Regions
Banff Yoho Kootenay.
Light snow accumulations expected over the next 48 hours. Danger rating will rise to considerable in the alpine. Remain vigilant when making terrain choices.
Weather Forecast
Up to 20cm in the next 48 hours at high elevations may just be enough new snow load to tip the scale and increase the avalanche danger to considerable (in the alpine). Expect temperatures to rise to approximately -10 with moderate NW wind as the system approaches the forecast region.
Snowpack Summary
80-120cm exists across the region. The main weakness is the basal facets and depth hoar. Compression test results were moderate in the Stanley Valley today. The Dec18 surface hoar is down ~20cm, but does not currently have enough snow load above it to be of concern. In the alpine, thin windslabs can be found in isolated, wind exposed areas.
Avalanche Summary
No new avalanches were observed or reported today.
Confidence
Intensity of incoming weather systems is uncertain on Monday
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.