Riders and skiers should be aware of two types of avalanche concerns in the backcountry today. Wind slabs formed by recent snow and strong winds lie at all elevations. Also, on certain aspects at the high elevations the possibility continues to trigger very large and dangerous avalanches involving weak snow near the base of the snowpack. This early season weakness remains a threat and failure by the weight of a single person is still possible, even after a slope has been previously tracked. Careful snowpack evaluation and cautious route finding are essential today.
Above 9000 feet, deep hard slabs continue to be a concern on northwest to northeast aspects. A single skier or rider could impact this persistent weak layer and trigger a very large, hard slab avalanche with depths to five feet. Large triggers, such as snowmobiles, are more likely to cause failure of this weak layer.
Recent snowfall and strong south-southwest to west winds have formed soft slabs in steep leeward slopes near ridgelines and under cliff areas where drifting snow accumulates. These slabs could be triggered in very steep terrain with depths up to three feet.
( Discussion is generated from the previous day's afternoon forecast. )Skies are to be partly clear through Thursday with occasional isolated mountain snow showers or flurries possible. West winds will remain relatively strong with averages between fifteen and twenty five miles per hour. Temperatures will be warmer with mountain highs in the upper teens to low twenties. In the Tetons, the general avalanche hazard will be Moderate above 7500 feet and low below that elevation. In the Togwotee Pass and Southwest Trails areas, the hazard will remain Considerable above 9000 feet and Moderate below. The avalanche problems remain the same in all areas. Deep weaknesses in the snowpack persist and very large avalanches could be human triggered on these old layers. The difference in the rating is related to the likelihood of triggering avalanches on this layer. In the Tetons where the most snow has fallen, these slabs are becoming harder to trigger than in the other areas. This is partly due to depth but also due to the fact that recreation involving larger triggers, specifically snow machines are far more prevalent in the other areas. In all areas, wind slabs with depths of one to three feet could also be triggered in very steep avalanche terrain.
