Dangerous avalanche conditions continue to exist. Weak snow lies near the base of the snowpack above an elevation of 8000 feet. Backcountry riders and skiers can still trigger slab avalanches involving snow that has fallen since late November that rests above the persistent weak snow. Failure of the weak layer can carry long distances. Yesterday two remotely triggered avalanches were reported in Tetons and similar events could happen today in the Wyoming and Salt River Ranges. Another piece of Drew's Slide, to the south of the Jackson Hole Mountain Resort was triggered by a group on the ridge above the path, and the Great White Hump, north of Teton Pass, was triggered by snowmobilers from below the slope. Use caution in avalanche terrain as slopes are becoming less sensitive and therefore harder to predict. Failure of a slab could occur once a person is exposed in the starting zone, or even after it has been tracked several times. Avalanches below 8000 feet are unlikely today.
Dangerous slab avalanches 2 to 4 feet in depth can be easily triggered by the weight of a single person. These slabs lie over weak basal facets and are most likely to be found on west to north to east facing slopes from 8000-9000 feet and all aspects at higher elevations.
( Discussion is generated from the previous day's afternoon forecast. )Wednesday looks to be slightly inverted and mostly clear. Temperatures in the valleys are to be below zero in the early morning while higher elevations bottom out in the single digits. Highs should reach the twenties at all elevations. On summits, Southwest winds are to have ten to twenty mile per hour averages. The general avalanche hazard will continue to be Considerable above 8000 feet in all forecast areas and Low below that elevation. A persistent weak layer of faceted snow lies near the base of the snowpack anywhere that had snow coverage in mid-November. This layer is weak and the chance continues for the presence of a single person to cause a slope to fail and slide. In some areas conditions remain so fragile that such failure could occur remotely, while travelling above or below the avalanche path. In other steep areas, slabs have become less sensitive which is possibly more dangerous as they may not fail until a person is exposed out in the avalanche terrain. Remember that tracks on a slope are not to be considered an indication of stability when dealing with persistent slab problems. Below 8000 feet or in areas not underlain by the old weak snow layers, avalanches are not expected.
