Regions
Banff Yoho Kootenay.
Change will be coming to region on Saturday with the passage of a cold front. Winter conditions will prevail through Sunday.
Weather Forecast
Strong W winds with freezing levels near 2000m are expected through Friday. Saturday will see the passage of a cold front, bringing 10-30cm of snow, along with continued strong W/SW winds. Freezing levels should drop to 1800m with the passage of the front.
Snowpack Summary
Wind slabs can be found in steep alpine features, especially near ridge crests. These slabs can be triggered on all aspects, especially S where they overly harder crusts. A field team up the Storm valley encountered breakable crust to 2350m. They decided to save their legs for days where cooler overnight temp's establish a more supportive crust.
Avalanche Summary
A field team saw a sz 2 cornice triggered avalanche rumble from the ridge-crest near Storm Mountain today. It was likely triggered by a brief, intense sunny period, coupled with strong W winds. There was also evidence of a natural cycle from the last 24-36hrs from all aspects to 2800m in the Storm valley.
Confidence
Forecast snowfall amounts are uncertain
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.