Regions
Kootenay Boundary.
Confidence
Fair - Timing or intensity of solar radiation is uncertain
Weather Forecast
Wednesday night and Thursday: An upper ridge persists on the region bringing dry conditions, moderate to strong winds from the Western quadrant and an inversion with temperatures above the freezing level between 2000 m. and 2500 m. Friday: Traces of snow are forecasted with moderate winds from the NW and dropping freezing levels to 600 m. Saturday: Similar conditions are expected with lighter winds from the S and slightly warmer temperatures (around -4 C in the alpine).
Avalanche Summary
Small loose dry avalanches have been reported in steep terrain and also loose moist avalanches on steep solar aspects.
Snowpack Summary
Forecasted alpine warming and direct sun may lead to a loose moist snow surface. New wind slabs were formed by recent NW winds below ridgetops on lee aspects. Loose dry snow is sluffing in sheltered terrain. A generally settled upper snowpack overlies the late November surface hoar, buried down 115-130 cm. This layer seems particularly reactive in the Rossland Range, in rocky, thin snowpack areas. A deeply buried crust/facet layer near the base of the snowpack is considered dormant. Although unlikely, there is a lingering possibility of triggering a persistent slab in isolated areas.
Problems
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.
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.