Regions
Kootenay Boundary.
Watch for blowing snow at ridgetops to see where wind slabs are developing.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
FRIDAY: Isolated flurries, 20-40 km/h southwest winds, alpine temperatures at -15.SATURDAY: Light flurries with up to 5 cm accumulations, 20-40 km/h southwest winds, alpine temperatures at -12.SUNDAY: Isolated flurries, 20-40 km/h west winds, alpine temperatures at -12.
Avalanche Summary
Small loose dry avalanches continue to be reported in steep terrain, but no slab avalanches have been reported since Tuesday.
Snowpack Summary
Northerly winds continue to redistributed loose snow, forming stubborn wind slabs in exposed alpine areas. New surface hoar up to 15 mm in size has been reported growing on the surface, and will continue to develop during this fair weather period. The top 25 cm of snow remains low density thanks to cold temperatures, and sits above a thin rain crust in parts of the region. The lower snowpack has been reported to be well settled. A widespread crust that was buried in November can be found 40-80 cm deep. Cold temperatures have promoted facet growth around the crust, which could make the layer reactive in shallow start zones. Snowpack depths are 130-160 cm at treeline elevations.
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.