Avalanche Forecast

Issued: Dec 1st, 2022 4:00PM

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

Avalanche Canada AL, Avalanche Canada

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The cold temperatures will continue to persist through Saturday, be prepared to stay warm in an emergency. Many early-season hazards are still lurking just below the surface.

Summary

Confidence

Moderate

Avalanche Summary

Sunshine Ski patrol reported a few small size 1 slab avalanches that release from a steep treeline feature outside of the ski area boundary.

A fracture line profile was done Thursday on a skier-triggered avalanche in the Lake Louise backcountry. See MIN report

Snowpack Summary

20-40cm of recent snow redistributed by upper elevation winds has now settled into a slab overlying a weak layer of facets, surface hoar, or sun crust on steep south aspects. 40-80 cm of total snow exists at treeline throughout the region, with up to 120 cm in loaded alpine features.

Weather Summary

The surface ridge will persist over the Rockies, however, an upper disturbance passing to the southwest of Alberta will continue to bring cloud and scattered flurries to the Rockies. Expect higher snowfall amounts on the West slopes of the Rockies, with up to 5cm of accumulation in the Little Yoho area. Winds are expected to increase through the day Friday.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • If triggered, loose dry avalanches may step down to deeper layers resulting in large avalanches.
  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Recent snow and wind loading has created slabs over a persistent weak layer of facets, buried sun crusts, or isolated pockets of surface hoar. This slab has been sensitive to natural and human triggering.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Loose Dry

An icon showing Loose Dry

This is a forecasted problem due to the faceting of the upper snowpack and increased winds expected Friday afternoon. With such a weak upper snowpack, wind transport can easily initiate dry loose avalanche activity in extreme terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 1.5

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

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