Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Pass, Moyie, Norns, St. Mary, Valhalla, Ymir.
Dangerous avalanche conditions, natural and human-triggered avalanches are likely. Don't let storm day fever lure you into big terrain features
Confidence
Moderate
Avalanche Summary
On Saturday a large naturally triggered storm slab avalanche was reported. Check this MIN for details.
Several explosive and skier-triggered avalanches (size 1 to 2) have been reported across the region since Wednesday.
With significant snowfall and strong wind in the forecast, the likelihood of both natural and human-triggered avalanches is primed to increase throughout the stormy period and remain elevated for several days.
Snowpack Summary
10 to 15 cm of new snow is expected to fall by the end of the day Monday. This new snow will add to previous storm snow totals of around 10 to 30 cm.
In sheltered areas in parts of the region, surface hoar may be buried 30 to 60 cm.
A widespread crust exists down roughly 50 to 80 cm. In many areas, small, weak faceted grains have formed just above or below this crust.
The mid and lower snowpack is generally well settled.
Weather Summary
Sunday Night
Cloudy with 5 to 15 cm of new snow. 40 to 50 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1500 m.
Monday
A mix of sun and cloud. 25 km/h variable ridgetop wind. Treeline temperature -7 °C.
Tuesday
Partly cloudy with 0 to 2 cm of snow. 30 km/h northwest ridgetop wind. Treeline temperature -10 °C.
Wednesday
Cloudy with 5 to 15 cm of snow. 50 km/h southerly ridgetop wind. Treeline temperature -3 °C. Freezing level 1500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Use increased caution at all elevations. Storm snow is forming touchy slabs.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Avalanche Problems
Storm Slabs
Storm slabs will be building on all aspects, but are expected to be deeper and most reactive on lee northerly and easterly slopes near ridgetops.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2.5
Persistent Slabs
A persistent weak layer consisting of buried surface hoar or a crust/facet combo is buried 40 to 80 cm. New snow may overload these weak layers triggering very large avalanches
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 2 - 3