Avalanche Forecast
Regions: Crawford, Dogtooth, East Purcell, Moyie, Purcells, St. Mary, West Purcell.
A calm weather day marks the end of the year.
Uncertainty remains around the reactivity of deeper weak layers.
Continue to avoid rocky, wind-affected areas where triggering is possible.
Confidence
Moderate
Avalanche Summary
On Sunday, skiers accidentally triggered a small storm slab (size 1) on a southeast alpine feature near Panorama. Several natural small loose avalanches were also reported from steep terrain., some induced by solar radiation.
In the Bugaboos, large wind slabs (size 2) were triggered by cornice falls on northerly alpine slopes.
If you head out in the backcountry, let us know what you are seeing by submitting a MIN report!
Snowpack Summary
In sheltered areas, 15 to 30 cm of recent snow can be found. The previous southwest wind has redistributed this snow, forming deeper deposits on leeward slopes at higher elevations. Surface snow consists of surface hoar crystals and facets on northerly slopes and a thin sun crust on southerly slopes.
A weak layer buried in early December is now about 40 to 90 cm below the surface. This layer varies between weak surface hoar or facetted crystals on shaded slopes and a sun crust with facets on south-facing slopes. Professionals are still concerned about its potential instability.
The base of the snowpack is made of a thick crust and facets in many areas.
Weather Summary
Monday Night
Partly cloudy, with isolated flurries. 10 to 20 km/h west ridgetop wind. Treeline temperature -12 °C.
Tuesday
Partly cloudy, with isolated flurries. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -12 °C.
Wednesday
Partly cloudy, with isolated flurries. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -14 °C.
Thursday
Partly cloudy, with isolated flurries. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -14 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid shallow snowpack areas, rocky outcrops, and steep terrain where triggering is most likely.
- Be especially cautious as you transition into wind-affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Pay attention to the wind; once it starts to blow, sensitive wind slabs are likely to form.
Avalanche Problems
Persistent Slabs
In the mid-snowpack, buried surface hoar or facets may pose a risk on north-facing slopes, while a buried sun crust could be reactive in south-facing areas. In shallow snowpack areas, facets at the base of the snowpack are generally weak.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 3
Wind Slabs
Recent snowfall and wind have formed wind slabs in lee and cross-loaded areas. These slabs may remain sensitive to human triggering on steep, convex and unsupported slopes.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2