Bulletin d’avalanche

South Rockies

Mar 24 – 25, 2025Avalanche Canada
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Archivé · expiré 2 years ago

Danger d’avalanche

Wed
Thu
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Avalanche conditions will deteriorate over the next two days as temperatures rise. There is potential for large, destructive natural avalanches on buried weak layers.

Problèmes avalancheux

  • Wind Slabs

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

    Recent snow and southwest wind have formed wind slabs on lee aspects at treeline and above.

  • Persistent Slabs

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

    A persistent weak layer of surface hoar or facets is buried 50 to 100 cm deep. Triggering is most likely on rocky slopes with a convex shape on north and east aspects at treeline and above.

  • Loose Wet

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

    Loose wet avalanches will become increasingly likely with rising temperatures, especially at elevations where surface snow is seeing above-zero temperatures for the first time.

Confidence

Moderate

Avalanche Summary

On Saturday, explosive-triggered storm slabs were also reported up to size 2 and shooting cracks showed signs of instability in wind-affected storm snow near Castle.

Numerous large natural slab avalanches were reported in this MIN from Mear Lake on Saturday. Some of them are suspected to have run on buried weak layers.

Looking forward, we can expect to see an uptick of persistent slab avalanche activity on buried weak layers as warm temperatures weaken the snowpack.

Snowpack Summary

20 to 30 cm of recent snow is becoming moist with rising freezing levels.

A melt-freeze crust is found 40 to 50 cm deep, except on high-elevation north and east-facing slopes.

A persistent weak layer of surface hoar or facets from late January is buried 50 to 100 cm deep. It is most likely to be triggered on steep, rocky, convex slopes on northerly and easterly aspects at treeline and above.

Weather Summary

Monday night

Partly cloudy. 20 to 40 km/h southwest ridgetop winds. Treeline temperature 0 °C. Freezing level 2000 m.

Tuesday

Mostly cloudy. 10 to 30 km/h southwest ridgetop winds. Treeline temperature +3 °C. Freezing level rising to 2600 m.

Wednesday

Sunny. 10 to 20 km/h south ridgetop winds. Treeline temperature +7 °C. Freezing level rising to 3200 m.

Thursday

Mostly cloudy. 20 to 30 km/h southwest ridgetop winds. Treeline temperature +5 °C. Freezing level falling to 2000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avalanche danger is expected to increase throughout the day.
  • The likelihood of deep persistent slab avalanches will increase with each day of warm weather.
  • The more the snowpack warms up and weakens, the more conservative your terrain selection should be.
  • Be aware of the potential for large avalanches due to buried weak layers.

Régions couvertes