Avalanche Forecast

Issued: Dec 1st, 2022 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Watch for new and reactive wind slabs forming as winds strengthen over the day.

Assess conditions as you climb in elevation, and use caution around ridgelines and wind-loaded features.

Summary

Confidence

Low

Avalanche Summary

On November 29, two natural storm slab avalanches up to size 2 were reported. These are suspected to have failed on a buried surface hoar layer that sits 15-30 cm below the surface before 'stepping down' to weak and sugary facets near the base of the snowpack.

With this new snow and strong winds forecast, natural and rider-triggered avalanches activity may continue.

We have very few eyes out there. If you do get out please consider reporting in the MIN,

Snowpack Summary

Upper Snowpack: 15-30 cm of recent snowfall combined with strong southwest wind have formed fresh storm slabs at upper elevations. The new snow sits above harder, wind-affected snow in exposed terrain features and in sheltered areas above more faceted (sugary, weak) snow which may not bond well.

Lower Snowpack: Cold temperatures have weakened and faceted the snowpack. A rain crust sits near the ground.

Total snowpack depths at treeline elevations are 50-80 cm and in the alpine 70-140 cm. Below treeline elevations remain below the threshold for avalanches.

Weather Summary

Thursday Night

Skies clear and temperatures drop overnight. Trace accumulations of snow possible near Crowsnest Pass. Winds remain moderate from the West.

Friday

Mainly sunny skies with cloud developing in the afternoon. Scattered snow is possible with trace accumulations expected. Daytime highs of up to -12 expected in the alpine. Winds increase over the day to strong from the southwest.

Saturday

Some cloud and possible scattered flurries expected to clear in the afternoon. Winds remain strong from the southwest, becoming extreme near the Crownest Pass. Wind speeds drop significantly over the evening. -10 alpine high.

Sunday

Clearing skies with light and variable winds that are expected to shift to light easterlies late afternoon, bringing a possibility of light snowfall late in the day.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
  • Recent new snow may be hiding windslabs that were easily visible before the snow fell.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent fresh snow combined with strong west/southwest winds will form reactive wind slabs on north and easterly facing slopes. If triggered, small avalanches may result in a bigger avalanche by 'stepping down' and triggering the weak and faceted crystals buried deeper within the snowpack.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 2nd, 2022 4:00PM

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