Avalanche conditions continue to be dangerous. Widespread instability exists as slabs of cohesive snow lie over persistent weak snow near the base of the snowpack. Do not allow sunny skies and high holiday traffic compromise good decision making and be sure to evaluate snow and terrain carefully. Avalanches below 7500 feet are unlikely.
Above 7500, the potential for humans to trigger slab avalanches with depths to four feet poses a serious threat to backcountry users. If triggered these dangerous slabs will fail on a layer of faceted snow near the ground that persists on all aspects. These slabs could be triggered by the weight of a single person. On Wednesday, a moose triggered a slide in the South fork of Spread Creek.
( Discussion is generated from the previous day's afternoon forecast. )Dry and clear conditions are in store for Friday as high pressure builds over the area and inversion conditions develop. Temperatures will be coldest in the valleys with morning temperatures near twenty below zero. Morning fog and low clouds are likely to develop over the Jackson and Star Valleys. High elevations should start in the single digits and warm into the upper teens. The general avalanche hazard is expected to Moderate. Make no mistake, although the likelihood of triggering has lessened, the weak snow is preserved and large dangerous avalanches could still be triggered by one person who hits a particularly weak spot in the snowpack. These slabs are even more susceptible to failure by larger triggers such as snowmobiles or groups of skiers. Persistent weak layers demand conservative decision making and a wide margin of safety is warranted.
