Regions
Banff Yoho Kootenay.
The period of uncertainty continues as touchy conditions persist. Be judicious when making terrain choices.
Weather Forecast
A benign weather pattern is settling into the forecast region. Mild temperatures, light wind and zero snow accumulations are expected over the next 3 days. As such, the danger rating will not change.
Snowpack Summary
Wind slabs are present in many open areas above tree line. Below this, the snow pack is quite weak and facetted in most places. The Dec 18 crust/facet interface is down 30-40cm at tree line. Backcountry users are experiencing widespread of whumphing on this layer. The bottom half of the snow pack consists of facets and depth hoar.
Avalanche Summary
No avalanches observed or reported today. However, conditions are still touchy.
Confidence
The weather pattern is stable on Monday
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.