Regions
Kootenay Boundary.
If the riding is good, the snowpack stability might not be.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Mainly cloudy with around 5 cm of fresh snow on Thursday, 10 cm on Friday and another couple expected on Saturday. Freezing levels are expected to gradually rise from valley bottom on Thursday to 1600 m or higher by Saturday afternoon. Winds should remain light but gusty from the south.
Avalanche Summary
There we no new reports of avalanches on Tuesday and Wednesday morning.
Snowpack Summary
Light flurries are burying large surface hoar sitting on or near a thick hard supportive rain crust that extends as high as 2100 m. Critical slopes are high elevation north aspects where facets or buried surface hoar from earlier in the month may be lurking under dense storm slabs, and older facet/crust weaknesses may be persisting. Recent snowpack tests at 2050 m in a NW aspect in Kootenay Pass produced moderate sudden results down 35 cm under the late-November crust and down 79 cm on facets above the early-November crust. Meanwhile in the Southern Purcells, snowpack tests last weekend gave easy sudden planer results on well preserved surface hoar where it was found down 30 cm on high north aspects.
Problems
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
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.