Regions
Kootenay Boundary.
Winds switching from southwest to northwest have created wind slabs on a variety of aspects in the past few days.
Weather Forecast
TUESDAY: Mix of sun and cloud / Light west wind / Alpine temperature -5 C possible temperature inversionWEDNESDAY: Isolated flurries / Light southwest wind / Alpine temperature -5 C / Freezing level 500 mTHURSDAY: Flurries, accumulation 5-10 cm / Moderate southwest wind / Alpine temperature -3 C / Freezing level 1000 m
Avalanche Summary
Most recent reports from the weekend indicate widespread thin storm slab avalanche activity size 1-1.5 that were 15cm deep with a some avalanches running to size 2 where thicker wind deposits existed (up to 40 cm). These were reported as explosives triggered, naturally triggered and some skier controlled.
Snowpack Summary
20-40 cm of snow sits on a thin sun crust on southerly aspects and small feathery surface hoar in sheltered areas.Beneath this, around 50 to 100 cm of snow sits on a rain crust and a weak layer of feathery surface hoar and sugary facets. Although there has not been a reported avalanche on this layer in over a week, snowpack test results tell us that it is still possible to trigger. The lower snowpack is well-settled.
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.