Regions
Kootenay Boundary.
Variable snowfall amounts accumulated across the region. The snow may be reactive on Saturday, either as soft slabs or loose snow. The persistent slab problem still exists and is best controlled by diligent group management.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
FRIDAY NIGHT: Cloudy with isolated snowfall, accumulation 1 to 3 cm and locally higher amounts possible, light variable wind, alpine temperature -11 C.SATURDAY: Cloudy with isolated snowfall, trace accumulation, light variable wind, alpine temperature -10 C.SUNDAY: Clear skies, light northwest wind, alpine temperature -9 C, freezing level 1300 m.MONDAY: Clear skies with afternoon clouds, light to moderate southwest wind, alpine temperature -7 C, freezing level 1400 m.
Avalanche Summary
Numerous small (size 1) loose dry avalanches were observed in treeline and alpine terrain on Thursday, being triggered naturally and by skiers.
Snowpack Summary
Around 15 to 25 cm of recent snow overlies wind-affected snow in exposed terrain, soft and faceted snow in sheltered areas, and a melt-freeze crust on southerly aspects.Two layers of weak and feathery surface hoar crystals are buried in the snowpack between 40 and 80 cm deep, which were buried mid-February and early-February. The layers may be associated with a melt-freeze crust on southerly aspects. These layers remain reactive in snowpack tests and have produced sporadic avalanches in the region over the past week.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.