Avalanche Forecast
Issued: Dec 9th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
TH,
Avalanche Canada
Use conservative terrain selection in any area displaying a slab of cohesive snow in the upper snowpack. This season's low snow inputs and cool temperatures have favored a weak lower snowpack.
Early season hazards remain poorly covered.
Summary
Confidence
Moderate
Avalanche Summary
A report of a few sz 1.5 slabs initiating in the alpine lees on Mt Dennis and scrubbing to the ground came in Friday afternoon. Lake Louise reported 14/15 shots producing results in untouched terrain, several of which were persistent slabs to sz 2. Sunshine village remote triggered some very soft slabs on the walls of the Canyon BTL.
Snowpack Summary
Snow inputs have continued for the past 4 days amounting to 10-40cm with up to 20cm last night at Sunshine. This, combined with previous moderate SW winds has formed wind slabs at higher elevations. These slabs have contributed the persistent slabs that sit on a weak base made up of facets, surface hoar and a crust. Average snowpack depths at treeline are 60 to 100 cm throughout the region.
Weather Summary
Following a brief ridge overnight with alpine temps -15to -20C , a frontal system off of the coast will push moderate SW winds carrying flurries into the area Saturday morning. Alpine temps -5 to -10C during the day and -10 to -15C overnight.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- Approach lee and cross-loaded slopes with caution.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Persistent Slabs
A 20-60 cm slab sits over a persistent weak layer of facets, crusts, and isolated pockets of surface hoar depending on location. Buried and recent wind slabs have been the main contributors to the formation of these slabs but generally: make conservative terrain selections in any areas holding consolidated snow in the upper snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
10-40 cm of snow has fallen over the past few days and has been blown into soft wind slabs by south and west winds. in some locations. These slabs are relatively soft and small but still possible to trigger.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 10th, 2022 4:00PM
