Avalanche Forecast

Issued: Dec 12th, 2024 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs.

Avalanche Canada Avalanche Canada, Avalanche Canada

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Heightened avalanche conditions may exist where snow overlying a weak layer has settled into a cohesive slab.

Summary

Confidence

Moderate

Avalanche Summary

Since the weekend, natural, skier and explosive-triggered avalanches have been reported around the region. By Wednesday, most activity was explosive-controlled size 1-2, with a few naturals size 1-1.5. Slabs are 20 to 60 cm deep, predominantly in north to east alpine terrain, and in many cases, failing on a weak layer of 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

Thursday Night

Mostly cloudy with a trace of snow. 10 to 20 km/h south ridgetop wind. Treeline temperature -5 °C.

Friday

Cloudy with 1 to 5 cm of snow. 20 to 40 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.

Sunday

5 to 10 cm of snow then clearing midday. 20 to 40 km/h west ridgetop wind. Treeline temperature -7 °C. Freezing level 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Cautiously approach steep slopes that are open or sparsely treed.
  • Be aware of the potential for larger than expected storm slabs due to buried surface hoar.
  • Carefully evaluate steep lines for wind slabs.

Problems

Storm Slabs

An icon showing 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

Possible

Expected Size

1 - 2.5

Valid until: Dec 13th, 2024 4:00PM

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