Regions
Kootenay Boundary.
Weather Forecast
Synopsis: Generally very fine weather with cool overnight temperatures and warm, sunny days.Sunday, Monday and Tuesday: Clear and sunny. Freezing level around 1600 m, becoming slightly higher each day. Light winds.
Avalanche Summary
On Friday, only small sluffs were observed. On Thursday, several size 1.5-2 avalanches were either deliberately ski-cut or accidentally triggered on a range of aspects at elevations from 1800 - 2100 m. All failures were on a crust, typically buried 20-40 cm deep. Explosive avalanche control produced similar results.
Snowpack Summary
Between 20 and 60 cm recent storm snow rests on a thick crust that exists up to ridge top. The bond between the storm snow and the crust was initially poor above 1800 m, but appears to have gained some strength. In some places, you may find an additional, thinner crust within the top 60 cm snow. A buried surface hoar layer lies buried approximately 80 cm below the surface and continues to fail in a sudden planar fashion when tested. However, in most places it is likely not a concern due to the thick supportive crust that lies above it. Potentially large fragile cornices loom over many slopes.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
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.