Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
Snow and wind is forecast over the next few days. Expect a small increase in the avalanche danger until the weather calms down again.
Confidence
Moderate
Avalanche Summary
Forecasters investigated a size 2 skiier remote avalanche from yesterday in the Wild West area at Sunshine Village. This failed 65 cm down on one of the January PWLs.
Otherwise, Lake Louise ski hill reported triggering a few small windslabs in alpine terrain and Sunshine snow safety team observed a size 1.5 naturally triggered windslab out of north facing alpine terrain.
Snowpack Summary
Wind slabs are present in the alpine and at treeline. These wind slabs overlie the various Jan PWL interfaces of sun crusts, facets, and surface hoar down 80-120 cm. The weaker Nov 16 basal facet layer is down 100-200 cm, and produces moderate to hard sudden collapse results. Deeper snowpack areas west of the divide are stronger and more supportive than areas to the east.
Weather Summary
A system is moving in from the Alaskan Gulf on Thursday, followed by convective flurries for Friday, tapering Saturday. We should see ~ 2 cm by Thursday AM.
Thursday: ~ 5 cm. Alpine winds strong from the SW. Treeline temperatures -5 to -10.
Friday: ~ 5 cm. Alpine winds moderate from the W. Treeline temperatures -8 to -10.
Saturday: Light south alpine winds. Low near -20 in the AM. Light flurries in the afternoon.
Terrain and Travel Advice
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Wind Slabs
Wind slabs from last weeks storm are becoming more stubborn, but incoming snow and winds will build new ones over the next few days. Remain vigilant in lee areas where wind slabs are more likely.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Persistent Slabs
Three persistent weak layers formed in January are down 70-100 cm. The biggest concern is triggering these buried suncrusts on steep solar slopes, but weaker facets and isolated surface hoar can be found on the same interface on shaded aspects.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5
Deep Persistent Slabs
Weak facets and depth hoar are present at the bottom of the snowpack. Incoming snow and winds over the next few days will increase load on our fragile snowpack. Be especially cautious in thin snowpack areas, which are likely areas for triggering.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 3