Regions
Banff Yoho Kootenay.
Watch for the bond between wind slabs and loose powder to harder bed surfaces below before stepping into steep alpine terrain features.
Weather Forecast
Clouds will slowly move into the area, along with increasing winds from the W/NW. We may see light amounts of snow later in the day, but no real accumulations until Friday/Saturday. Freezing levels should hold around 2000m for Thursday/Friday.
Snowpack Summary
Cool temp's and thin high cloud kept crusts intact today into the afternoon. 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. Loose snow avalanches on N aspects over harder bed surfaces in the alpine were seen Tuesday.
Avalanche Summary
A field team saw heavy sloughing with ski cutting in a steep North aspect (2800m) in the Lake O'Hara region. This was overlying a harder bed surface. Numerous other avalanches to size 1.5 have been observed in steeper terrain, especially on Southerly aspects.
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.