Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Very little change is occurring to the avalanche conditions right now. This week's dominant theme is the wind effect at higher elevations and the very occasional triggering of a windslab. When temperatures are this cold, the snowpack does not change much - but continuous winds will scour the surface and deposit isolated windslabs.
Confidence
High
Avalanche Summary
No new avalanches were observed or reported on Wednesday.
On Tuesday, we investigated the Quartz skier accidental avalanche, where the start zone was 48° and the failure plane was an old layer of weak facets down 50 cm. The avalanche was triggered from a very shallow, faceted location and the crack propagated into the thicker snowpack nearby and released the avalanche. This is a classic avalanche release pattern.
Snowpack Summary
Last week's storm snow has been redistributed into wind slabs, which now sit on top of the Jan 30 interface. The mid-pack is generally weak with facets, while depth hoar over a crust forms an even weaker base. The snowpack is the weakest in eastern areas where snow depths are low. In these areas, the basal weaknesses should be carefully considered. Here is a representative snow profile taken on Wednesday at Sunshine Village.
Weather Summary
The Arctic ridge of high pressure continues to dominate the region and we can expect mostly clear skies (a few clouds), very cold temperatures (highs -15, lows -25), no new snow and light winds from the north. This pattern shows no sign of breaking down until a slight change on the weekend.
Terrain and Travel Advice
- Be careful as you transition into wind-affected terrain.
- Closely monitor how the new snow is bonding to the old surface.
- Be mindful that deep instabilities are still present in the snowpack.
Avalanche Problems
Wind Slabs
Lingering hard wind slabs exist on alpine lee features. Potential failure planes are old weak facet layers or the Jan 30 layer of facets, sun crusts, and isolated surface hoar beneath the recent snow.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2