Bulletin d’avalanche

Kootenay Boundary

Mar 22 – 23, 2025Avalanche Canada
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Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Continued snowfall will keep storm slabs reactive and stress buried weak layers. Conservative terrain choices are crucial.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3

    Several persistent weak layers exist in the upper metre of the snowpack. Small avalanches in motion may trigger these deeper layers creating large and destructive avalanches.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–2.5

    Another 10 to 15 cm of new snow will add the existing storm storm slab problem. Wind-loaded slopes will be especially dangerous.

Terrain and Travel Advice

  • Use conservative route selection. Choose simple, low angle terrain with no overhead hazard.
  • Avoid freshly wind-loaded terrain features.
  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.

Confidence

Moderate

Avalanche Summary

Storm slabs have produced many size 1 to 2 avalanches in recent days, including numerous human-triggered slabs in the top 30 cm and larger natural avalanches in alpine terrain.

Two large persistent slab avalanches occurred on Thursday: a skier-triggered size 2 in the Monashees and a natural size 3 in the Selkirks.

Expect continued storm slab activity on Sunday. Persistent slab avalanches will become likely as temperatures warm this week.

Snowpack Summary

Storm slabs will grow on Sunday with 10 to 15 cm of new snow adding to the 15 to 25 cm snow from the previous few days.

Several weak layers in the snowpack are currenlty concerns for triggering persistent slab avalanches:

  • Facets/surface hoar/crust from early March buried 40 to 70 cm,

  • Facets/surface hoar/crust from mid-February buried 60 to 100 cm, and

  • Facets/surface hoar/crust from late January buried 100 to 150 cm.

This complex snowpack combined with dynamic weather makes travel in avalanche terrain dangerous.

Weather Summary

Saturday Night

Mostly cloudy with 0 to 1 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Sunday

Cloudy with increasing snowfall rate and 10 to 15 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Monday

Snow transitioning to rain with 30 to 50 mm in the Monashees and Selkirks and 10 to 20 mm in the Purcells. 60 km/h southwest ridgetop winds. Treeline temperature +2 °C. Freezing level rising to 2400 m.

Tuesday

Cloudy with 10 to 20 mm of rain and then clearing skies in the afternoon. 20 km/h southwest ridgetop wind. Treeline temperature +6 °C. Freezing level 2700 m.

More details can be found in the Mountain Weather Forecast.

Régions couvertes