The avalanche problem of primary concern remains persistent slab. Backcountry travelers could trigger slab avalanches one to two feet deep in steep, wind-affected terrain above 9,000 feet that held snow from early October. To avoid this threat, determine if the October rain crust and faceted snow combination is present, and assess the slab properties of the overlying snowpack. As the day progresses, monitor the effect of the wind on the snowpack, and move to more sheltered terrain if new slabs begin to develop. In terrain where the crust/facet combination is absent, avalanche activity is unlikely.
The combination of weak, faceted snow lying on a strong rain crust primarily exists on northwesterly through northeasterly aspects above 9,000 feet. Backcountry travelers could trigger slabs failing on this layer to depths up to two feet in steep, wind-affected terrain.
( Discussion is generated from the previous day's afternoon forecast. )Expect increasing cloud cover overnight and into Saturday as the first in a series of fast moving Pacific weather systems hits the region late in the day on Saturday. Overnight lows in the mountains will dip into the single digits before rising into the mid teens during the day. Westerly ridgetop winds will increase to 15 to 25 miles per hour.The general avalanche hazard is expected to remain MODERATE on Saturday with persistent slabs continuing to be the primary avalanche problem of concern. Two ingredients are necessary to be exposed to this threat. First, faceted snow above the October rain crust needs to be present to provide a weak layer and a bed surface. This combination primarily exists on westerly through northerly to easterly aspects above 9,000 feet and dips below 9,000 feet in mostly shaded terrain. Second, there needs to be a strong enough slab to propagate failure of the faceted snow. Skiers and riders could trigger these slabs to depths of one to three feet. In terrain where the facet/crust combination is absent, avalanche activity is unlikely.
