Bollettino valanghe

Kootenay Boundary

Mar 6 – 7, 2012Avalanche Canada
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Archiviato · scaduto 15 years ago

Pericolo valanghe

Thu
Fri
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Apri la mappa completa

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–4
    Generally lurking below ridgecrests, behind terrain breaks, and in gullies. Wind slabs likely need a bit more time to settle out and gain strength. Shifting winds mean they may be in unusual places.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    3–6
    Persistently weak buried surface hoar demands continued diligence and conservative decisions. The potential for remote triggering, step down avalanches, and wide propagations, makes this weakness particularly tricky to predict. Watch cornices.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–4
    Formally touchy weaknesses within the recent storm snow likely gaining strength, but remain a concern on both convex & unsupported features. It'll take a bit of time for the pack to adjust to this last storm. Solar radiation could trigger a surprise.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Until yesterday the weather story was all about snow with the last storm starting warm and finishing cold. Monday overnight a cold front came through. Looking forward the story for Wed & Thurs is sunshine - warm temperatures and SOLAR WARMING. Freezing overnight. Friday becoming cloudy, maybe flurries ahead of the next forecast system.

Avalanche Summary

Poor visibility most of the day limited observations. In the west side of the region reported avalanches were smaller and seem to be limited to the storm snow. In the east, where more storm snow fell avalanches were much larger. For example near Wyndell a large natural slide buried a sled access road near valley bottom. Some remotely triggered and accidentally triggered slides reported by skiers that were 70 to 100 cm deep. Neighbouring areas reported a widespread, large avalanche cycle and I'd be surprised if something similar didn't occur in the eastern part of the region. Looking forward I think we'll see some surprising avalanches triggered by warm temperatures & sun over the next few days as the snowpack slowly adjusts to this past storm.

Snowpack Summary

Freezing level somewhere around high below treeline or low treeline elevations (say 1600m or so) meant rain below and snow above. The west received another 10 cm while the east saw as much as 40 cm on Monday. I'd guess the storm snow total is around 70 cm. Valentines Surface hoar layer now buried beneath as much as 120 to 140 cm! Stability tests show the deep layers are hard to trigger but there's huge potential for propagation.

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