Conservative decision making and disciplined terrain use is the name of the game when these tricky avalanche conditions persist. Check out the new Forecaster Blog @ avalanche.ca.
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
A weak system will slide down the coast and start to affect the Interior on Saturday bringing snowfall amounts 10-20cm. Ridgetop winds will be light-moderate from the west, switching to a northerly flow by Sunday. Alpine temperatures will hover around -15 then drop to -18 later Sunday. Conditions will remain cold and dry through Tuesday.
Avalanche Summary
Natural avalanche activity has tapered off and skier/ rider triggered avalanches are the name of the game. On Thursday several skier triggered avalanches size 1 were reported. These failed on the buried surface hoar layer 45 cm down on NE aspects in between 1400-1600 m.
Snowpack Summary
A cohesive slab (40-80 cm) sits above a touchy surface hoar layer that was buried mid-December. Below 2100 m this slab sits on a thick, solid crust/ surface hoar combination and has been acting as a perfect sliding layer. Persistent slabs will be very touchy to the weight of a skier and rider, especially in wind effected areas. A hard rain crust with facets from early November is buried over 1 m down and is currently unreactive, however; triggering from shallow rocky and unsupported terrain remains a concern.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.