A skier on Teton Pass was caught and carried but not injured yesterday. This event occurred on a west aspect at an elevation of 8,500 feet. On Tuesday a snowmobiler was buried by an avalanche in the Sheep Creek drainage east of Palisades Reservoir and did not survive. This event occurred on a very steep north facing slope above an elevation of 9,000 feet. Similar events are possible today in all of our forecast areas. Weak layers of faceted snow that formed in December and January are still producing dangerous slab avalanches. This type of hazard is best managed by making conservative terrain choices. Avalanches are unlikely at the lower elevations.
Large to very large deep slab avalanches could be triggered by skiers and riders with depths to five feet on deeply buried persistent weak layers. The consequences of triggering one of these slabs are likely to be severe.
Isolated pockets of wind slab formed by west to southwest winds could be triggered by skiers and riders who venture into steep avalanche starting zones and cliff areas. These slabs could be up to two feet in depth. Even a small slab can be a hazard if it is triggered above a cliff, a terrain trap or in a very steep chute or couloir.
On Friday, expect partly to mostly cloudy skies as the upper level trough moves eastward. Overnight lows in the mountains will be near zero before rising into the low teens during the day. Southerly ridgetop winds will back around to the northwest at 5 to 15 miles per hour.The general avalanche hazard is expected to be Moderate above 7,500 feet. Up there, two to five feet of dense snow resides over faceted layers that formed in December and January. Large triggers, such as snowmobiles, are more likely to be able to impact these deeply buried weak layers. However, the weight of a single skier might be sufficient to trigger one of these dangerous persistent deep slabs if a shallow, weak zone is encountered. Backcountry travelers might also be able to trigger a recently developed pocket of wind slab in very steep, wind-loaded terrain above 9,000 feet. Below 7,500 feet, the snowpack is mostly stable and avalanches are unlikely.
