Fresh storm slabs will become increasingly sensitive to human triggers as the snow load increases.
Summary
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Saturday night: 15-20 cm new snow/ Moderate to strong, southwest winds/ Freezing level 800 m.Sunday: 0-5 cm new snow/ Light, southwest winds/ Freezing level 800 m.Sunday night: 15-20 cm new snow / Light to moderate southwest winds / Freezing levels dropping to valley bottoms.Monday: 20-25 cm new snow/ Light, southwest winds/ Freezing level valley bottom.Tuesday: 0-5 cm new snow/ Light, southwest winds/ Freezing level valley bottom.
Avalanche Summary
No new avalanche observations were reported on Friday. Fresh storm slabs will likely have a poor bond to the old snow surfaces and be reactive through the weekend, potentially stepping down and initiating deep persistent slabs.
Snowpack Summary
20-25 cm of new snow has buried a variety of old snow surfaces including stiff wind slab or wind effected snow at upper elevations, sun crust on steep southerly slopes and surface hoar in sheltered areas. Another 15-20 cm is expected by Sunday morning bringing storm totals to 35-45 cm. Below the surface, 50-65 cm of settled snow now sits above an interface that was buried in mid-January. The interface is composed of weak facets, surface hoar, and/or sun crusts and the strength of the bond is reportedly variable. Recent snowpack tests have shown sudden results on that interface. Areas with a shallower snowpack (less than 150 cm) have a generally weak snowpack structure with sugary facets near the ground. This includes shallow alpine slopes and most of the Rossland range. Smaller storm slab avalanches may step-down to these deeper weak layers, resulting in large, destructive avalanches.
jsmith,
Avalanche Canada
