Avalanche Forecast
Issued: Dec 13th, 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.
ahanna,
Avalanche Canada
A buried weak layer has produced large rider-triggered avalanches in recent days. Keep your terrain choices conservative and be prepared to back off quickly if you find signs of instability like whumpfing, shooting cracks and recent avalanches.
Read our featured blog to learn more about how to manage a persistent slab problem when traveling in the backcountry.
Summary
Confidence
Avalanche Summary
On Sunday, several large (size 2-3) persistent slab avalanches were reported. They were remotely triggered by skiers or snowmobiles at treeline elevations. Check out these MIN reports here and here. A huge thank you to the groups who shared their observations to the Mountain Information Network!
Since then, avalanche observations have been limited to small explosive-triggered wind slabs.
Snowpack Summary
A thin sun crust may be found on south aspects, while surface hoar grows at treeline and below. 30-50 cm of recent snow has been redistributed by previous winds at upper elevations. This recent snow may overlie surface hoar in wind sheltered areas.
A concerning weak layer consisting of facets and surface hoar formed in November is now buried 80-90 cm deep. At the bottom of the snowpack, a thick crust sits on the ground.
At treeline, snowpack depths vary from 120 to 200 cm.
Weather Summary
Tuesday night
Flurries bringing 3-8 cm. Light northeast wind. Alpine low -9 C.
Wednesday
Flurries in the morning bringing 4-8 cm then clearing. Light northeast wind. Alpine high -6 C.
Thursday
Mix of sun and cloud. Light northerly wind. Alpine high -9 C.
Friday
Mix of sun and cloud. Wind increasing to strong northwest. Alpine high -12 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be especially cautious as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- The trees are not the safe-haven they normally are at this time. Terrain at treeline is primed for human triggered avalanches.
Problems
Persistent Slabs
Buried layers of surface hoar and facets have been reactive to human triggers in recent days at treeline elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Wind slabs may remain triggerable by riders. Wind loaded slopes at treeline should be treated with extra caution.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 14th, 2022 4:00PM
