Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kootenay Boundary, Kootenay Pass, Norns, Rossland, Ymir.
Avalanche conditions remain dangerous.
Stick to low angle, conservative terrain without overhead hazard.
Confidence
Moderate
Avalanche Summary
On Sunday widespread avalanche activity was observed, naturally (including solar induced) and human triggered to size 2.5. Avalanches were observed within the storm snow and on both buried persistent weak layers. Remotely triggered avalanches were also reported on these persistent layers, on north and east facing slopes at treeline.
We expect natural activity to taper off, but human triggering will remain likely.
Snowpack Summary
Storm totals reach 40 to 70 cm. Moderate to strong southwest winds have likely redistributed this snow into deeper and more reactive deposits at treeline and above. Below 1500 m precipitation mostly fell as rain.
This storm snow sits over surface hoar or thin crust from mid-February. Another weak layer of faceted snow /surface hoar/and a crust from late January is buried 60 to 100 cm deep. Both of these weak layers are expected to be more reactive from the heavy snowfall and warm temperatures. The remainder of the snowpack is generally well-settled.
Weather Summary
Monday Night
Cloudy with 10 to 15 cm of snowfall expected for most areas. 20 to 30 km/h south ridgetop wind. Freezing level drops to 1000 m.
Tuesday
Cloudy with another 10 to 15 cm of snow possible over the day. Heaviest amounts expected for Kootenay Pass. 30 km/h south ridgetop wind. Treeline temperature -4 °C. Freezing level rising to 1500 m.
Wednesday
A mix of sun and cloud. 20 to 30 km/h southwest ridgetop winds. Treeline temperature -3 °C. Freezing level rising to 1700 m.
Thursday
A mix of sun and cloud. 40 to 50 km/h southwest ridgetop winds. Treeline temperature -2 °C. Freezing level rising to 1800 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.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.
- Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Avalanche Problems
Storm Slabs
Storm slabs are expected to remain sensitive to triggers, and may produce natural avalanches as storm snow continues to accumulate on Tuesday. Deeper and more reactive slabs have likely formed near ridgelines.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2.5
Persistent Slabs
Heavy snowfall and warm temperatures will stress buried weak layers. Small avalanches have potential to step down and produce very large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1.5 - 3