Avalanche Forecast
Regions: Crawford, Dogtooth, East Purcell, Purcells, West Purcell.
Seek out wind-sheltered terrain below treeline for the softest snow to ride and lowest hazard.
Use caution in wind-affected terrain and avoid steep, rocky slopes with shallow snow cover.
Confidence
Moderate
Avalanche Summary
Last Thursday and Friday, several size 1-2 wind slab avalanches were reported across the Eastern Purcells.
Looking forward, we suspect wind slabs may remain possible to trigger in isolated areas, especially where they overlie a layer of surface hoar.
Reports have been limited. If you venture into the backcountry, please consider submitting your observations to the MIN.
Snowpack Summary
Recent strong to extreme winds from shifting directions have formed wind slabs of varying thickness on lee slopes. While these slabs are gaining strength, they remain possible to trigger in isolated areas. They may rest on a mix of underlying surfaces, including sun crust, surface hoar, and facets.
A surface hoar layer from early January, buried 20–40 cm, may be reactive to human triggers, particularly where it is covered by a wind slab.
A persistent weak layer of facets buried in early December is on average 60 to 90 cm deep. Near Invermere this layer may only be buried 30 cm. Triggering this layer may be possible in isolated areas.
The snowpack base consists of a thick crust and facets in many areas.
Weather Summary
Sunday Night
Clear. 10 km/h north ridgetop wind. Treeline temperature -22 °C.
Monday
Sunny. 10 km/h west ridgetop wind. Treeline temperature -20 °C, with a possible temperature inversion.
Tuesday
Mostly sunny. 30 to 50 km/h west ridgetop wind. Treeline temperature -16 °C.
Wednesday
Mostly sunny. 10 to 20 km/h west ridgetop wind. Treeline temperature -15 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Carefully evaluate steep lines for wind slabs.
- Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
- Be aware of the potential for large avalanches due to buried weak layers.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
Avalanche Problems
Wind Slabs
Recent winds have varied in direction, use caution when entering wind-affected terrain. Wind slabs are expected to be most reactive where they overlie facets, surface hoar or a melt-freeze crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Persistent Slabs
The early December weak layer remains a concern in areas with a shallow snowpack, particularly on steep rocky slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1.5 - 3