Strong gusty winds and new snow created very dangerous avalanche conditions yesterday. A large slide hit the highway in Hoback Canyon at 4:30 pm and closed the road. A slide that released naturally earlier in the day crossed the groomed trail to Granite Hot Springs. Conditions are still dangerous. Small to very large slab avalanches are likely to be human triggered on steep slopes on a variety of aspects at all elevations and could release naturally. Expert terrain assessment skills and conservative terrain choices are essential for safe travel in avalanche terrain.
Strong and gusty westerly winds have caused extensive drifting and cross loaded a variety of aspects at all elevations. Recently formed wind slabs one to three feet in depth are likely to be easily triggered on steep wind loaded terrain features.
Dangerous deep persistent slab avalanches could be triggered or release naturally where today's winds continue to drift snow into avalanche starting zones. These deep slab avalanches could step down to depths of 4 to 8 feet at the mid and upper elevations and to depths of 3 feet below an elevation on 7,500 feet. These very large avalanches could run full path into lower elevation run out zones.
( Discussion is generated from the previous day's afternoon forecast. )A weak wave will bring several inches of snow to the higher elevations of the Teton Range, Togwotee Pass and the northern portion of the Greys River area overnight. On Wednesday skies will be partly cloudy to mostly clear under a lighter westerly flow. Winds will gust from 30 to 45 on the peaks tonight and decrease to 25 to 30 miles per hour during the day. Temperatures in the mountains will remain in the single digits and teens. At the mid and upper elevations freshly formed wind slabs one to three in depth can be human triggered on steep slopes. Very dangerous deep persistent slab avalanches 4 to 8 feet in depth are also a huge concern. These killer avalanches could be triggered by the weight of a single person or release naturally in response to continued loading by tomorrows winds. Smaller slab avalanches 1 to 3 feet in depth could be human triggered on steep wind loaded terrain features at the lower elevations. The general avalanche hazard is expected to be considerable above an elevation of 7,500 and moderate below that elevation. Expert terrain assessment skills and conservative terrain choices are essential for safe travel in avalanche terrain.
