Avalanche Forecast
Issued: Dec 18th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
rgoddard,
Avalanche Canada
Buried weak layers remain reactive to triggering.
Signs of instability like whumpfing and shooting cracks are a clear indication to back off and go with your 'Plan B.'
Summary
Confidence
Low
Avalanche Summary
No new avalanches reported in the last 24 hours. This was not the case earlier this past week. The mid-November surface hoar layer was very reactive throughout our region and in the rest of the Selkirks and Monashees. This layer will likely remain rider triggerable in specific sheltered terrain features.
Snowpack Summary
From Saturday night to Monday morning, 15 to 30 cm will have fallen throughout our region. This has buried a surface hoar layer that can be found on sheltered slopes and a sun crust on south-facing terrain. A small layer of surface hoar from early December can be found down 35 to 60 cm in sheltered and shaded terrain. On south-facing slopes, this layer is a thin crust. At this writing, neither of these layers has shown reactivity but that is likely to change with the addition of a slab on top of this layer.
A weak layer of large surface hoar crystals, facets, and a melt-freeze crust from mid-November sit 50 to 80 cm deep. This layer has been reactive at treeline between 1700 to 2200 m, on all aspects producing large remotely triggered avalanches.
Below the mid-November layer is a generally weak, faceted snowpack. Snowpack depths average 80 to 160 cm in the alpine.
Weather Summary
Sunday Night
Cloudy, 2 to 5 cm accumulation, 10 to 20 km/h west wind, -20 C at 1500 m.
Monday
Sunny, no accumulation, 15 km/h northwest winds, alpine temperature of -25 C.
Tuesday
Cloudy with sunny breaks, up to 5 cm accumulation, 15 km/h southeast wind, temperature -20 C at 1500 m.
Wednesday
Sunny, trace accumulation, 20 km/h northeast winds, alpine temperature of -25 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Don't let the desire for deep powder pull you into high consequence terrain.
- If triggered, loose dry avalanches may step down to deeper layers resulting in large avalanches.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Persistent Slabs
There are now two persistent weak layers within the snowpack.
A 35 - 45 cm soft slab sits above a weak layer of surface hoar on shaded aspects and crust on steep solar aspects.
A second weak layer of surface hoar and facets from mid-November is buried down 50 to 80cm in the region.
While avalanche activity has tapered off on these layers they likely remain rider triggerable in specific sheltered terrain features at treeline and below.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
Low density snow continues to accumulate on a wide variety of surfaces where bonding is not likely to occur. Moderate wind that is to accompany this new snow is likely to redistribute this snow and create fresh wind slabs.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 19th, 2022 4:00PM
