Avalanche Forecast
Regions: Banff Yoho Kootenay.
As temperatures cool and the winds back off Monday, we expect the hazard to do the same.
Be aware that it is still heads-up hockey out there with both lingering windslabs and the persistent slab problem producing recent avalanches.
Weather Forecast
As a trough moves south through Alberta Monday, most of the region will see patchy cloud and light flurries as temperatures cool a few degrees. Winds are expected to shift north and back to light to moderate speeds. The winds look to rebound Tuesday as do the temperatures which may reach -5C in the alpine.
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
Avalanche control in Kootenay and on the Sunshine road Friday produced several results to size 2 at alpine and tree line elevations. The predominant weak layer triggered, were surface winds slabs 20-40cm deep. This past week we have observed several large avalanches failing on the persistent avalanche problem.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Tuesday
Avalanche Problems
Wind Slabs
Recent winds have created wind-slabs in the alpine and some tree-line locations. These slabs are now 3-4 days old and we expect their sensitivity to decrease however they may be found over facets in some locations and remain sensitive.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: 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 will result 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