Bollettino valanghe

South Columbia

Dec 25 – 26, 2013Avalanche Canada
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Archiviato · scaduto 13 years ago

Pericolo valanghe

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

In sintesi

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    3–5
    Persistent weak layers of facets, surface hoar, and/or a crust exist in the upper 90 cm of the snowpack. With more load they may be susceptible to triggering, creating large - very large destructive avalanches.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–4
    New storm snow may be touchy and reactive, especially in wind affected areas. Natural avalanche activity is expected. Further loading and smaller avalanches may trigger buried weak layers and initiate large- very large avalanches.

Confidence

Poor - Timing, track, or intensity of incoming weather system is uncertain on Thursday

Weather Forecast

Thursday: Snow amounts 10-15 cm. Alpine temperatures -3. Ridgetop winds light-moderate from the South. An above freezing layer between 1500 and 2500m.Friday: Snow amounts tapering off up to 5 cm. Alpine temperatures near -4. Freezing levels 1000 m.Saturday: Mainly dry, moderate to strong northwesterly winds, freezing level at valley bottom.

Avalanche Summary

On Monday, storm slab avalanche activity up to size 2 was observed on most aspects from 1500 m and up. Most avalanches failed down 20 cm, and were said to be touchy with wide propagations on the most recently buried surface hoar layer. With more snow, wind and warming avalanche danger will be on the rise.

Snowpack Summary

Recent winds from the NW have built pockets of new wind slab on opposite slopes. Up to 40 cm of new snow sits on a surface hoar/ stellar / crust layer buried approximately 20 cm down, and has been very touchy to rider triggers. The new storm snow is settling quickly, however storm slabs have been more reactive where there has been wind effect. Buried down 70 cm is the early December surface hoar, facetted snow, and/or a crust interface. Lately this has been more stubborn to rider triggers. The average snowpack depths at treeline range from 100 cm -150 cm.Digging deeper 70-90 cm is the late-November layer, which consists of a sun crust/ facet combo on steep south facing slopes and larger, proud surface hoar crystals in sheltered areas at lower elevations. This layer is generally considered to be unreactive. However, professionals are keeping a close eye on it.At the base of the snowpack the October crust is most predominant on north-facing alpine slopes with smooth ground cover. Triggering this weakness is unlikely, but if triggered the resulting avalanche would be very large and consequential.

Regioni coperte