Bollettino valanghe

Purcells

Feb 5 – 6, 2012Avalanche Canada
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Archiviato · scaduto 15 years ago

Pericolo valanghe

Tue
Wed
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–6
    Watch for tender cornices at ridge tops. They may be destructive by themselves and they may be a trigger for the slope below.
  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    3–6
    Recent avalanche activity indicates that deeply buried weak layers are still triggerable. A skier, sled or cornice fall could trigger a large avalanche, especially in thin snowpack areas or on unsupported, rocky terrain.

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

A ridge of high pressure will remain imbedded over the region for the forecast period. Winds will be mostly light and southwesterly with alpine temperatures remaining well below freezing.

Avalanche Summary

Since the recent warming, numerous large and destructive avalanches (to size 3.5) were reported in the region. Most of the avalanches were specific to south-facing alpine features. Some of these avalanches were initiated by cornice fall. Others were loose, wet avalanches that, in some cases, stepped down to basal weaknesses. On Saturday a skier was injured in an avalanche near Kimberley. Details were patchy at the time this bulletin was written. I expect that avalanche activity will decrease with forecast cooling.

Snowpack Summary

The big story has been the recent weather. Over the weekend sun exposed slopes at upper elevations became moist and cornices weakened due to solar radiation and increased alpine temperatures. With forecast cooling these slopes will gain strength and a crust will develop on most slopes that were sun-affected.On shaded aspects, lingering wind or storm slabs should have gained considerable strength, but may show sensitivity to rider triggers; especially on steeper slopes and convex rolls. Below this sits a fairly well settled mid-pack. There are, however, a few exceptions. The Jan. 13th SH/FC combo has been reactive. As well, the mid December facet/surface hoar layer is buried approx. 80 cm on the east side and 200+ cm on the west side and has been more reactive in the Purcells than any other region. There are also basal facets at the ground which will continue to remain a concern, especially in the thin snowpack parts of the region. Snowpack depths at 2000m sit near 2m deep. If you're traveling around the mountains, it's a good time to take notice of what layers are developing (surface hoar/ crusts) that may become an issue once buried.

Regioni coperte