Bulletin d’avalanche

Northwest Coastal

Jan 2 – 3, 2016Avalanche Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

Mon
Tue
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

If solar radiation is strong and alpine temperatures are warm on Sunday, loose wet avalanches may occur on steep, sun-exposed slopes.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–3
    Recent winds have been highly variable across the region, and wind slabs may exist on a variety of aspects. They may be particularly reactive in areas where they overlie recently buried surface hoar.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–4
    This is the piece of the puzzle that won't let me drop the danger rating to LOW. The consequence of triggering a buried surface hoar weakness is high, although the likelihood of triggering seems to be getting lower.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Sunday will likely mark the last day of the dry ridge of high pressure. A temperature inversion is still expected with above-freezing temperatures and light ridgetop winds. On Monday and Tuesday, expect cool and unsettled weather with light flurries, moderate southeast winds and freezing levels at or near valley bottom.

Avalanche Summary

Aside from a few size 1 wind slab avalanches in the far north of the region, no new avalanches have been reported.

Snowpack Summary

Snowpack surfaces are highly variable. Temperature inversions and solar radiation have come into play, and depending on the time of day, sun-exposed slopes at higher elevations may be either moist or refrozen. On shaded slopes, 25-40 cm of storm snow from Boxing Day continues to facet, and new surface hoar has been reported at all elevations. In areas where recent winds have been light, shaded slopes will likely provide unconsolidated powder. In areas where winds have been stronger, reactive wind slabs may exist, especially in areas where the the slab overlies surface hoar buried by the boxing day storm.Professionals in the region are still keeping an eye on a few other surface hoar layers that developed throughout December which are now buried in the top 100cm. Although these layers may be gaining strength, they are worth keeping an eye on, especially on steep unsupported slopes at treeline and below. In colder and shallower snowpack areas watch for weak basal facets.

Régions couvertes