Avalanche Forecast
Regions: South Columbia.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
MONDAY: Light precipitation in the afternoon combined with colder temperatures and light west winds. TUESDAY: Cold temperatures with light flurries. Winds light to moderate from the west. WEDNESDAY: Cold and clear.
Avalanche Summary
Recent reports indicate loose snow avalanches triggering very easily in steep unsupported terrain on all aspects. Some these avalanches were stepping triggering some of the weaknesses deeper in the snowpack to size 2. On Friday a rider triggered size 2.5 cornice failure on a northeast aspect stepping down to ground in a thin snowpack area. This cornice pulled back to the ridge line.
Snowpack Summary
20-40 cm of low density new snow combined with wind has encouraged additional slab development and cornice growth. This new snow now sits on a variety of surfaces (facets, surface hoar in sheltered areas, wind crust, soft slabs and hard slabs).Avalanche professionals are gaining confidence in the mid-December persistent weakness, now down 110-190cm, 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 a variety of other buried weaknesses the result is a highly variable snowpack with the potential for step-down deep slab avalanches.
Avalanche Problems
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 4
Loose Dry
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2
Cornices
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 3