Numerous surface slabs were triggered or released naturally yesterday. Off the northern boundary of the Jackson Hole Mountain Resort, a skier triggered an eighteen inch soft slab which carried him several hundred feet and partially buried him. Three other people were caught but not buried in similar slides. South of the ski area boundary, a very wide slide on No Name peak released naturally with a crown depth up to four feet. Similar slides are likely today along with deep persistent slabs which could have depths up to eight feet. As the day progresses, warming temperatures and the additional weight of dense snow will make these slides more likely. These conditions mandate a conservative approach to terrain choices. With above freezing temperatures and rain in the forecast, natural wet slides will be possible at the lower elevations.
Strong westerly ridgetop winds have created dense wind slabs in exposed terrain at the mid and upper elevations. Skiers and riders could trigger these slabs to depths up to four feet. These slabs could step down to persistent weak layers deeper within the snowpack.
At the lower elevations, where overnight lows remained above freezing, wet slabs could release naturally. Rain and warming temperatures will increase the likelihood of these slides as the day progresses.
Dense snowfall continues to add weight to persistent weak layers formed during drought periods earlier in the season. Three different events have occurred over the last few days with two of them being remotely triggered. These slabs could have depths up to eight feet and the consequences of being caught would most likely be fatal.
The westerly flow aloft will gradually veer to the northwest overnight as an upper level disturbance passes through the region. Light snowfall will continue overnight, significantly decrease by morning and end by evening with accumulations of a couple inches possible. On Friday temperatures will warm into the upper 20s at 10,500 feet and into the upper 30s at 6,500 feet. Winds will be southwest at 5 to 15 miles per hour.Very significant avalanche hazard exists at all elevations. Killer deep slabs with depths of 6 to 12 feet and large surface slabs with depths of one to four feet could be easily triggered by the weight of a single person. Very large natural releases are possible. Wet slides are possible at the lower elevations. Failure to respect these conditions could result in death. In these conditions it is best to back off from bold terrain and live to ski or ride another day. The general avalanche hazard is expected to be CONSIDERABLE at all elevations.
