Regions
Northwest Inland.
Wind slabs are more reactive in locations West of Hankin-Evelyn and the Telkwa due to higher snowfall amounts and stronger ridgetop winds.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
Friday: Mix of sun and cloud with a trace of new snow. Ridgetop winds light from the South and alpine temperatures near -9.Saturday: Mostly cloudy with isolated flurries. Ridgetop winds light from the SE and alpine temperatures -10. Sunday: Cloudy with sunny periods and an alpine high of -12.
Avalanche Summary
On Wednesday, numerous natural storm slabs up to size 1.5 were reported from the western part of the region and no avalanche activity reported from the Telkwa riding locations. Isolated wind slabs may be found in alpine locations on leeward slopes.
Snowpack Summary
Recent low density storm snow up to 25 cm has fallen with surprisingly little wind effect. The new snow has buried a variety of old snow surfaces including stiff wind slabs, facets, crusts and surface hoar. The new snow may have a poor bond to these interfaces. At treeline elevations the average snowpack depths are 120-190 cm and a well consolidated mid-pack of approximately up to 100 cm sits above weak basal facets (sugary snow) near the ground. Recent snowpack testing has shown sudden easy results down 25 cm on a surface hoar layer and sudden hard results down 100 cm within the facetted snow. The deeper basal weakness remain a concern, especially from thin rocky start zones and shallower snowpack locations.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.