Avalanche Forecast
Issued: Dec 14th, 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 spooky buried weak layer lurks under the surface. Conservative decision making is key. Check out our latest blog for advice on how to manage this problem.
Summary
Confidence
Moderate
Avalanche Summary
Over the past week, we've had multiple reports of persistent slab avalanches on a buried weak layer. On the weekend, two skier-triggered size 2 avalanches were reported ~40 cm deep at treeline near Golden. Otherwise, persistent slab avalanches throughout the region have been mostly explosive controlled, size 1-2.
In the neighboring central Columbia and west Kootenay regions, where the weak layer is buried deeper, large avalanches on this layer have been prolific. Unfortunately, more likely than not, this is a sign of what is to come for the Purcells.
Snowpack Summary
5-10 cm of recent snow sits on a variety of surfaces ranging from hard wind slabs to soft, unconsolidated facets.
A concerning weak layer composed of surface hoar, facets and/or a crust that formed in mid November is now buried 15-40 cm deep. Avalanche activity has been observed on this layer and is expected to continue as the overlying snow takes on more slab character due to settlement, wind and additional snow load.
Alpine snowpack distribution is variable, with depths ranging from 40 to 140 cm.
Weather Summary
Wednesday night
Partly cloudy. Light northwest wind. Alpine low -15 C.
Thursday
Mostly sunny. Light northerly wind. Alpine high of -9 C.
Friday
A mix of sun and cloud. Ridgetop wind increasing to moderate northwest as a cold front passes through. Alpine high of -10 C.
Saturday
A mix of sun and cloud with isolated flurries. Light to moderate westerly wind. Alpine high of -12 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Problems
Persistent Slabs
A buried weak layer composed of surface hoar and facets is becoming increasingly problematic as it is buried deeper and overlying snow gains slab property. Avalanches are most likely to be triggered on this layer in areas around treeline.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Pockets of fresh wind slab may be found at ridetop. Aging wind slabs may remain reactive to human triggers, especially where they overlie a weak, sugary lower snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 15th, 2022 4:00PM
