Avalanche control along the Icefields Parkway on Sunday produced results up to size 3. The new will require some time to stabilize, choose simple terrain that is well supported. Be vigilant if the sun comes out where it can wake up the new snow.
Weather Forecast
Tuesday and Wednesday will be -12 to -16, 25km/hr SW to S winds, and flurries. Thursday and Friday will be a deep freeze down to -24 with light East winds.
Snowpack Summary
45cm of storm snow from Friday and Saturday arrived with light and some moderate southerly winds. It continues to settle into a soft slab at treeline and above. The mid and lower snowpack is structurally weak, the base of which is 5mm depth hoar crystals and a deteriorating rain crust.
Avalanche Summary
Avalanche control work on Sunday produced up to sz 3, some stepping down to deep persistent layers or to the ground where weak facets and depth hoar exist. Natural activity was most prevalent in the alpine and similar to the control work, was stepping down, resulting in deep releases, sz 2-3. Sun came out today resulting in some natural activity.
Problems
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.