Regions
Banff Yoho Kootenay.
The new snow has begun to improve ski conditions at treeline and above. Watch for wind slabs in specific terrain features and keep an eye on cornice development over the weekend. Travel remains a bit rugged at lower elevations.
Weather Forecast
Light snow and mild temperatures with moderate SW winds are forecast through Saturday. Sunday we expect a mix of sun and cloud with cooler temperatures. Monday and beyond look unsettled with occasional light precipitation.
Snowpack Summary
8cm of new snow at tree line and above on Friday with moderate SW winds and temperatures near 0`C. Wind slabs present in lee and open areas at tree line and above. The recent snow sits on a variety of surfaces and is generally bonding well. The base of the snowpack is made up of facets and depth hoar and remains weak. Below tree line snow is moist.
Avalanche Summary
Local ski areas were able to ski cut small wind slabs in immediate lees areas on Friday. This problem is expected to increase slightly over the next 36hrs as more snow arrives.
Confidence
Intensity of incoming weather systems is 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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.