Regions
Banff Yoho Kootenay.
Avalanche activity has settled down slightly with the cooler temperatures, and the ski quality is good - dry snow on a supportive crust right down into the trees. We remain concerned about human triggering and are avoiding avalanche starting areas.
Weather Forecast
A strong SW flow over the mountains will create favorable conditions for heavy snow along Hwy 93N Icefields Parkway. Snow will continue Tuesday evening over the higher elevations and end near midnight. 10-20cm is possible by Wednesday morning. The heaviest snowfall will be from Sask River Crossing to the southern sections of the Jasper region.
Snowpack Summary
Another 10-15cm of new snow overnight on Tues brings to the 5-day dry storm snow amount to 40cm. Moderate winds have been transporting this snow, but windslab formation has been limited in the past 24 hours. The main weakness to watch is the Oct 31 crust/facet layer located about 30cm above the ground which produces easy, planar shear test results.
Avalanche Summary
No avalanches were reported or observed today, but visibility was limited.
Confidence
Wind effect is extremely variable
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.