Bulletin d’avalanche

Banff Yoho Kootenay

Dec 29 – 30, 2025Avalanche Canada
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Archivé · expiré 9 months ago

Danger d’avalanche

Wed
Thu
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

This is the first significant break from all the recent snow, which is a good problem to have.

However, the new snow will take time to settle. Expect wind slabs in exposed terrain and the potential to trigger deeper persistent slabs, especially in areas with a thinner snowpack.

Problèmes avalancheux

  • Wind Slabs

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

    Moderate to strong winds from multiple directions have moved recent snow, creating slabs in alpine and open treeline terrain. There is also more wind in the forecast, which is keeping the likelihood raised. Watch for these as you transition into wind-affected terrain.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–4

    The natural avalanche cycle on this layer has ended, but concern about human-triggered avalanches persists. Be wary of shallow areas, as this has been where the bulk of recent large avalanches have started, going from thin to thick (see avalanche summary).

Confidence

Moderate

  • Uncertainty is due to the fact that deep persistent slabs are particularly difficult to forecast.

Avalanche Summary

A skier-remote size 2 deep persistent slab was reported in Lake Louise backcountry (see picture below). Sunshine Village heli control mainly produced size 2 wind slabs and one deeper size 2. A field team on Paget Peak observed size 1.5 naturals from steep terrain in the Ogden headwall. On Saturday, heli avalanche control on Hwy 93S produced mixed results to size 2.5, and a goat-triggered size 3 above the ice climb Bourgeau right hand shows deep layers remain triggerable.

Snowpack Summary

No snow on Sunday, but there has been 20-30cm of snow since Dec 26th. Variable winds have created fresh windslabs in alpine and open treeline terrain.

There is 40-80 cm over the Dec 15 melt-freeze crust (which is present to ~1800 - 2000m), 80-160 cm over the November facet/crust interface, and, in thinner snowpack areas, facets at the base.

Treeline snow depths range from 100-200cm plus.

Weather Summary

Monday: no snow, with W alpine winds 30-50kmh. Temperatures will be at -10C to -14C at treeline, with above-freezing temperatures on the eastern slopes at the valley bottom.

Tuesday and Wednesday: Much the same with TL temperatures slowly warming over the period.

Link to the weather forecast

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
  • Be mindful that deep instabilities are still present and have produced recent large avalanches.

Régions couvertes