Avalanche Forecast

Issued: Dec 27th, 2022 3:00PM

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

Avalanche Canada Dvonk, Avalanche Canada

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Recent wind and warm temps have formed wind slabs at Treeline and above. These slabs sit on a particularly weak base this winter, which will be extremely slow to improve. Backcountry users need to adopt a conservative mindset and make cautious terrain decisions for the foreseeable future.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches observed or reported today.

Snowpack Summary

Up to 5cm of fresh snow overlies a new rain crust formed yesterday up to at least 2200m. The upper snowpack has gained some density with the warm temps. Wind slabs are present in Alpine and exposed Treeline terrain, particularly just below ridgelines and in gully features. Below this new snow and wind slabs the snowpack is very weak. Forecasters are tracking the Dec 16th surface hoar/facet layer down 10 to 20cm and the mid-November facet/surface hoar/depth hoar layer down 50 to 80cm. If avalanches are initiated on these layers they will likely step to ground through the very weak basal facets/depth hoar. It's not a pretty picture!

Weather Summary

Light flurries overnight with more of the same through Wednesday. Accumulations will likely be around 5cm. Mild temps and moderate SW winds are forecasted, with a cooling trend later in the week.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
  • Be especially cautious as you transition into wind affected terrain.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

This layer should be monitored as elevation is gained. Despite being labelled as deep, it can be a ways off the ground. Entrainment is a major concern. These avalanches could run to valley bottom.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

Continuing SW winds and warmer temps will continue the growth of wind slabs. If triggered the wind slab is very likely to steep down to the deeper instability.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 28th, 2022 4:00PM