Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kootenay Boundary, Kootenay Pass, Norns, Rossland, Ymir.
Seeking dry snow after the warmup may lead you into terrain with lingering persistent slab hazards.
Remain cautious on high northerly slopes & areas without a supportive surface crust.
Confidence
Moderate
Avalanche Summary
Sun: Numerous naturally triggered size 1-2 wet loose avalanches occurred across the region.
Sat: A natural size 3 persistent slab was seen on Evening Ridge (photo below). Several wet loose and wet slabs also occurred in the region.
Fri: Explosives control produced a size 3 persistent slab on a northwest-facing feature at 2100 m
Looking forward: With cooler temperatures forecast, persistent layers should be less likley to trigger and wet avalanches will be unlikely.
Snowpack Summary
A melt-freeze crust or moist snow cap the snowpack on all but high elevation northerly slopes, where you may still find dry but wind-affected snow. Two concerning weak layers are present in the mid snowpack: facets/surface hoar or a thin crust from mid-February buried 40-60 cm, and faceted snow/surface hoar/crust from late January buried 60-90 cm. These layers were active during the warmup, but should become less triggerable as the snowpack cools and surface crusts strengthen. They remain most concerning at upper elevations where a strong surface crust is absent.
Weather Summary
Monday Night
Mostly clear. 15 to 30 km/h variable ridgetop wind. Freezing level 1700 m, then falling to valley bottom. Treeline temperature low of -6 °C.
Tuesday
Mostly cloudy. 15 to 20 km/h south ridgetop wind. Freezing level rising to 1500 m. Treeline temperature around -3 °C.
Wednesday
Cloudy with 5 to 15 cm of new snow overnight. 10 to 20 km/h west ridgetop wind. Freezing level rising to 1500 m. Treeline temperatures around -5 °C.
Thursday
Sunny. 20 to 30 km/h north ridgetop wind. Freezing level rising to 1800 m. Treeline temperature around 0 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be aware of the potential for large, destructive avalanches due to deeply buried weak layers.
- Avalanche activity is unlikely when a thick melt-freeze crust is present on the snow surface.
- Keep in mind that human triggering may persist as natural avalanches taper off.
Avalanche Problems
Persistent Slabs
Weak layers exist between 40 - 90 cm deep. They were active during the warmup and remain a concern where thick and supportive surface crusts haven't formed.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1.5 - 3