Lots of recent wind has redistributed snow in exposed areas and has likely set up wind slabs that could be reactive to the weight of a rider.
Summary
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
SATURDAY NIGHT: 5-10 cm additional new snow expected. Strong southwesterly winds.SUNDAY: Light snow, 2-4 cm. Moderate northwesterly winds. Treeline temperatures around -6C.MONDAY: Dry with sunny breaks. Light northerly winds. Treeline temperatures around -14C.TUESDAY: Dry with sunny breaks. Light southwesterly winds. Treeline temperatures around -15C.
Avalanche Summary
On Thursday and Friday, the South Rockies field team found weak faceted snow, saw shooting cracks and experienced whumpfing as they traveled around the Nordstrom area south of Elkford and around the Crowsnest Pass.A great MIN report from Corbin on Thursday identifies a few slabs initiating in thin, rocky areas on a south aspect. While this is in the Lizard Range and Flathead forecast region, similar conditions should be expected around the South Rockies. Check out the report
here.
Snowpack Summary
The upper snowpack consists of hard wind slabs on north aspects, scoured and a shallower snowpack on south aspects, and a mixed bag of lower density snow in more sheltered areas. In total, 60-90 cm of December snow has formed a slab that sits on a persistent weak layer of facets (sugary snow) that formed during the dry weather in early December. This layer is most likely to be triggered on steep features where the underlying ground cover is smooth, areas where the snowpack depths are variable, or on large convex features.The lower snowpack has a weak structure composed primarily of facets over a crust on the ground. It is very likely that an avalanche triggered on the persistent slab would step down to the lower facets, resulting in a full depth avalanche.
jfloyer,
Avalanche Canada
