Regions
Banff Yoho Kootenay.
Watch for windslabs in alpine lee areas and loose dry avalanches in steep terrain. Ski quality is currently excellent.
Weather Forecast
A slight increase in cloud and wind (up to moderate west) is expected for Tuesday and Wednesday. Some light flurries forecasted on Tuesday with 1-2cm of accumulation. Temperatures will stay civilized for the next few days with day time highs to -5. Overall, minimal weather inputs that will impact the danger rating.
Snowpack Summary
30 to 50 cm of snow has fallen since Feb 2. This has been affected by variable winds, isolated periods of solar radiation and most notably, sustained cold temperatures promoting faceting. Down 30 to 75cm, Jan 17 surface hoar produces sudden planar shears in isolated locations treeline an below. A weak basal snowpack exists in shallow areas.
Avalanche Summary
Several reports of both skier triggered wind slabs and loose dry avalanches have been noted this past week. Generally these avalanches have been small (size1-2) but have been running far, entraining the loose faceted surface snow.
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.