Avalanche Forecast

Issued: Dec 23rd, 2024 4:00PM

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

Avalanche Canada Avalanche Canada, Avalanche Canada

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Carefully assess steep slopes, as small surface avalanches could trigger deeper weak layers.

Summary

Confidence

Moderate

Avalanche Summary

Numerous avalanches were reported over the weekend, with a common theme across the region being wind slabs up to size 2, triggered by natural causes, skiers, and explosives. They primarily occurred in steep, alpine terrain on a variety of aspects, with depths up to 60 cm.

One explosive-triggered size 2.5 avalanche was reported in the north of the region. It failed on a buried weak layer, producing a crown up to 100 cm deep. This occurred in very steep, rocky, alpine terrain.

Snowpack Summary

20 to 40 cm of recent snow continues to settle and bond to underlying surfaces. Recent southwest winds have redistributed this snow into deeper deposits 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. The only location where this basal layer has shown signs of instability is in the Invermere area.

Weather Summary

Monday Night

Partly cloudy. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Tuesday

Partly cloudy with 2 to 8 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Wednesday

Mix of sun and cloud with 0 to 2 cm of snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -7 °C.

Thursday

Mostly cloudy with 0 to 2 cm of snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -7 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be careful as you transition into wind-affected terrain.
  • Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent snow has been redistributed by southwest wind into deeper deposits and reactive wind slabs at higher elevations.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

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 the Invermere area, weak facets and a crust at the base of the snowpack remain a concern.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Valid until: Dec 24th, 2024 4:00PM

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