostly cloudy. Light snowfall will develop across Western Wyoming with accumulations of one to four inches. Mountain temperatures will be in the teens and valleys should climb into the twenties. Westerly ridgetop winds are expected to be 15 to 20 miles per hour with higher gusts. The general avalanche hazard above 8,000 feet is expected to be Moderate. Skiers and riders could trigger slab avalanches one to two feet deep, where these slabs lie over persistent weak grains. The snowpack structure across the forecast area varies, and where a slab has formed dangerous avalanche conditions could exist. Below 8,000 feet, where large grain facets and buried surface hoar continue to be reactive, the small soft slabs will likely be isolated to terrain features steeper than 35 degrees. Careful terrain management is essential as the snowpack continues to adjust to the new load.
