Great skiing continues during a break in snowfall. We have broken out this forecast region due to the deeper snowpack and lower likelihood of triggering the deep persistent layer.
We have limited recent alpine observations.
Moderate to strong NW-SW winds have moved recent snow, creating wind slabs in alpine and open treeline terrain. There is also more wind in the forecast on Wednesday, which is keeping the likelihood raised. Watch for these as you transition into wind-affected terrain.
The natural avalanche cycle on this layer has ended. Be wary of shallow areas, as this has been where the bulk of recent large avalanches have started, going from thin to thick.
New natural wind slabs up to size 1.5 were observed today in the Kootenay. Ski hills reported mixed results from explosive control, with generally fewer and smaller avalanches than expected. However, Lake Louise patrol triggered a size 3 deep persistent slab that failed to ground. This fits the recent trend: low overall reactivity, but the potential remains for large, destructive avalanches in isolated areas.
Strong winds have continued to develop windslabs in alpine and open treeline terrain. In sheltered areas, recent storm snow (20-30 cm) remains preserved.
There is 40-80 cm over the Dec 15 melt-freeze crust (which is present to 1800-2000 m), 80-160 cm over the November facet/crust interfaces, and, in thinner snowpack areas, facets at the base.
Treeline snow depths range from 100-200+ cm.
A weak ridge of high pressure will remain in place through Thursday, bringing a mix of sun and cloud, moderate ridge-top winds, and freezing levels near valley bottom. Precipitation is expected to begin Friday, with forecast accumulations of 5–10 cm by Saturday.
