Avalanche Forecast
Regions: Banff Yoho Kootenay.
Lots of good skiing in sheltered areas. Remember to consider the persistent layers if venturing into bigger terrain.
Weather Forecast
A relatively benign period of weather through Thursday with mixed sun and cloud, no precip, and freezing levels near valley bottoms. Winds are NW in moderate range.
Snowpack Summary
Wind effect and wind slabs in the alpine and exposed tree-line areas. New suncrusts steep solar. 20 to 40 cm of recent snow lies over a facet interface formed in late December. The Dec2 crust and facets are generally 60-100cm deep and continue to produce results in snowpack tests. Some thin snowpack areas have lingering basal depth hoar and facets.
Avalanche Summary
A size three cornice triggered avalanche was observed on the east face of Carnarvon (above Hamilton Lakes in Yoho Park). This stepped down to a deeper persistent layer, which illustrates that big triggers or "hitting the sweet spot" can still produce large avalanches.
Confidence
Wind speed and direction is uncertain on Friday
Avalanche Problems
Wind Slabs
Recent winds have created windslabs in the alpine and some treeline locations. These slabs are now 3-4 days old and we expect their sensitivity to decrease however they may be more reactive where they overly facets.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2
Persistent Slabs
This problem represents both the Dec. 2nd crust/ facet layer (treeline and below) and layers of faceted snow that were formed during the late December cold snap (all elevations). If triggered, either layer could result in large avalanches.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Forecasters are operating with alot of uncertainty at this time.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3