Skiers and riders have the potential to trigger wind slabs that formed earlier in the week. These slabs can be found in steep leeward terrain that was loaded by Monday’s strong and varying winds. Backcountry travelers are encouraged to approach avalanche terrain carefully in order to identify and avoid steep areas where this loading has occurred. Also be wary of terrain traps such as ditchs or creek areas where small slides can still bury a person. Above 8000 feet, a slight chance also exists for larger triggers to initiate deep hard slabs involving weak snow near the base of the snowpack.
Soft to hard slabs formed during Monday's strong winds and snowfall could be human triggered in steep terrain with depths to two feet. Monday's heavy snowfall occurred at all elevations and amounts varied by specific location. Evaluate recent snowfall, wind loading and terrain carefully.
A deep slab avalanche was observed to have occurred on a northwest aspect of Palisades Peak in the Snake River Range on February 1st. Deep persistent slab avalanches 4 to 7 feet in depth are unlikely except in isolated locations. They could be triggered when a significant load impacts a thin area of a slope. Such larger triggers include large cornice drops, snow machines or possibly a moving wind slab.
( Discussion is generated from the previous day's afternoon forecast. )Clouds will be on the increase overnight. A trace of snow could fall by sunrise. During the day, snowfall will increase in intensity and could be heavy during the afternoon. Sub-zero temperatures are expected at all elevations in the morning. Slightly warmer air is to come in with the precipitation, allowing temperatures to warm to the teens. West winds are to have 10-20 mph averages during most of the day and then increase in the later afternoon. The general avalanche hazard will be Moderate in the Tetons above 9000 where wind slabs to eighteen inches could be triggered in steep terrain. Below 9000 the danger will be Low and avalanches are unlikely except for isolated pockets in the steepest terrain. In the Togwotee Pass and Southwest trails areas, the danger rating will be Moderate at all elevations. More snow fell yesterday in these locations and the possibility exists for human triggered wind slabs at all elevations. These slabs are likely to release as pockets with depths to two feet. The remote chance also continues in these areas to trigger hard slab avalanches on deeply buried layers above 8000 feet. A larger trigger such as a snow machine hitting a thin, weak spot or the movement of a wind slab is most likely to trigger such an event.
