Regions
Banff Yoho Kootenay.
A storm Thursday night into Friday will likely increase the wind slab problem at upper elevations. Watch locally for snow amounts and how the wind is transporting it. Ridge tops and gully terrain will be likely areas to find new wind slabs. SH
Weather Forecast
A vigorous low is approaching the divide. 24 hour snow quantities should see 10-25cm, with lesser amounts in Eastern areas. This will be accompanied by a cold front. Expect moderate to strong SW winds at upper elevations, easing in the afternoon.
Snowpack Summary
15-30 cm of snow sits on top of a supportive (5-10cm) crust except on high N which overlies a strong base. The bond to the crust seems strong in most places. Winds over the day have changed the surface in many areas and new wind slabs are starting to form in alpine lee areas.
Avalanche Summary
A few size 1-1.5 avalanches were noted in the quartz ridge area of the Sunshine back country, otherwise no new were reported.
Confidence
Intensity of incoming weather systems is uncertain on Friday
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.