Avalanche Forecast

Issued: Nov 28th, 2022 4:00PM

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

Avalanche Canada CJ, Avalanche Canada

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Natural avalanche activity has tapered off, but the potential for human triggered avalanches remains, with lots of uncertainty around the likelihood of triggering slabs sitting over the weak basal facets. Treat steep terrain with extra caution.

The cold temperatures pose another hazard so dress warm and be prepared to stay out longer than expected.

Summary

Confidence

Moderate

Avalanche Summary

One size 2 skier triggered avalanche on the basal facets was observed near Lake Louise Monday afternoon. A couple size 2-2+ Na avalanches that failed during the recent storm were also observed on the 93N. They also appear to have failed on the basal facets.

Snowpack Summary

Over the past three days, up to 20 cm of storm snow has accumulated at treeline. The storm snow arrived with strong SW/W winds creating fresh wind slabs in the alpine and open treeline locations.

The snowpack below this recent snow is a mix of weak facets, spotty 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

Temperatures stay cold with alpine highs of -20°C as an arctic ridge settles into the region. Alpine winds remain light from the W/SW on Tuesday. Skies will become cloudy with trace amounts of new snow expected as an upper trough moves through the area.

https://www.avalanche.ca/weather/forecast

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Likelihood

Possible - Likely

Expected Size

1 - 2

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 and can result in full depth avalanches. This problem will likely get more difficult to trigger in the next week, but will remain with us for some time.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1 - 1.5

Up to 20 cm of storm snow distributed by strong SW/W winds has created new wind slabs. The wind slabs are getting harder to trigger, but approach wind loaded terrain carefully. If triggered these slabs could step down to the basal facet layers and result in a larger than expected avalanche.

Aspects:

North, North East, East, South East, North West.

Elevations:

Alpine, Treeline.

Valid until: Nov 29th, 2022 4:00PM

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