Bollettino valanghe

Banff Yoho Kootenay

Dec 18 – 19, 2025Avalanche Canada
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Archiviato · scaduto 9 months ago

Pericolo valanghe

Sat
Sun
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato

In sintesi

Mt. Dennis, Mount Bourgeau and Eagle Mountain avalanche closure zones are CLOSED on Thursday, December, 18th.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3.5

    More snow will add mass to the slab sitting on top of the mid-pack Nov 22 facet/crust layer and the deeper Nov 13 facet/crust layer. While the likelihood will slowly decrease, particularly below treeline, we still expect to see large avalanches occur on these layers for the next couple of days.

  • Loose Dry

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–2

    With continued strong W/SW winds and snowfall we expect to see dry loose avalanches in steep terrain, especially in couloirs and gullies. Best to avoid this type of terrain until the conditions improve.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2.5

    Ongoing precipitation continues to build storm slabs, while strong SW winds continue to actively redistribute snow into wind slabs in lee terrain at higher elevations. These slabs will remain reactive for the next few days.

Confidence

Moderate

  • Uncertainty is due to limitations in the field data.

Avalanche Summary

Avalanche activity continues with two large naturals reported to us today in Kootenay and Yoho. Both were size 3+ and ran to valley bottom.

Sunshine patrol also triggered a size 2.5 with explosives at treeline that ran on a November crust layer and Lake Louise had a couple size 2's in closed areas that failed from rapid wind loading during the day.

Snowpack Summary

With the continued snow and wind over the past week, there is now a 50-100 cm+ slab overlying the November crust /facet layers. These layers have been active this week with avalanches up to size 3.5, occasionally scrubbing to ground.

Below 2100m, a new crust is now forming below the recent snow as the temperatures cool from the weekend warmup.

Treeline snowpack depths range from 100-180 cm!!

Weather Summary

A persistent westerly flow continues to bring precipitation to the range. Expect a small reprieve overnight Wednesday followed by 10-15 cm starting Thursday afternoon. Skies will dry up throughout the day on Friday but we can still expect small flurries and another ~ 5 cm on Saturday. Temps will be -5 to -10 at treeline with consistent moderate to strong west and southwest winds throughout the period.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.

Regioni coperte