This persistent weakness will be with us for the rest of the season. Travel accordingly.
Weather Forecast
Cool temps, freezing level dropping and gusting SW-ly ridge top winds. Precip forecasted overnight (4-6cm in Icefields; trace amounts in Maligne) but to be perfectly honest, I'll believe it when I see it.
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
Previously noted size 2 slab avalanches on cross-loaded Alpine features, west aspect. Significant whining and moaning from travel partners once you step off the beaten track BTL in the Maligne valley, as well as whumphing and cracking.
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.