Don't be fooled by the lack of natural activity. The weakness around the buried persistent slab is still lurking in the snowpack and is most likely triggered in Portal/Whistler Creek and Maligne Lake Areas.
Weather Forecast
Clear and freezing level rising to over 2000 m on Saturday then an intense but short storm Saturday night with heavy snow, falling freezing level and strong South winds dropping up to 10 cm. Temperatures remain cool on Sunday and snow with light winds on Monday.
Snowpack Summary
Maligne/Jasper: Variable snow depth above tree-line, relative to exposure. Average HS 70cm. Surface wind slabs and persistent slab down 40-90cm. Icefields: Variable snow depth above tree-line, relative to exposure. Average HS 120cm. Widespread wind slabs overlaying supportive mid pack and weak base.
Avalanche Summary
Field team in the Icefields noted a few size 2 slab avalanches on cross-loaded Alpine features, west aspect. Whumphing and cracking noted below tree line around Bald Hills. Marmot reported little in the way of natural activity around the ski hill today except a cornice initiated slab on Sherpa.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Saturday
Problems
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.
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.