Bollettino valanghe

Cariboos

Mar 20 – 21, 2012Avalanche Canada
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Archiviato · scaduto 15 years ago

Pericolo valanghe

Thu
Fri
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
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 - Likely
    Dimensione
    1–4
    Recent southwest wind and new snow have developed windslabs in the alpine and at treeline. These windslabs may take a few days to settle and bond.

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–4
    Cornices are very large. Forecast new snow and strong winds may cause new weak growth that may fall off naturally.

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    3–7
    The mid-February weak layer of facets, surface hoar, and crusts has been buried for about six weeks. Reports of avalanches releasing on this layer are becoming less frequent. Avalanches that do release on this layer may be very large and destructive.

Confidence

Fair - Forecast snowfall amounts are uncertain on Wednesday

Weather Forecast

Snow is expected to continue during the day on Tuesday and taper off during the night, bringing an additional 5-10 cm for the interior regions by Wednesday morning. A weak upper ridge is forecast to build over the southern interior on Wednesday that should cause light southwesterly winds and scattered flurries. There may be periods of sun in the eastern Monashees and Selkirks, and in the northern Purcells. A weak upper trough is forecast to push up from the U.S. border on Thursday bringing moderate precipitation to the southern and Eastern regions. Freezing levels are expected to climb up to about 1800 metres as the trough advances. The upper flow is expected to shift to the southeast with light alpine winds, broken skies with sunny periods, and freezing levels up to 1800 metres in the south and east regions of the interior.

Avalanche Summary

We have one report from Monday of natural avalanches up to size 3.5 on southerly aspects failing down about 100-150 cm on the mid-february persistent weak layer (PWL). Avalanches releasing on this layer are becoming less frequent. Large triggers like cornice fall may initiate a release on the PWL.

Snowpack Summary

Strong southerly winds combined with new snow to develop thin new windslabs in the alpine and at treeline. Sunny breaks on Sunday caused moist snow up to about 2400 metres on solar aspects and up to about 1500 metres on all aspects. The recent storm snow is reported to have settled and bonded in most areas. Recent cornice growth has made cornices unstable. The new snow has added to the well consolidated storm slab that overlies weak surfaces that formed early February. This interface, which lies between 1 and 2 metres below the surface, includes a widespread surface hoar instability that, depending on aspect and elevation, may exist in combination with facets or crusts.

Regioni coperte