Regions
Banff Yoho Kootenay.
A robust wind event with varying snow amounts will occur this weekend making for the possibility of natural avalanches at upper elevations. Watch locally for wind slab development. SH
Weather Forecast
Strong to extreme West winds Saturday (85-100+kmh) with incoming snow of 20-25 cm in the alpine along the divide. Much less snow is expected in the Banff region. Freezing levels to 1900m . Continued windy conditions Sunday with some light snow. Monday we will see a cooling trend.
Snowpack Summary
Very warm and windy conditions Friday with no overnight freeze up to 2500m. Variable wind slabs in alpine regions sit over a variety of harder surfaces and a generally well settled midpack.
Avalanche Summary
Limited observations Friday but no new avalanches reported.
Confidence
Forecast snowfall amounts are uncertain on Saturday
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.