Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Rossland, St. Mary, Valhalla, Ymir.
Keep decision making conservative as weak layers remain a concern.
Choose smaller, low angle slopes free from overhead hazard.
Confidence
Moderate
Avalanche Summary
Explosive control work continued on Thursday, producing numerous avalanches up to size 4 (very large). While natural activity appears to have tapered off now, human triggering is still a concern.
A notable size 3.5 avalanche was remote-triggered from a ridgeline in the Bonningtons on Tuesday, see the photo below.
And check out this photo blog of recent avalanches throughout the province.
Snowpack Summary
Surface conditions include settling storm snow, sun crusts on south facing slopes, and lightly wind-affected snow at higher elevations.
A widespread crust is buried 100-150 cm deep with a layer of weak facets above (and/or surface hoar in isolated sheltered terrain). This continues to be the layer of concern throughout this region, as it continues to produce very large avalanches throughout this region.
The snow below the crust is generally strong and well bonded.
Weather Summary
Friday Night
Partly cloudy. 10-30 km/h southwest ridgetop wind. Freezing level drops to valley bottom.
Saturday
Mostly cloudy with up to 5 cm of snow in the afternoon for the Monashees and Selkirks and a mix of sun and cloud in the Purcells. 30-50 km/h southwest ridgetop wind. Freezing levels rise to 1600 m, with treeline temperatures around -2 °C.
Sunday
Cloudy with 5 to 15 cm of snow. 20-40 km/h south ridgetop wind. Freezing levels rise to 1500 m, with treeline temperatures around -3 °C.
Monday
Cloudy with 5 cm of snow. 20-30 km/h southwest ridgetop wind. Freezing levels rise to 1500 m, with treeline temperatures around -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
Avalanche Problems
Persistent Slabs
While this layer is becoming less likely to be affected by a rider, if triggered, a large and destructive avalanche is certain. Avoid areas where the snowpack thins, like steep, rocky start zones. Weak layers are more easily triggered here
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 2 - 3.5
Wind Slabs
Winds have picked up and loose snow is available to build fresh and reactive wind slabs.
Small wind slabs could step down to deeper weak layers producing very large avalanches.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2