Avalanche Forecast

Fair

An arctic ridge of high pressure should dominate for Saturday resulting in clear, cold conditions. Unsettled conditions are expected for Sunday. The edge of a weak low pressure system from the coast should result in light snowfall on Sunday night/Monday morning but the timing/track/intensity still remains somewhat uncertain.Saturday: Mostly sunny, treeline temperature around -20C, ridgetop wind light NESunday: A mix of sun and cloud, scattered flurries 0-2cm, treeline temperature around -16C, ridgetop wind increasing to 30-50 km/h SE-SW during the daySun. Night/Monday: Cloudy in the morning, clearing during the day, snowfall 1-5cm overnight, treeline temperature around -5C, ridgetop wind 40-60 SW-W

On Thursday, we received reports of several loose, moist avalanches up to size 2. On Wednesday, we received reports of several natural size 2.5 avalanches from steeper terrain features on south and west aspects triggered by the sun. Also reported was a size 1 skier-triggered wind slab and three size 1 cornices triggered by explosives near Fernie.

The primary concern remains a persistent slab that sits on a stubborn persistent weak layer consisting of a crust, facets, and/or surface hoar. The layer continues to show a high degree of sensitivity to human triggers. Wide propagations and remote triggering remain a concern. In the thinner snowpack areas such as the Crowsnest and northern Elk Valley, the slab is typically 30-60cm thick. In thicker areas such as the Flathead and around Fernie, the slab typically varies in thickness from 70-150cm. Check out the South Rockies Blog for a new video discussing the persistent weak layer and the current avalanche problem. Variable winds have transported some of the surface snow, building wind slabs on leeward slopes. Large cornices remain a concern along ridge lines and threaten the slopes below. South facing slopes have formed a sun crust on the snow surface. New surface hoar formation up to 4mm and near-surface faceting are also being reported. A weakness at the base of the snowpack may still exist in isolated areas of the region but triggering has become unlikely.