Regions
Banff Yoho Kootenay.
The long cold snap has left a weak snowpack that is not healing. Conservative route selection will be required into the foreseeable future.
Weather Forecast
Moderately cold weather with sun and flurries is forecast. While this is great for touring, it is unlikely to strengthen our weak snowpack in the short term.
Snowpack Summary
The snowpack is quite localized. 10-40 cm of storm snow (often windslab) rests on weak facets. Deeper layers of weak facets and depth hoar are common. A supportive midpack can be found, but it is often friable and may contribute to deeper failures. avalanches were reported today butLower elevations have unsupportive bottomless facets.
Avalanche Summary
Several size 2 avalanches were reported in the Banff area today. Recent reports of human involvement would indicate the need for continued caution.
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.