Avalanche Forecast
Regions: Crawford, Dogtooth, East Purcell, Moyie, Purcells, St. Mary, West Purcell.
There is still uncertainty about the reactivity of deeper weak layers.
Steer clear of rocky, thin, and shallow areas where triggering is possible.
Confidence
Moderate
Avalanche Summary
Explosive testing on both Tuesday and Wednesday triggered many small ( size 1 to 1.5 ) windslab avalanches. These all occurred between 2000 and 2500 meters.
A rider accidentally triggered a small avalanche from a shallow alpine slope on Repeater Peak near Golden, getting carried through cliff features and a gully. The failure plane is suspected to be the persistent weak layer down 60 cm. Read the MIN report here.
Snowpack Summary
In sheltered areas, 20 to 75 cm of settled snow is present. Previous southwest winds have redistributed this snow, creating deeper deposits on leeward slopes at higher elevations. The surface snow varies, with surface hoar and facets on northerly slopes and a thin, breakable sun crust on southerly slopes.
A weak layer buried in early December can be found down 40 to 90 cm. On shaded slopes, it consists of weak surface hoar or faceted crystals, while on south-facing slopes, it combines a sun crust with facets.
The snowpack base is composed of a thick crust and facets in many areas.
Weather Summary
Friday Night
Partly cloudy with isolated flurries 1 to 2 cm. 5 to 10 km/h south ridgetop wind. Treeline temperature -4 °C.
Saturday
Partly cloudy, with light snowfall 1 to 2 cm. 5 to 10 km/h southwest ridgetop wind. Treeline temperature -3 °C.
Sunday
Partly cloudy, with light snowfall 1 to 5 cm. 5 to 10 km/h west ridgetop wind. Treeline temperature -5 °C.
Monday
Partly cloudy, with light snowfall 1 to 5 cm. 5 to 10 km/h north ridgetop wind. Treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Loose 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