Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells, West Purcell.
A complex snowpack situation with multiple deep instabilities is best managed through conservative terrain selection.
Confidence
Moderate
Avalanche Summary
Avalanche observations from the alpine in the past three days;
explosive-triggered persistent layers stepping down to the ground and up to size 2 in the Dogtooth range
explosive-triggered wind slabs, size 1.5 in the northwest Purcells
ski cut loose dry to size 1 in the upper snowpack facets near Invermere
Snowpack Summary
A generally well-settled upper snowpack sits atop a complex snowpack with several layers of note.
A layer of buried surface hoar buried 50 to 70 cm deep has been an active avalanche problem. It is less of a concern in areas where a strong, supportive crust exists above the surface hoar layer.
The lower snowpack is typically characterized by sugary, facetted crystals and a crust. Avalanches have been stepping down to this layer.
Snowpack depths at treeline average 70-120 cm with significant variability across the region.
Weather Summary
Saturday night
Mostly cloudy with trace amounts of new snow, ridgetop wind <10 km/h south, treeline temperature -6 °C.
Sunday
Mostly cloudy with trace amounts of snow, ridgetop wind <10 km/h south, treeline temperature -4 °C.
Monday
A mix of sun and cloud, ridgetop wind <10 km/h southeast, treeline temperature -5 °C.
Tuesday
A mix of sun and cloud, ridgetop wind <10 km/h, treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
Avalanche Problems
Persistent Slabs
The primary layer of concern in much of the region is a layer of surface hoar down 50-70 cm. If triggered, avalanches on this layer could step down to deeper weak layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3
Deep Persistent Slabs
A layer of weak facets near the ground may be reactive to human triggering. Especially in shallow, rocky areas in alpine terrain where the layer is not being capped by a crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3