Avalanche forecast

Purcells

Dec 27 – 28, 2024Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Rocky, wind-affected areas are a prime suspect for large, human-triggered avalanches.

Seek out sheltered, moderate-angled slopes for the best and safest riding.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Fresh, reactive wind slabs exist in lee and cross-loaded areas from yesterday's snowfall and wind.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    In the mid-snowpack, buried surface hoar or facets may pose a risk on north-facing slopes, while a buried sun crust could be reactive in south-facing areas.

    In shallow snowpack areas, facets at the base of the snowpack are generally weak.

Confidence

Moderate

Avalanche Summary

On Tuesday, a large skier-triggered avalanche (see this MIN) indicated reactive wind slabs failing on facets are a significant issue in alpine and treeline terrain.

On Wednesday, explosive control near Invermere produced numerous size 1 deep persistent slabs from steep, treeline terrain.

Both of these avalanche problems will continue into Friday. Steep, rocky, wind-loaded areas are prime suspects for either of these dangerous instabilities!

Snowpack Summary

5 to 20 cm of new snow has fallen in the past 24 hours. Accompanying southwest winds have likely redistributed this new snow, forming deeper deposits on leeward slopes at higher elevations.

A layer buried in early December is found roughly 20 to 90 cm below the surface. This layer varies, consisting of weak surface hoar or facetted crystals on shaded slopes and a sun crust with facets on south-facing slopes.

The base of the snowpack is made up of a thick crust and facets in many areas.

Weather Summary

Thursday Night

Cloudy with up to 5 cm of new snow. 15 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Friday

A mix of sun and cloud with up to 3 cm of new snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -6 °C.

Saturday

Cloudy with up to 10 cm of new snow. 25 to 50 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Sunday

Mostly cloudy with up to 2 cm of new snow. 10 to 30 km/h southwest switching to northeast ridgetop wind. Treeline temperature -5 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid freshly wind-loaded features, especially near ridge crests, rollovers, and in steep terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Regions covered