The avalanche problem of primary concern remains persistent slab. In steep, high-elevation, wind-affected terrain that held snow from early October, backcountry travelers could trigger slab avalanches one to three feet deep. These slabs have the potential to kill or seriously harm skiers and riders. 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 westerly through northerly to easterly aspects above 9,000 feet. In mostly shaded terrain, this sliding surface and weak layer combination dips below 9,000 feet. Backcountry travelers could trigger slabs failing on this layer to depths up to three feet in steep, wind-affected terrain.
Snow and wind will continue overnight and increase during the day and into the evening. Accumulations of 6 to 12 inches are expected during the next 24 hours. Temperatures will rise into the teens and 20s. Winds will back from the west to the southwest and increase to 25 with gusts to 35 miles per hour.Strong wind, moderate to heavy snowfall and rising temperatures will raise the avalanche hazard at the upper elevations (9,000 to 10,500 feet) in all areas to CONSIDERABLE by morning. The hazard at those elevations will continue to rise during the day and it is expected to increase to HIGH during the afternoon or on Sunday evening. Large dangerous avalanches with slabs depths of two to four feet are likely and could become widespread on east through north to west facing terrain. Travel in avalanche terrain is not recommended during periods of high avalanche hazard. At the mid elevations (7,500 to 9,000 feet) the hazard will increase to MODERATE. Pockets of new wind slab up to two feet in depth could be human triggered on steep slopes. These building surface slabs could release on density breaks, areas of sun crust or buried layers of faceted snow. Due to the low snow depths avalanches at the lower elevations are unlikely except in isolated terrain features.
