Bulletin d’avalanche

Banff Yoho Kootenay

Feb 10 – 11, 2015Parks Canada
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Archivé · expiré 12 years ago

Danger d’avalanche

Tue
Wed
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué

Points saillants

Avalanche control will be conducted on Mt. Stephen, Mt. Dennis, and on Mt. Hector on Tuesday. Please no skiing or climbing in these areas.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    2–3
    Fifty to 90 cm of storm snow exist on the January 30th crust interface. A poor bond exists at this interface and large avalanches have been observed running on this layer. Huge propagations are still possible.
  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3
    A weak temperature crust overlies isothermal conditions at treeline and below elevations. Many loose wet avalanches that have gouged down to ground have been observed in past 48 hours.
  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    2–3
    The base of the snowpack remains weak due to basal depth hoar/facets. Additional snow load, or a storm slab failure may trigger large to very large avalanches in thin snowpack areas.

Weather Forecast

A weak freeze overnight with freezing levels rising to 1800m on Tuesday. Some flurries forecasted but little in the way of accumulation.

Snowpack Summary

45 - 70 cm of recent storm overlies a crust from January 30th. The recent heavy precipitation, and warmer temperatures have created very touchy storm slabs over top of the January 30th crust interface.  Despite a weak freeze last night isothermal conditions persist at treeline and below.

Avalanche Summary

Avalanche control over the past three days in Banff, Yoho Park and Koorenay Park have produced numerous avalanches up to size 3. Many of the avalanches started dry and turned wet at lower elevations. Also, evidence of a widespread cycle up to size 3.5 throughout the forecast region. Some avalanches running close to full path.

Confidence

Freezing levels are uncertain

Régions couvertes