Regions
Banff Yoho Kootenay.
Great ski quality to be had right now. Just remember that there are still weak basal facets deep in the snowpack, and it is a slow start to spring. Ease into bigger terrain and avoid slopes under large cornices.
Weather Forecast
Snow tapering off in all regions for Friday with light winds and freezing levels down to valley bottom overnight and up to 1900m with mainly cloudy skies. A cooling trend is expected through the weekend.
Snowpack Summary
Small amounts of snow this past week have added up to about 20-40cm. On solar aspects, this new snow is sitting over a couple of sun crusts into the alpine, and small storm slabs 20cm thick have formed in specific alpine features. At tree line and above a 120cm+ firm slab with few weaknesses overlies weaker basal facets in much of the region.
Avalanche Summary
No new avalanches observed or reported on Thursday.
Confidence
Due to the number of field observations
Problems
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
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.