Above 9,000 feet on north aspects, this week’s snow lies over a melt-freeze crust formed by the October snow. In isolated areas where the preexisting snow can be found, it is possible for backcountry travelers to trigger a slab avalanche 1 to 2 feet in depth. On solar aspects and most slopes below 9,000 feet, avalanches are unlikely. Due to early season conditions and a shallow snowpack, the main hazard remains hidden obstacles and even a small slide could have severe consequences if a victim is swept into bare, rocky terrain.
Southerly to westerly ridgetop winds have formed wind slabs on leeward slopes. At the upper elevations, where wind slabs lie over a melt-freeze crust from the October snow, human triggered avalanches are possible. To travel with caution, avoid wind loaded slopes and check for old snow at the base of the snowpack.
( Discussion is generated from the previous day's afternoon forecast. )Tomorrow cloud cover will increase ahead of another significant storm system. The National Weather Service has issued a Winter Storm Warning starting tomorrow afternoon through Saturday afternoon. Snowfall is expected to develop throughout the day and then intensify overnight. Mountain temperatures will warm into the 20s and the valleys into the 30s. Southwesterly winds are expected to be in the 20s and increase throughout the day with gusts in the 40s by the afternoon. For Friday, the avalanche hazard is expected to be Moderate above 9,000 feet and Low below that elevation in the Teton and Togwotee Pass forecast areas. At the upper elevations, where this week’s storm snow lies over a melt-freeze crust formed by the October snow, it is possible for backcountry travelers to trigger slab avalanches up to 2 feet in depth. In the Southwest Trails / Greys River forecast area, the avalanche hazard is expected to be Low. There, slab avalanches may be found in isolated areas at the highest elevations on north aspects. Due to early season conditions and a shallow snowpack, hidden obstacles remains the biggest hazard and even a small slide could have severe consequences.
