Regions
Banff Yoho Kootenay.
If the storm arrives as forecasted, avalanche danger will rise on Wednesday. Be cautious of overhead hazard as natural avalanche activity is likely from steep alpine terrain.
Weather Forecast
A system is approaching on Wednesday and is forecasted to bring 10-20 cms with M-S SW alpine winds and freezing levels to 1800m. On Thursday, the storm eases with only a few cms. cooling temps, and easing winds. Friday is looking relatively clear, with cool temps and light winds.
Snowpack Summary
Cold temperatures have tightened the snowpack, creating a supportive crust at lower elevations. In the alpine and at treeline, convective storms have dropped 10 - 30 cm of new snow which sits on top of suncrusts on solar aspects and old facetted snow on polar aspects. In some areas, windslabs may exist, although the winds have been mostly light.
Avalanche Summary
A field team in the White Pyramid area on the 93N remote triggered a small, thin windslab of little consequence in the alpine today. Reports indicate increased winds were causing numerous loose dry avalanches out of steep alpine terrain.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Wednesday
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.