Bollettino valanghe

South Columbia

Dec 21 – 22, 2013Avalanche Canada
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Archiviato · scaduto 13 years ago

Pericolo valanghe

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

In sintesi

The snowpack structure is complex and varies throughout the region. A conservative approach is essential.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    3–5
    A buried persistent weak layer of facets, surface hoar, and/or a crust is buried by 40-70 cm of storm snow and may be susceptible to triggering by light load like skiers or riders.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–4
    New storm snow may be touchy to rider triggers, especially in wind effected areas. Further loading and smaller avalanches may trigger buried weak layers and create large- very large avalanches.

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain on Monday

Weather Forecast

The Interior will see generally dry, cool conditions under the current NW flow. A Pacific frontal system will arrive overnight, bringing light- moderate amounts of precipitation and warmer temperatures.Sunday: Cloudy with snow amounts 10-15 cm. Alpine temperatures near -6. Light SW winds. Freezing levels near 1000 m. Monday: Snow amounts 15-25 cm. Alpine temperatures near -5. Moderate westerly ridgetop winds. Freezing levels 1300 m.Tuesday: Cloudy with sunny periods. Alpine temperatures near -7. Ridgetop winds light from the West. Freezing levels near 800 m.

Avalanche Summary

Several natural and rider triggered slab avalanches and loose-snow avalanches up to size 2 were reported on Friday.

Snowpack Summary

Average snowpack depths at treeline range from 100 cm -150 cm. New snow up to 15 cm has buried older wind slabs in exposed terrain at treeline and above. The new storm slab is touchy to rider triggers, and natural loose dry sluffing from steeper terrain exists. Buried down 40-60 cm is a surface hoar, and facet layer. This layer has recently been reactive to riders and natural triggers and both cracking and whumpfing have been noted.Digging deeper down 70-90 cm, is the late-November interface, which consists of a sun crust/ facet combo on steep south facing slopes and larger, proud surface hoar crystals in sheltered areas. This layer is generally considered to be "stubborn" to trigger. However, professionals are keeping a close eye on this layer especially with forecast new load.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