Regions
Kootenay Boundary.
Confidence
Fair - Timing or intensity of solar radiation is uncertain on Tuesday
Weather Forecast
Monday night: No snow. Moderate NW winds. Alpine temperature near -12.Tuesday: No snow. Sunshine. Light to moderate SW winds. Alpine temperature near -9.Wednesday: Heavy snow (20- 35 cm). Strong to extreme SW winds. Alpine temperature near -3.Thursday: Light snow. Light SW winds. Alpine temperature near -10.
Avalanche Summary
Numerous size 1-2 avalanches were triggered naturally, by skiers, explosives and vehicles on Sunday. In most cases, the new snow was failing on the hard crust below. Many were soft slabs where the wind had shifted the snow onto lee slopes, and several were loose dry avalanches.
Snowpack Summary
Around 20-30 cm of recent storm snow overlies a hard refrozen crust in most places. Strong variable winds have shifted this new snow into touchy wind slabs in the lee of terrain breaks. In non-wind affected steep terrain, sluffs are running easily.Deeper in the snowpack, weak surface hoar/crust interfaces have become much less likely to be triggered now that they are capped by a supportive rain crust. However, I’d remain wary of any spots where the crust above is not as strong.
Problems
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.
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.
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.