Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
We are still wary of most steep terrain in the backcountry. Every day this week we've seen avalanche activity on the weak layers deep in the snowpack. Choosing moderate angled terrain with limited overhead hazard remains the best way to manage this snowpack.
Polar aspects should hold better skiing than sun exposed features at treeline and below.
Confidence
Moderate
Avalanche Summary
While natural activity has tapered off, we are still getting large whumpfs, and occasional natural and skier triggered avalanches on the deeper weak layers in the snowpack. A cornice triggered size 3 avalanche reported by Mt. Norquay ski hill in the last 48 hrs is the most recent.
Snowpack Summary
A sun crust is present on steep solar slopes at treeline and below, with 10-30 cm of soft snow on northerly aspects. The various Jan PWL interfaces of sun crusts, facets, and surface hoar are now down 40-80 cm. The weaker Nov. 16 basal facet layer is down 120-170 cm and still produces whumpfing and moderate to hard sudden collapse results in tests.
Weather Summary
A few cm's of new snow is expected Friday night with scattered flurries and a few sunny breaks on Saturday. Light W-SW winds with cool alpine temperatures of between -15 to -20°C are forecast.
For a more detailed weather forecast, click here.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Avalanche Problems
Deep Persistent Slabs
Weak facets and depth hoar are present at the bottom of the snowpack and inspire little confidence. Tests continue to show sudden collapse characteristics with whumpfs observed when travelling. Be especially cautious in thin snowpack or rocky areas, which are likely areas for triggering. Recent natural cornice failures have also triggered this layer, so consider your overhead hazard while travelling.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1.5 - 3.5
Persistent Slabs
Three persistent weak layers formed in January are down 40-80 cm. The biggest concern is triggering these buried suncrusts on steep solar slopes, but weaker facets and isolated surface hoar can be found at the same interfaces on shaded aspects. A few avalanches on these layers have been observed in the past week.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5