Bulletin d’avalanche

Northwest Inland

Jan 21 – 22, 2016Avalanche Canada
Voir sur la carte
Archivé · expiré 11 years ago

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
1 · Faible
Ouvrir la carte complète

Points saillants

Pay close attention to new snow amounts and whether or not the surface snow is loose or cohesive. Tricky conditions are likely if a cohesive slab forms.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Expect to find fresh wind slabs in exposed lee and cross-loaded terrain. 

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    New snow, wind, and mild temperatures may have helped develop a cohesive slab, which overlies a variety of buried persistent weaknesses. It may be easy for riders to trigger this slab (where it exists), even from low angle terrain.

Confidence

Low - Due to the number of field observations

Weather Forecast

Friday: Cloudy with up to 5 cm of new snow. The freezing level is at valley bottom and winds are moderate from the SW. Saturday: Mainly cloudy with sunny breaks and a chance of flurries. The freezing level is at valley bottom and winds ease to light. Sunday: Mainly cloudy with a chance of flurries. The freezing level is at valley bottom and winds are moderate from the southeast.

Avalanche Summary

There is a new report of two skier controlled size 2 slab avalanches from the Ashman area on Tuesday. These failed on the Jan 5/Dec 26 surface hoar layers down 20-50 cm deep. On Monday, a small natural cornice release triggered a size 2.5 slab avalanche in the north of the region. Skiers also triggered a few slab avalanches size 1-2 in the north. All these avalanches released on the Jan 9 surface hoar layer down 30cm.

Snowpack Summary

An additional 5-10 cm of snow with moderate or strong southeast winds may be enough to form fresh, reactive wind slabs in lee features. In some places this could also activate buried surface hoar in the upper snowpack, generally found between 30 and 60 cm deep. Stay tuned to signs of instability like recent avalanches, whumpfing, and shooting cracks. The mid pack that was reported to be well settled may have now facetted in the shallower areas, and the deeper basal layers are almost certainly facetted and weak. We have not heard of any full depth releases on weak basal layers yet.

Régions couvertes