Regions
Banff Yoho Kootenay.
We are on the verge of better ski quality given the current forecast. Watch locally for new wind slabs in the alpine sitting over harder surfaces beneath. SH
Weather Forecast
The Lake Louise region will start to see snow to the tune of 10cm on Friday with freezing levels to 2200m. The Banff/Sunshine region may only see 5cm. A storm pushing through the region for the weekend may bring 20-25cm along the divide with light to moderate westerly winds.
Snowpack Summary
Recent strong wind has created hard slabs on the snow surface in the alpine. 5-10cm of new snow fell on the Wapta today in the alpine. New snow Friday with wind will increase the wind slab thicknesses. At and below treeline expect to find a mix of facets and crusts. As ghastly as that combination sounds, generally it is well bonded.
Avalanche Summary
No new avalanche observations today.
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.
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.