Avalanche Forecast
Issued: Dec 11th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
Avalanche Canada,
Avalanche Canada
As the upper snowpack continues to settle, cohesive slabs may form. In areas where these slabs overlie a weak layer, they may be easily triggered by riders.
Summary
Confidence
Moderate
Avalanche Summary
Since the weekend, natural, skier and explosive-triggered avalanches continue to be reported around the region. Most are size 1 to 2, with some explosive results up to 2.5. Slabs are 20 to 60 cm deep, predominantly in north to east alpine terrain, and in many cases, failing on weak surface hoar crystals.
Although conditions are improving, it remains possible that riders could trigger similar avalanches going forward.
Snowpack Summary
Around 30 to 50 cm of snow accumulated last weekend and it has remained relatively cool and cloudy since then. The snow may remain soft without slab properties in some locations, but as the snow settles it may form a slab. This is particularly problematic where the snow may rest on weak surface hoar crystals in openings below treeline, at treeline elevations, and at lower alpine elevations. Otherwise, it rests on a hard melt-freeze crust on sun-exposed slopes and on all aspects at low elevations.
In exposed alpine terrain, westerly wind may have formed small wind slabs in lee terrain features.
The remainder of the snowpack is strong without any deeper concerns at this time.
Weather Summary
Wednesday Night
Partly cloudy. <15 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Thursday
A mix of sun and cloud. 10 to 20 km/h south ridgetop wind. Treeline temperature -6 °C.
Friday
Cloudy with 2 to 5 cm of snow. 10 to 30 km/h south ridgetop wind. Treeline temperature -6 °C.
Saturday
Cloudy with 5 to 15 cm of snow. 50 to 60 km/h south ridgetop wind. Treeline temperature -4 °C. Freezing level rising to 1300 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Keep your guard up as storm slabs may remain sensitive to human triggering.
- Cautiously approach steep slopes that are open or sparsely treed.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
- Be aware of the potential for remote triggering and large avalanches due to buried surface hoar.
- Carefully evaluate steep lines for wind slabs.
Problems
Storm Slabs
As last weekend's storm snow settles, it may form a slab that could be triggered by riders. This is predominantly a problem where the snow overlies weak surface hoar crystals. Use caution in steep openings sheltered from the wind.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 12th, 2024 4:00PM
