Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
Forecasted new snow amounts Friday night and Saturday are variable. The more snow we receive, the more likely the hazard will increase to High.
The past week the snowpack has seen significant inputs with rain at lower elevations, warming and lots of new snow. Give the snowpack some time to recover before stepping out.
Confidence
Low
Avalanche Summary
No new avalanches were observed or reported Friday. A widespread avalanche cycle throughout the region occurred on Wednesday and Thursday. Avalanches to size 3.5 started at all elevations and ran mainly to the tops of runouts, with some going to valley bottom.
On Wednesday an avalanche on Quartz ridge was observed taking out previous ski tracks. A notable on Thursday was the ice climb Masseys in Field, running for a second time in 2 days to the valley bottom.
Snowpack Summary
5-20cm new snow overlies crusts from previous rain at treeline and below. Up to 50cm of settling snow has fallen over the past week forming 50-100 cm dense slab, that sits atop persistent weak layers of facets. In Eastern areas, facets and depth hoar extend to the ground, whereas, in thicker regions west of the divide, the layer is thinner with a more settled lower snowpack
Weather Summary
Friday night: Cloudy with scattered flurries. Accumulation: 5-10 cm. Alpine temperature: Low -7 °C. Ridge wind light to 20 km/h.
Saturday: Cloudy with scattered flurries. Accumulation: 5-15 cm. Alpine temps: High -3 °C. Ridge wind west: 10-25 km/h. Freezing level: 1700-2000m.
Sunday: Cloudy with sunny periods. Precipitation: Nil. Alpine temps: Low -9 °C, High -2 °C. Ridge wind 15 km/h. Freezing level: 2100m.
Terrain and Travel Advice
- Give the new snow several days to settle and stabilize before pushing into bigger terrain.
- Uncertainty is best managed through conservative terrain choices.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
Avalanche Problems
Persistent Slabs
A 50-100 cm slab of dense snow now sits atop mid-pack facets and, in eastern areas, depth hoar to the ground. There has been a lot of activity on this layer, and where it hasn't avalanched, it will be prone too.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3.5
Storm Slabs
10-25 cm of new snow is expected by Saturday evening, adding to previous slabs. It is uncertain how reactive these will be. Lower elevations may produce wet avalanches depending on freezing levels. Higher elevations may produce dry loose avalanches depending on upper level temperatures and wind
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2