Avalanche forecast

Purcells

Dec 5 – 6, 2024Avalanche Canada
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Avalanche danger

Sat
Sun
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

Wind slabs may be reactive in leeward terrain features at higher elevations.

Lingering concern remains for a weak layer near the base of the snowpack which may still be reactive in some areas.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Lingering concerns remain for wind slabs in leeward features resulting from recent westerly winds.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2

    Avalanches on weak faceted snow at the base of the snowpack are becoming less likely, but remain possible on steep, smooth slopes.

Terrain and Travel Advice

  • Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
  • Be mindful that deep instabilities are still present in the snowpack.
  • Triggering deep layers is more likely if the snow surface didn't freeze overnight.

Confidence

Low

Avalanche Summary

On Tuesday, small loose avalanches were reported on steep south aspects.

Last week, several small (size 1 to 1.5) deep persistent slab avalanches were reported in the Invermere area. These 40 cm thick slabs were failing on weak basal snow and have been triggered by both riders and explosives.

Snowpack Summary

Treeline snow depths are generally 50 to 70 cm, with deeper wind-loaded pockets in the alpine. New surface hoar is growing on the surface in sheltered terrain and wind-affected surfaces are expected in exposed terrain at higher elevations. A new sun crust is likely forming on steep, sun-exposed slopes.

In the Invermere area, weak faceted snow at the base of the snowpack has caused several small but notable deep persistent slab avalanches.

Early-season hazards are present at all elevations. Stay alert and assess terrain carefully.

Weather Summary

Wednesday Night

Mainly clear. 10 to 20 km/h southwest ridgetop wind. Treeline temperature near 0 °C with a temperature inversion.

Thursday

Mainly sunny. 10 to 20 km/h southwest ridgetop wind. Treeline temperature near 0 °C with the temperature inversion breaking down through the day.

Friday

A mix of sun and cloud. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -3 °C.

Saturday

Cloudy with snowfall up to 15 cm. 30 to 60 km/h southwest ridgetop wind. Treeline temperature -3 °C.

More details can be found in the Mountain Weather Forecast.

Regions covered