Bollettino valanghe

Northwest Coastal

Feb 3 – 5, 2012Avalanche Canada
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Archiviato · scaduto 15 years ago

Pericolo valanghe

Sun
Mon
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato

In sintesi

Warm temperatures in alpine areas could cause large, unexpected avalanches, especially on south-facing slopes.

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    3–7
    Cornices are expected to become weak with continued warm temperatures and solar radiation.
  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–6
    Rain and warm temperatures have promoted recent avalanche activity at low elevations that has run on a layer of facets buried around 20-Jan. This problem may creep higher in elevation with continued warm alpine temperatures.
  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    3–7
    Recent rain and warm temperatures have promoted avalanche activity on storm slabs. Alpine temperatures are expected to remain high and this problem is expected to continue through the forecast period.

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

Saturday and Sunday: Dry or very light flurries, with alpine temperatures around -2C. Winds expected to be light southwesterly rising to moderate southeasterly. Monday: Clear with sunny spells. Temperatures below freezing at low elevations but alpine areas may see inversion conditions that will elevate temperatures to near zero.

Avalanche Summary

On Friday, slab avalanches up to size 3.5 were reported in response initially to rain and then during the day to intense solar radiation. On Thursday, numerous large (up to size 3) slab avalanches were reported out of lee terrain (SW predominantly) along Bear Pass during the warming period as the snow turned to rain. Lower elevations were especially active.

Snowpack Summary

Total snowpack depths pushing 5m at treeline are at new record levels for this time of year. Recent warm temperatures helped settle storm snow into a touchy surface slab at lower elevations. Other weaknesses can be found within the upper snowpack and the Jan. 20th facets down around 150cm. These create the potential for large step-down avalanches, but things seem to be settling rapidly. Strong winds associated with recent storms means large weak wind slabs and cornices on lee and cross-loaded terrain. Most snowpack concerns are limited to the surface layers. However, large triggers such as cornice falls and smaller avalanches stepping-down could affect deeper weaknesses.

Regioni coperte