Regions
Banff Yoho Kootenay.
Rising freezing levels should be expected over the next day or two. Keep in mind that rapidly warming conditions are detrimental to the snowpack and increase avalanche risk.
Weather Forecast
Rising freezing levels over the next two days (possibly to 2300m) will hold the danger rating at considerable. On Tuesday night the forecast could see up to 25cm of snow with warm temperatures and strong wind. This will elevate the danger rating to high on Wednesday.
Snowpack Summary
New wind slabs 15-25 cm thick in the immediate lees. Western areas such as Emerald and Field have a deep and stable snowpack. Contrast this with the Lake Louise, Hwy 93 N, & Sunshine areas, where there is a weaker snowpack with sudden collapse very easy compression results on the basal depth hoar. A crust exists on all but N aspects.
Avalanche Summary
No avalanches were observed or reported today.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Wednesday
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.
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.