Bollettino valanghe

Banff Yoho Kootenay

Mar 19 – 20, 2025Avalanche Canada
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Archiviato · scaduto 2 years ago

Pericolo valanghe

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

In sintesi

Human triggering of avalanches remain very likely.

We are in a dangerous time for decision-making: the danger is less obvious, people want to ski, and the weather is nice. Manage your desires carefully.

Problemi valanghivi

  • Persistent Slabs

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

    A 40-90 cm slab overlies mid-pack facets and depth hoar at the ground. Numerous avalanches have been failing on both these layers (persistent AND deep persistent slabs) and this will not change anytime soon as these problems are slow to heal. Avoid starting zones and be very wary of overhead hazard.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1–2

    If the sun is out, the snow will warm quickly and loose wet avalanches will start to run. These could be a trigger for the deeper layers resulting in much larger avalanches.

Confidence

Moderate

Avalanche Summary

LL ski hill observed a natural size 2.5 slab avalanche out of S aspect and rocky start zone, on Wednesday. Avalanche control in the Field area produced avalanches up to size 3 on Mt Cathedral.

A group digging a snowpit in low angle terrain with no overhead exposure on Observation Peak on March 18th felt a whumph that remote triggered 5-6 avalanches up to size 2.5.

Evidence of a widespread natural cycle in the last 96 hours was observed throughout the region today during a flight.

Snowpack Summary

Over the past 10 days, 40-90 cm of snow has accumulated and settled into a slab, with the deepest amounts found in the Bow Summit area and along the Wapta. This sits on a very weak, faceted mid and lower snowpack and fails easily in snowpack tests. This condition will be slow to stabilize.

Expect a surface crust on solar aspects treeline and below.

Weather Summary

Wednesday night: Cloudy with clear periods and isolated flurries. Alpine temperature: Low -9 °C. Ridge wind southwest: 15-35 km/h

Thursday: A mix of sun and cloud with isolated flurries. Alpine temperature: High -5 °C. Ridge wind west: 20 km/h gusting to 45 km/h

Friday: Mainly cloudy with scattered flurries. Accumulation: 5 cm. Alpine temps: Low -10 °C, High -5 °C. Ridge wind southwest: 15 km/h gusting to 50 km/h

Terrain and Travel Advice

  • Make conservative terrain choices and avoid overhead hazard.
  • Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.
  • Wind slabs are isolated, but may remain reactive.

Regioni coperte