Regions
Kootenay Boundary.
You may be managing more than just the new snow. A reactive crust lies up to 70cm below the surface, and can produce surprisingly large avalanches.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
WEDNESDAY NIGHT: 5-10cm of snow / moderate southwest winds / freezing level at about 1800mTHURSDAY: 5-10cm of snow / moderate southwest winds / freezing level dropping from 1800m to 1500m throughout the dayFRIDAY: light snowfall with 10-15cm of new snow falling overnight / moderate southwest winds / freezing level at about 1200mSATURDAY: light flurries with a mix of sun and cloud / light northwest winds / freezing level at about 1000m
Avalanche Summary
Numerous size 1-2 natural, skier-controlled, and explosive controlled slab avalanches were reported on Monday and Tuesday. Some of these slabs failed on the buried crust mentioned in the Snowpack Discussion. These slabs were reported on all aspects, and were mainly on slopes above 1800-1900 m. Below 1800 m there have been ongoing reports of size 1-1.5 loose wet sluffs on steeper terrain.
Snowpack Summary
On Thursday expect new wind slabs to develop at treeline and in the alpine. Rain at lower elevations will continue to saturate the upper snowpack. 35-70 cm of recent storm snow sits on a supportive crust at and below treeline, a breakable crust on south-facing slopes in the alpine, buried surface hoar in sheltered terrain, or old wind affected surfaces. A few buried surface hoar layers exist in the top 100 cm in drier areas on the west side of the region. In other areas the notable early January surface hoar layer is 80-130 cm deep and poses a low probability/ high consequence threat. It should remain on your radar, especially in thin snowpack areas and during periods of significant warming or rapid loading.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.