Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Rossland, St. Mary, Ymir.
Another warm-up brings rising avalanche risk.
Uncertainty remains about cornice falls or surface instabilities stepping down to persistent weak layers.
Confidence
High
Avalanche Summary
On Thursday, skier-triggered and natural storm slabs (up to size 1.5) occurred on northerly alpine terrain in Kookanee Provincial park.
Several dry loose avalanches continue to be triggered by skiers in steep northerly slopes, while wet loose avalanches were solar-triggered on southerly slopes.
Expect an increase in avalanche activity with the forecasted warm weather.
Snowpack Summary
A diurnal melt-freeze cycle occurred in the past days. The surface is either moist or capped with a thin crust on all aspects and elevations except for high northerly slopes where up to 30 cm overlies a thick crust from late March. Below these crusts, the upper snowpack is moist.
Several weak layers from early March, mid-February, and late January can be found in the mid and lower snowpack.
The remainder of the snowpack is generally well settled.
Weather Summary
Friday Night
Clear. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level returning to valley bottom.
Saturday
Sunny. 20 to 30 km/h southwest ridgetop wind. Treeline temperature +4° C. Freezing level rising to 2500 m.
Sunday
Sunny. 10 to 30 km/h south ridgetop wind. Treeline temperature +8° C. Freezing level around 3000 m.
Monday
Mostly cloudy with 10 to 15 cm of wet snow or rain. 20 to 40 km/h southeast ridgetop wind. Treeline temperature +6° C. Freezing level around 2800 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avalanche danger is expected to increase throughout the day.
- Avalanche activity is unlikely when a thick melt-freeze crust is present on the snow surface.
- Limit exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- Avoid travelling on slopes below cornices.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
Avalanche Problems
Loose Wet
As surfaces become wet, loose wet avalanches will become more likely on steep south-facing slopes at all elevations.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Persistent Slabs
Several persistent weak layers exist in the upper meter of the snowpack. The likelihood of persistent slab avalanches will increase with each consecutive day of warm weather.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2.5 - 3.5