Regions
Banff Yoho Kootenay.
Watch for fresh windslabs in lee and cross-loaded terrain in the alpine and at treeline. Even a small avalanche in exposed terrain could have high consequences. Overall, a great start to the season in the Rockies, though!
Weather Forecast
An arctic high pressure system has moved in and we are under the influence of N/ NE flow for the foreseeable future. This means cold temps (highs -5 to -10 and lows of -15 to -20 in the valley bottoms), with clear skies and generally light N/ NE winds. Expect some moderate gusts which will make those temperatures feel cold!
Snowpack Summary
5-15 cm of storm snow from Monday overnight overlies widespread wind effected terrain above treeline, and a soft well settled snowpack below treeline. The new snow is being blown into fresh windslabs in isolated leeward and crossloaded areas at treeline and in the alpine, typically 10-30 cm thick and they may trigger easily.
Avalanche Summary
Sunshine and Lake Louise ski hills were reporting fresh windslabs reactive to ski cuts in alpine and treeline terrain today. These were generally small, and 10- 30 cm deep in lee and crossloaded terrain.
Confidence
The weather pattern is stable
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.