Avalanche Forecast
Issued: Dec 12th, 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.
CG,
Avalanche Canada
The recent low-density storm snow is settling out and showing increasing signs of slab properties. There is uncertainty of if/when the tipping point will be reached on the persistent weak layers, which would likely result in the wide propagating avalanches seen adjacent to Rogers Pass.
Assess the snowpack carefully before stepping out into committing terrain.
Summary
Confidence
Moderate
Avalanche Summary
Several loose dry avalanches up to size 2 from steep, rocky North facing terrain off Mt MacDonald.
Reports continue of small, unsupported pockets of soft slab failing on Dec 5 and Nov 17, mainly occurring around treeline and morainal features.
Snowpack Summary
Up to 40cm of settled snow now buries the Dec 5 layer, which consists of surface hoar, preserved stellars, facets, and a thin sun crust on steeper solar aspects.
The Nov 17th Surface Hoar is now buried 60-90cm and continues to produce sudden results in snowpack tests.
Weather Summary
A ridge of high pressure will maintain dry conditions over the region for the next few days. Light winds, Alpine highs in the -5*C to -9*C, and no snow for the week.
Terrain and Travel Advice
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Persistent Slabs
The Nov 17 and Dec 5 surface hoar are down ~75cm and ~35cm respectively, and most prevalent around tree line. These layers of surface hoar give 'sudden' results in snowpack tests; they have a propensity to propagate across continuous and broken features; and, they produce dramatic whumpfs in previously untraveled open glades.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Wind Slabs
45cm of recent low density snow is available for transport. Isolated pockets of surface slabs may be found in Alpine and open Treeline lee features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 13th, 2022 4:00PM
