The snowpack has doubled in a short period of time. This has overloaded a variety of weaknesses and created very dangerous avalanche conditions. The Icefields Parkway has reopened for the time being, check road report before making any travel plans.
Weather Forecast
More snow, up to 10-15cm and extremely high winds are expected in the forecast area over night in through tomorrow.
Snowpack Summary
35 to 50cm of storm snow has been redistributed by moderate SW winds creating wind slab over a strong mid-pack in lee features on top of a weak basal facets layer at the ground.
Avalanche Summary
Control work in the Icefields area produced significant results up to size 2.5. Most slides running in the storm snow but many results continue to scour the ground running on basal facets and burying the road. Of note, in one case, multiple slides were recorded from one shot remotely triggering up to 100m away and over running the road.
Confidence
Intensity of incoming weather systems is uncertain
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.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.