Recent snow has been accumulating on a snowpack that has poor structure. Human triggered slab avalanches are possible on steep slopes above an elevation of 8000 feet where the lower half of the snowpack is comprised of weak faceted snow. The distribution of this weak layer is widespread and also mixed with crusts on slopes with a southerly component to their aspect. Avalanches are unlikely at the lower elevations except on isolated terrain features. Cautious route finding and terrain choices remain essential to safe backcountry travel.
At the mid and upper elevations slab avalanches up to two feet feet in depth could be triggered by the weight of a single person.
( Discussion is generated from the previous day's afternoon forecast. )Moderate snowfall is to continue tonight with lingering showers expected through Saturday. Highest accumulations are, again, expected in the Tetons where over six more inches may fall. In the other forecast areas three to six inches is expected. Temperatures are to be slightly cooler while southwest to west winds have averages between fifteen and twenty degrees. The avalanche danger ratings for Saturday will be dependent upon the actual amounts of snow, wind, and weather that is received overnight and where. If enough snow and associated moisture occur, the danger will rise to Considerable. If so, the chance for humans to trigger the persistent slab problem will increase as will the likelihood to initiate loose snow sloughs and very soft surface slabs in steep terrain. Once moving these smaller surface events could also cause failure of the deeper weakness. Avalanches below 8000 feet remain unlikely excepting small, isolated pockets in very steep, shaded terrain.
