Avalanche Forecast
Issued: Dec 19th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
Parks Canada,
Avalanche Canada
A significant storm brought 40cms of new snow and strong winds, which is a perfect recipe for slab development.
Cautious route-finding and conservative decision-making is essential
Summary
Confidence
Moderate
Avalanche Summary
Avalanche control at Rogers Pass on Wednesday produced storm slab avalanches to size 3.
Several natural avalanches were observed in the highway corridor during the last storm. Naturals ran up to size 3 with some running running full feature.
Snowpack Summary
40cm of new snow has fallen with strong gusting Southerly winds. This lands on variable wind slabs already present in the Alpine and at Treeline. A persistent weak layer is down 50-70cm. This interface consists of surface hoar in sheltered locations, a sun crust on solar aspects, and continues to produce moderate-hard sudden results in test profiles. The snowpack's base is comprised of several early-season melt-freeze rain crusts.
Weather Summary
A pacific frontal system approaches BC and brings light snow to the Selkirks.
Tonight: 11cm, Alp low -4°C, Mod-Strong SW wind, Freezing level (FZL) 1500m
Fri: Trace precip, Alp High -1°C, Strong SW wind, FZL 1800m
Sat: 4cm. Alp High 0°C, Strong SW winds, FZL 1900m
Sun: Trace precip, Alp high -4°C, Moderate SW wind, FZL 1500m.
Terrain and Travel Advice
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
Problems
Storm Slabs
In the last 24-48 hours there has been 30-50cms of new snow, accompanied by strong/extreme S & West winds. A reactive, cohesive storm slab will form with these conditions and will be easily triggered by riders.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
60-80cm of snow overlays a layer of surface hoar in sheltered zones, and a sun crust on steep, solar aspects. There has been limited activity on this layer in recent days, but the new load from the incoming storm could re-awaken this problem.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 20th, 2024 4:00PM
