Regions
Banff Yoho Kootenay.
Control work today confirm touchy windslabs remain in the alpine and treeline - this layer will need some time to settle and bond with the underlying facets.
Weather Forecast
Relatively warm winter temperatures, a little more snow and continued westerly winds are forecast for the area. This should be good news in the long term, but it is expected that the new snow or windslab/facet interface will take a while to bond.
Snowpack Summary
The storm has brought us 15 to 30 cm of new snow, with more falling on the West side of the Divide. Moderate to strong winds have created a windslab that overlays a very loose faceted snowpack. The windslab/facet interface was touchy in avalanche control work on Tuesday. The Nov crust is 30-80cm deep, and is not currently reactive.
Avalanche Summary
Size 2 to 3 slab avalanches observed today running far for their mass. The most impressive results on Mt. Bosworth with long propagations & one slope failed when the explosive bag hit the slope. The failure layer are the windslabs on the facets. Not many naturals reported or seen, except for a size 2 over Pilsner climb area on Mt Dennis.
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.