Watch for local accumulations and building avalanche danger over the weekend.
Weather Forecast
Heavy snow fall warning in effect for Jasper. Mild temperatures and up to 20cms new snow are expected through Sunday.
Snowpack Summary
Additional mass added to the already weak snowpack will likely result in heightened avalanche danger this weekend. In the alpine storm and winds slabs are found and test with easy to moderate shears. Near treeline the midpack is supportive and untracked powder can be found in wind sheltered locations.
Avalanche Summary
Increased loading with new snow and wind forecast for the weekend will renew avalanche activity. Field teams noted debris of 2 sz 2.5 slab avalanches which had released in the last 48 hours on the basal facets at alpine elevations. Control work with large explosives produced avalanches to size 2 below on Thursday.
Confidence
Forecast snowfall amounts are uncertain
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.