Avalanche Forecast

Moderate - Due to the number of field observations

Seasonal temperatures and isolated flurries through the weekend. Significant alpine warming Tuesday afternoon. SUNDAY: Cloudy / Light - moderate southwesterly winds / Freezing level around 900 m. MONDAY: Sunny with cloudy periods, warming with highs to +1Celsius / Moderate southeasterly winds / Freezing level around 1200 m. TUESDAY: Mostly cloudy / High temperatures to +3 Celsius / Light-moderate southwesterly winds/ Freezing level near 2000m.

Near Nelson, several persistent slab avalanches to Size 3 (average depths ranging from 60cm to 100cm) were triggered on virtually all aspects above 1900m with explosives on Saturday. See Whitewater Ski Patrol's great video (here) posted on the Backcountry Skiing Canada web site for a concise summary of details to Feb 9th, and some excellent video footage of a Size 2.5 avalanche running on the Goat Slide path near Whitewater (with crown height to 2.5m).

Another 20-30 cm of wet snow fell up to 1900m on Thursday and ended with a 1-2cm thick crust on all aspects below this elevation. Since then, up to 30cm additional snow has fallen (mostly near Nelson) and brings the recent storm snow total to 65-100cm, creating touchy storm slabs at all upper elevations and aspects. Snowfall amounts have been highest around Kootenay Pass. Slabs have been reported as very reactive to human triggers and are sitting on a variety of surfaces; including scoured surfaces in wind exposed terrain, surface hoar (size 2-3 mm) in sheltered locations, and sun crust on steep solar aspects. Snowpack tests near the Valhallas have given moderate, propagation-likely results down 50-70cms on the Feb 3rd interface. Areas with a shallower snowpack (less than 150 cm) have a generally weak snowpack structure with sugary facets near the ground. This includes shallow alpine slopes and most of the Rossland range. It is possible for storm slab avalanches to step-down to these deeper weak layers, resulting in large, destructive avalanches.