Regions
Banff Yoho Kootenay.
Continued load on the weak base will have the potential to wake up the weak base on slopes that have not yet avalanched. We are in a period of slowly rising avalanche danger. JBW
Weather Forecast
A series of pacific storms in a westerly flow will bring precipitation to the west sides of the divide and warm westerly winds to the east. The strongest in the series looks to be Friday night into Saturday and may be enough to bump the avalanche danger rating higher.
Snowpack Summary
Some light wind transport and a trace of new snow today with the first in a series of storms in a strong westerly flow. Last weeks storm snow is settling, but the weak base of depth hoar and/or crust is still the major concern.
Avalanche Summary
The natural avalanche activity triggered by last weeks storm has subsided and no new avalanches have been observed in the last 36 hrs. The potential for triggering still remains likely.
Confidence
Intensity of incoming weather systems is uncertain on Saturday
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.