Regions
Banff Yoho Kootenay.
Sunshine and cool temps are making for good travel conditions. Good skiing can be found on sheltered North aspects. Stay alert to the potential for triggering the basal weaknesses in thin snowpack areas! CJ
Weather Forecast
Generally sunny conditions with alpine temperatures between -15 and -7'C and light NW-W winds for Monday and Tuesday. Wednesday is forecast to have some light precipitation in the forecast.
Snowpack Summary
A few cm of new snow overnight over the Jan 25th surface hoar and sun crust layer which sits on a supportive mid pack. In thicker snowpack areas the basal facets are gaining strength and no significant shears have been found. In thinner snowpack areas the basal facets are still quite weak and producing moderate sudden collapse results in tests.
Avalanche Summary
No new avalanches observed in the past several days. Cooler temperatures are minimizing the solar triggered sluffing. The potential still exists for full depth avalanches on the basal facets in specific terrain features.
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.