Bulletin d’avalanche

Kootenay Boundary

Mar 21 – 22, 2025Avalanche Canada
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Archivé · expiré 2 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré

Points saillants

15 to 25 cm of recent snow and southwest wind have formed fresh storm slabs.

Expect strong solar radiation to increase the likelihood of triggering slabs.

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 very large and destructive avalanches.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2

    15 to 25 cm of recent snow and southwest wind have formed fresh storm slabs.

    Expect strong solar radiation to increase the likelihood of triggering slabs.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–1.5

    Expect strong solar radiation to trigger small wet loose avalanches and increase the likelihood of triggering slabs.

Confidence

Moderate

Avalanche Summary

On Thursday, numerous skier triggered storm slabs up to size 1.5 and one size 2 persistent slab were reported. They occurred primarily on northerly and easterly aspects. Here's one example.

Additionally, a naturally triggered size 3 persistent slab was reported on northeast aspect in the alpine. It was likely triggered by either rapid loading or a cornice fall.

Snowpack Summary

15 to 25 cm of recent snow and southwest wind have formed fresh storm slabs reactive to human triggers.

Concern remains for triggering persistent slab avalanches. These layers include:

  • Facets/surface hoar/crust from early March buried 40-70 cm.

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

  • Facets/surface hoar/crust from late January buried 100-160 cm.

The lower snowpack is well settled and strong.

Weather Summary

Friday night

Cloudy with 0 to 10 cm of snow (isolated areas could receive up to 20 cm). 10 to 20 km/h west ridgetop winds. Treeline temperature -8 °C. Freezing level valley bottom.

Saturday

Mix of sun and cloud. 10 to 20 km/h west winds. Treeline temperature -4 °C. Freezing level 1500 m.

Sunday

Mostly cloudy with 5 to 15 cm snow. 10 to 20 km/h southwest ridgetop winds. Treeline temperature -4 °C. Freezing level 1400 m.

Monday

Moslty cloudy with 0 to 5 cm of snow. 20 to 30 km/h southwest ridgetop winds. Treeline temperature 2 °C. Freezing level rapidly rising to 2200 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
  • Use small, low consequence slopes to test the bond of the new snow.
  • Be aware of the potential for larger than expected storm slabs due to buried surface hoar.
  • Even brief periods of direct sun could produce natural avalanches.

Régions couvertes