Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Jasper.
Use caution in crossloaded features. A windslab might step down to deeper weaknesses.
Weather Forecast
Wednesday will be cloudy with sunny periods and isolated flurries. Treeline high temperature of -5C, with light NW winds. Thursday-Friday: Temperatures stay steady around -5, with cloudy skies and flurries. Winds will be light to moderate from the SW A detailed mountain weather forecast is available from Avalanche Canada.
Snowpack Summary
5-10cm of snowfall on Sunday with SW - NW winds created wind slabs in lee and cross-loaded terrain. Surfaces became moist on solar slopes at treeline Monday. A layer of weak surface hoar is now buried 10-15cm deep. Below, a strong mid-pack sits over depth-hoar in the lower third of the snowpack (giving sudden results in snowpack testing Saturday).
Avalanche Summary
A natural Size 3 Deep Persistent slab was observed Monday on a steep (35+ degrees) Alpine South-West facing slope. Triggered by a smaller windslab, it stepped down to depth hoar and the ground. Several windslabs to Size 2 were also observed (Alpine S and E aspects). Help forecast - share observations HERE, on the Mountain Information Network!
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Friday
Problems
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.
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.