Regions
Banff Yoho Kootenay.
Although forecasted amounts of snow are minimal, act accordingly if more snow than expected is encountered.
Weather Forecast
A system has built into the forecast region which will bring light amounts of precip amounting to about 10cm over the next 36 hours. Wind will remain light from the SE. Temperatures will be cooler than seasonal with valley bottom just above 0 and 3000m temps hovering around -10.
Snowpack Summary
Small amounts of snow over the weekend have added up to about 20-40cm. This new snow is generally bonding well with some isolated pockets of wind slab in the alpine. Below tree line the surface snow is moist on solar aspects. 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 Wednesday.
Confidence
Intensity of incoming weather systems is uncertain on Thursday
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.