Avalanche Forecast
Regions: Bonnington, Grohman, Kootenay Boundary, Kootenay Pass, Norns, Rossland, Ymir.
A calm weather day marks the end of the year.
Surface instabilities and deeper weak layers may remain reactive to riders.
Choose low-consequence terrain and watch for signs of instability.
Confidence
Moderate
Avalanche Summary
On Sunday, skiers were surprised by the storm snow at treeline and alpine on northerly slopes, with several avalanches (size 1.5 to 2) in the Bonnington Range and around Whitewater Resort.
Evidence of a natural avalanche cycle was also reported over the weekend throughout the region.
If you head out in the backcountry, let us know what you are seeing by submitting a MIN report!
Snowpack Summary
30 to 50 cm of settling snow can be found in sheltered areas. Previous moderate southwest wind has redistributed this snow, forming deeper deposits on leeward slopes at higher elevations.
Below this recent snow, a thin crust is present below approximately 1600 m.
Weak layers of surface hoar or facets and a crust may persist in the mid-snowpack. Professionals are still concerned about its potential instability.
The lower snowpack is generally strong and well-bonded.
Weather Summary
Monday Night
Mostly cloudy, with isolated flurries. 10 to 20 km/h northwest ridgetop wind. Treeline temperature -8 °C.
Tuesday
Mostly cloudy, with isolated flurries. 10 to 20 km/h souhtwest ridgetop wind. Treeline temperature -8 °C.
Wednesday
Cloudy with up to 5 cm of new snow. 10 to 20 km/h souhtwest ridgetop wind. Treeline temperature -10 °C.
Thursday
Mostly cloudy, with isolated flurries. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -10 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices.
- Keep in mind that human triggering may persist as natural avalanches taper off.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- Pay attention to the wind; once it starts to blow, sensitive wind slabs are likely to form.
Avalanche Problems
Persistent Slabs
Buried weak layers of surface hoar and facets on a crust are now buried 70 to 120 cm deep. Increased load from new snow may make these layers more reactive. Be especially cautious on steep, open slopes at treeline and below.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2.5
Storm Slabs
Recent snowfall and wind have formed storm slabs in lee and cross-loaded areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5