Regions
Kootenay Boundary.
Watch out for fresh slab development above the rain-snow line on Saturday from new snow and strong southwest wind. The snow may be wet and loose at lower elevations and on south aspects, particularly if the sun shines.
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
FRIDAY NIGHT: Cloudy with snowfall, accumulation 10 to 15 cm, moderate to strong southwest wind, alpine temperature -2 C, freezing level 1700 m.SATURDAY: Mix of sun and cloud with isolated snowfall, accumulation trace to 5 cm, moderate to strong southwest wind, alpine temperature -4 C, freezing level 1500 m.SUNDAY: Cloudy with snowfall, accumulation 10 to 15 cm, moderate to strong southwest wind, alpine temperature -2 C, freezing level 1700 m.MONDAY: Cloudy with snowfall, accumulation 5 to 15 cm, light northwest wind, alpine temperature -1 C, freezing level 1800 m.
Avalanche Summary
Numerous wind slabs and loose wet avalanches were observed on Thursday. They were reactive to skiers, explosives, and loose wet avalanches occurred naturally during daytime warming. They were all within the recent storm snow.
Snowpack Summary
Around 10 to 20 cm of snow is forecast for Saturday above 1500 m, which will overly a melt-freeze crust or wet snow. The snow will fall with strong south wind, producing wind slabs in lee terrain features. Below 1500 m, the snowpack is wet and rapidly melting.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.