Bulletin d’avalanche

Banff Yoho Kootenay

Jan 18 – 19, 2013Parks Canada
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Archivé · expiré 14 years ago

Danger d’avalanche

Fri
Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré

Points saillants

Pay attention to localized wind-loading. Where present, it could be rapidly overloading weak layers. Dig into the snowpack and determine whether you want to commit to steeper features.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Recent wind loading have created new wind slabs, predominantly in the alpine. They will certainly be reactive to human loads. A natural size 2 was observed at Bow Summit yesterday. The ensuing strong winds reloaded the slope in a couple of hours.
  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3
    Beware of open areas at tree-line and below tree-line. Surface hoar is well preserved in sporadic locations. In wind-loaded areas, it may be buried deeper, creating a thicker slab to avalanche.

Weather Forecast

Temperatures are forecasted to stay warm over the next couple of days, with freezing levels rising to 1600m. Thankfully the winds should drop to 30-50km/h from the W, which is a welcome change from the honkin' 60-100km/h! We may see a trace of snow tonight/tomorrow. The warmth and the winds remain the key factor to watch.

Snowpack Summary

30 to 50cm of snow sit over the Jan 6th interface.  In several locations in Kootenay and some areas near Sunshine, the Jan 6 interface is a well preserved surface hoar (3 to 5mm in size). Tests show easy sudden planar shears. It's worth digging down to it in a few locations to check if it's present. Alpine features have been blasted by recent wind.

Avalanche Summary

During the wind event over the past few days, several size 1.5 - 2 avalanches have been noted in the alpine. One natural triggered size 2 avalanche near Bow Summit in an open wind-effected lee feature at tree-line. We may see continued sporadic small avalanches tomorrow with strong winds forecasted, although most of the snow has been moved already.

Confidence

Régions couvertes