Since Saturday, November 7, there has been up to 3 feet of snow with almost 3 inches of water and over 20 inches of that snow fell since Tuesday afternoon. Above 9,000 feet on northerly aspects, where the recent snow fell upon preexisting snow from October, it is possible for backcountry travelers to trigger slab avalanches up to 2 feet in depth. In most areas below 9,000 feet, avalanches are unlikely. Keep in mind, early season conditions exist and even a small slide or sluff could have severe consequences if a victim is swept into bare, rocky terrain.
Southerly to westerly ridgetop winds have gusted into the 20s to 40s and formed wind slabs on leeward slopes. At the upper elevations, where these slabs have formed over a melt-freeze crust from the October snow, wind slab avalanches are possible. To travel with caution, avoid wind loaded slopes and check for old snow surfaces below the new snow.
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.
