At the upper elevations, this week’s snow lies over a melt-freeze crust formed by the October snow. Where the preexisting snow can be found, it is possible for backcountry travelers to trigger a slab avalanche up to 2 feet in depth. In most areas 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 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 at the base of the snowpack.
A winter storm warning has been issued by the National Weather Service. Snow fall amounts of up to 18 inches are possible in the mountains. Strong southwest winds will veer to the northwest during the day as the center of this weather system moves east. Temperatures will be in the teens in the mountains. A significant snow event and strong winds will be rapidly loading leeward aspects and increasing the avalanche hazard. Conditions are expected to become dangerous at the higher elevations on steep avalanche prone slopes where the recent new snow lies upon old October snow surfaces. In those areas, large slab avalanches are possible. These dangerous slides could release naturally or be triggered by a skier or rider. Slabs depths of two to as deep as four feet are anticipated. Conservative terrain choices are warranted. The general avalanche hazard is expected to be considerable at the higher elevations (9,000 to 10,500 feet), moderate at the mid elevations and low below an elevation of 7,500 feet.
