Bulletin d’avalanche

Banff Yoho Kootenay

Apr 5 – 6, 2025Avalanche Canada
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Archivé · expiré last year

Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué

Points saillants

Solar radiation will peak Sunday. Start early, and finish early while the hazard is lower.

Areas East of HWY93N and around the Lake Louise ski hill back country have a much thinner snowpack, making it more susceptible to human triggering

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1.5–3

    Below the recent snow, a 30-80 cm slab sits on the weak lower snowpack. On all but high north aspects, recent sun crusts and the March 27 rain crust cap this slab, providing some security. Use extreme caution in higher, thinner areas or when these superficial crusts are weak or are breaking down.

  • Loose Wet

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

    Crusts almost everywhere on solar aspects, solar inputs will still affect rocky areas. As heating develops, higher and shaded slopes will become affected. Sluffing off of steep rocky faces should be expected and cornice failures are more likely. Isolated wind slab may found in wind prone areas.

Confidence

Moderate

Avalanche Summary

No new activity was observed or reported in this subregion on Saturday.

Snowpack Summary

Surface crusts on solar aspects up to ~2800 m. Up to 30 cm of dry snow on north slopes at higher elevations. On south aspects, this 30cm contains several crusts

Below this, a prominent rain crust (Mar 27) is found everywhere up to at least 2300m. The strength and extent of this crust varies area to area

Below this, a 30-70 cm slab of dense snow overlies another 40-70 cm of weak facets. This is the main problem in the snowpack and is of particular concern when the crusts above it are weak

Weather Summary

Daytime solar radiation is the most important input to the snowpack right now.

Tonight: Clear. Alpine temp: Low -2 °C. Mostly light ridge wind occasionally gusting to 30 km/h. Freezing level at valley bottom. Weak temperature inversion.

Sunday: Sunny. Alpine temps: High 5 °C. Ridge wind light to 25 km/h. Freezing level: Up to 3100 metres on solar aspects.

Terrain and Travel Advice

  • Start your day early and be out of avalanche terrain during the heat of the day.
  • Be mindful that deep instabilities are still present and have produced recent large avalanches.
  • The likelihood of deep persistent slab avalanches will increase with each day of warm weather.
  • Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.
  • Avalanche danger will increase as the surface crust breaks down.

Régions couvertes