Bollettino valanghe

Cariboos

Dec 3 – 4, 2012Avalanche Canada
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Archiviato · scaduto 14 years ago

Pericolo valanghe

Wed
Thu
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato

In sintesi

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    2–5
    Deep and dense wind slabs are likely in exposed lee slopes and cross-loaded gullies well below ridge crests.
  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    2–6
    Although the likelihood of a release is low, the consequences of a persistent slab release could be significant. These layers may wake-up with additional loading.
  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–4
    Instabilities may exist within or under the recent storm snow (up to 60cm) and may be triggered naturally or by the weight of a person. Expect to find dense wind slabs in exposed north through east facing terrain at all elevations.

Confidence

Poor - Due to limited field observations

Weather Forecast

Synopsis: A frontal system will move through southern BC on Tuesday bringing moderate snow, very strong winds, and slightly rising freezing levels. Unsettled and cooler conditions are expected in the wake of this system.  Tuesday: Moderate snow – 10-20 cm; the freezing level could jump to 1000 m; winds are very strong from the southwest. Wednesday and Thursday: Cloudy with flurries; the freezing level lowers to valley bottom.

Avalanche Summary

There are limited recent observations; however, it is likely that was a natural avalanche cycle on Saturday and into Sunday. Avalanche activity should increase again on Tuesday with forecast moderate snowfall and very strong winds. We welcome all observations at [email protected].

Snowpack Summary

Instabilities may exist within or under the recent storm snow. A surface hoar layer or thin crust may be found at the base of the storm snow, down 40-60 cm, but we have very limited information on the extent or sensitivity of this layer in this region. A second buried surface hoar layer, down about 115 cm, and the early November rain crust (facet-crust combo), over 125cm down in some locations, remain a concern for isolated deep slab avalanches. Average snow depths at treeline seem to be between 140cm and 170cm. In general, snowpack data is sparse in this region and significant variations likely exist from one drainage to another. In short, digging down and making your own observations will be critical to safe slope selection. Any observations from the field are welcome at [email protected].

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