Avalanche Forecast
Issued: Dec 3rd, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
wlewis,
Avalanche Canada
Investigate the effect of the recent strong winds on the snowpack. Expect pockets of dense wind slab around ridgelines and mid slope terrain features.
Small avalanches have the potential to trigger deeper weak layers. Assess conditions as you travel and gain information
Summary
Confidence
Avalanche Summary
Early season observations are limited! We expect natural and rider triggered wind slab avalanches to also have occurred throughout this region, from available snow and strong winds. Explosives produced size 1.5 wind slabs on Thursday.
A layer of surface hoar layer continues to be a concern. Avalanches up to size 2 were last reported on this layer on November 29th, believed to fail on the surface hoar before 'stepping down' to weak and sugary facets near the base of the snowpack. Check out this MIN report for more details.
We have very few eyes out there. If you do get out please consider reporting in the MIN.
Snowpack Summary
Strong southwest winds will have redistributed recent snowfall into dense wind slabs at upper elevations. In exposed terrain some slopes may have been stripped back to early season layers or rock. In sheltered terrain new wind affected snow sits above more faceted (sugary, weak) snow which may not bond well. Cold temperatures have weakened and faceted the snowpack as a whole. A rain crust sits near the ground.
Total snowpack depths at treeline elevations are 50-80 cm and in the alpine 70-140 cm. In many areas, below treeline elevations remain below the threshold for avalanches.
Weather Summary
Saturday Night
Mostly clear skies with cold temperatures. Winds ease to moderate from the west/northwest. No snowfall expected.
Sunday
Clear skies to start with some cloud developing over the day brings a possibility of isolate flurries. Winds are expected to stay light to moderate from the south. Alpine high of -10.
MondayCloudy with light snowfall expected over the day bringing up to 3 cm. Strong westerly winds return. Alpine high -10.
TuesdayA similar story, cloudy with up to 5 cm and strong westerly winds at ridgeline. Alpine high -15.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Choose low-angled, sheltered terrain where new snow hasn't been wind-affected.
Problems
Wind Slabs
Strong southwest winds has likely formed dense wind slabs on north and easterly facing slopes. Avoid snow that feels drum like or hollow. In exposed areas extreme winds may strip the slopes - making for poor travel and riding conditions.
Small avalanches may trigger a bigger avalanche by 'stepping down' to the weak and faceted crystals buried deeper within the snowpack.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Buried layers of surface hoar and facets have been reportedly been reactive in nearby areas. This layer is widespread throughout the Rockies. It will be most reactive where the snow above these layers acts as a slab (as opposed to loose snow) such as wind loaded areas.
Observations on this layer are currently limited. In times of uncertainty such as this, the best defence is to keep terrain choices conservative and reduce your exposure to avalanche terrain where possible.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 4th, 2022 4:00PM
