Avalanche Forecast
Issued: Dec 26th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
JSmith,
Avalanche Canada
Lingering wind slabs may still be reactive to human triggers. A buried weak layer at treeline and below continues to be a concern. This problem can be avoided through conservative terrain choices.
Summary
Confidence
Weather Forecast
SATURDAY NIGHT: Snow; 3-5 cm. / Light, southwest ridgetop wind / alpine low temperature -8 / Freezing level valley bottom.
SUNDAY: Cloudy with isolated flurries; 0-3 cm. / Light, southwest ridgetop wind / alpine high temperature -8 / Freezing level valley bottom.
MONDAY: Cloudy / Moderate, northwest ridgetop wind / alpine high temperature -9 / Freezing level valley bottom.
TUESDAY: Mix of sun and cloud / Moderate, northwest ridgetop wind / alpine high temperature -11 / Freezing level valley bottom.
Avalanche Summary
On Monday there was a report of a human triggered avalanche that was suspected to have run on buried surface hoar. The MIN report can be view here.
Data in this region is very sparse. Please submit your observations to the Mountain Information Network.
Snowpack Summary
Winds blowing from a variety of directions have redistributed new snow from last week and built wind slabs in lee features at treeline and above.
An active weak layer is now down 40 to 70 cm. The distribution of this layer is variable. In some areas it's surface hoar and/or a crust; in others this layer may be difficult to find if it exists at all. Recent human triggered avalanches have been reported on this layer and have been most numerous in the areas between Blue River and Valemount.
There is a prominent crust near the base of the snowpack. This crust likely has weak facets above and/or below it. There have been no recent avalanches reported on this layer, but would be most likely to trigger in steep, shallow, rocky terrain, with a thin to thick snowpack.
Terrain and Travel
- Be careful as you transition into wind affected terrain.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Wind Slabs
Moderate winds shifting in direction have created wind slabs in the lee of terrain features on a variety of aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A slab rests on a persistent weak layer which has the capacity to propagate avalanches across terrain features. Although the likelihood of triggering a persistent slab avalanche is reducing, the potential for triggering a high consequence avalanche should still be top of mind in your decision making process.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 27th, 2020 4:00PM
