Bulletin d’avalanche

South Rockies

Dec 18 – 19, 2015Avalanche Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Friday's storm produced enough snow and wind to form fresh wind slabs in exposed terrain. These slabs are likely to remain sensitive to human triggering Saturday.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–4
    Friday's storm was still generating locally heavy snowfall and moderate to strong SW winds late Friday evening. Fresh wind slabs will likely be sensitive to rider triggering in wind exposed areas through the weekend.

Confidence

Low - Due to the number of field observations

Weather Forecast

A strengthening storm system is expected to make a big impact on the coast this weekend, but very little of that system is expected to spill into the Southern Rockies. SATURDAY: Freezing level at valley bottom. Trace of snow possible. Moderate W/SW winds. SUNDAY: No new snow expected, freezing level at valley bottom, strong SW winds. MONDAY: Trace to 2cm of snow possible, freezing level at valley bottom, strong SW winds.

Avalanche Summary

Control work on Friday produced 5 to 10cm thick wind slabs that ran as large as size 1.5 in isolated terrain features. No other activity to report.

Snowpack Summary

The series of recent storms has left us with around 40-60 cm new snow sitting on a firm rain crust. For the most part, the new snow has bonded well to this rain crust, although potentially unstable wind slabs could exist where wind-pressed snow rests directly on a slippery crust below. A previous weak layer from early December consists of crust, surface hoar, and/or facets and is typically down 70-90cm. Around 20-30cm below this interface is a rain crust from mid-Nov with a thick layer of facets below it. Both the early-Dec and mid-Nov layers have become dormant and are likely being capped at treeline and below by the more recent rain crust layer. However, these layers may still be reactive to heavy triggers such as cornices or smaller avalanches stepping down.

Régions couvertes