Bulletin d’avalanche

North Columbia

Nov 29, 2018Avalanche Canada
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Archivé · expiré 8 years ago

Danger d’avalanche

Fri
Sat
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré

Points saillants

There is a high degree of uncertainty regarding the weak layer that is below this past week's storm snow. Where this nasty layer exists, human triggering may be likely. Conservative terrain choices are key during times of high uncertainty.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2.5
    Widespread storm slabs sit on a weak layer of surface hoar (feathery crystals), and sun crust on steeper south facing slopes. Expect to find deep deposits of snow over this layer in wind loaded areas.

Avalanche Summary

No avalanches were reported in this region on Tuesday. However, we currently have very few observations from within this region. Please post your observations to the Mountain Information Network (MIN). Although not in this region, a notable size 3, human triggered avalanche was reported in the South Columbia region on November 24th. The avalanche reportedly occurred on a northwest aspect, on a lee feature in the alpine and likely ran on a crust near the bottom of the snowpack. The full report can be found on the Mountain Information network. Click here to read the report

Confidence

Low - Due to the number of field observations

Weather Forecast

Overnight WEDNESDAY: Cloudy / Alpine Low -4 / Light to moderate, west wind / Freezing level 500 m.THURSDAY: Cloudy with isolated flurries / Alpine high -4 / Light, west wind / Freezing level 1000 m.FRIDAY: Cloudy / Alpine high -5 / Light, west wind / Freezing level 600 m.SATURDAY: Mix of sun and cloud / Alpine high -7 / Light, north wind / Freezing level 400 m.

Snowpack Summary

Ongoing snowfall since Sunday night brings total recent storm snow amounts to 40-90 cm. This new snow sits on top of a weak layer of surface hoar (feathery crystals) and sun crust on steep south facing slopes. The surface hoar is most pronounced at treeline and below, but it may be found in sheltered alpine areas.At the base of the snowpack is a crust that formed in late October. There have been no reports of reactivity on this layer in the North Columbia region, however with recent snow, winds and high freezing levels, this layer could become active in isolated locations. Total snowpack depths vary greatly with elevation. Recent reports show depths of 120-210cm in the alpine, 80-150 cm at treeline and 10-120 cm below treeline.

Régions couvertes