Regions
Banff Yoho Kootenay.
Excellent ski travel continues with the cooler temperatures. Monitor slopes for local wind slab formation and how they are bonding to the harder surfaces below. SH
Weather Forecast
Freezing levels to valley bottom overnight and up to 1900m for Friday with very little snow. Winds will stay in the light range and will switch to Westerly on Friday. Some snow is currently in the forecast for Saturday (up to 10cm).
Snowpack Summary
Below treeline the snow pack is a melt-freeze crust.10-20 cm of new snow in the alpine is forming wind slabs on E and N aspects.The midpack above treeline is well settled and overlies a weak facetted base. These basal facets have not been reactive recently, but should still be considered when making terrain choices, especially in thin rocky areas.
Avalanche Summary
A size 2 on a steep (40+ degree) moraine feature was triggered yesterday by a party exiting from Peyto hut with no involvement. The slide was approximately 100m wide and was the site of recent wind loading. The slide stepped to ground showing that the basal facets are mainly dormant, but features like these are still possible to initiate.
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.