Avalanche Forecast

Fair - Intensity of incoming weather is uncertain on Saturday

Friday: Cloudy with isolated light flurries, freezing levels in valley bottoms, and moderate to strong westerly winds. Saturday: 5-15cm of accumulation expected with freezing levels remaining in valley bottoms, and strong southwesterly winds. Sunday: Another 5-15cm possible with light to moderate southwesterly winds, and freezing levels in valley bottoms.

Recent observations include a few natural and human-triggered small wind slab avalanches up to 40cm thick in lee and cross-loaded terrain. A strong wind-event on Tuesday triggered several Size 2-3 slab avalanches up to 50cm thick in steep north through west facing alpine terrain.

Recent light amounts dry snow has maintained the snow supply for fresh wind slab development and cornice growth. Surface condition in wind-exposed areas is highly variable with scoured areas, sastrugi, and pockets of fresh hard and soft wind slabs. Recent strong winds have created high variability in treeline and alpine areas, with shallow faceted scoured areas, thick wind slabs, and thin trigger points. A weak graupel and/or stellar layer down 25-30cm appears to have been the culprit in recent wind slab avalanche activity. Avalanche professionals are gaining confidence in the mid-December persistent weakness, now down 90-170cm, but concern remains for heavy triggers, such as cornice drops, on steep unsupported slopes. When this persistent weaknesses is combined with weak wind slabs, thin trigger points, and other weaknesses within and under the recent storm snow and at the base of shallow snowpack areas, the result is a highly variable snowpack with the potential for step-down deep slab avalanches.