Bulletin d’avalanche

Kootenay Boundary

Jan 6, 2019Avalanche Canada
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Archivé · expiré 8 years ago

Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré

Points saillants

Storm slabs have formed with recent snowfall and wind. Expect deeper and more reactive deposits in wind-loaded terrain.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    Storm slab avalanches continue to be reported in the region. Recent winds have deposited snow in immediate lee features below ridges and roll-overs. Expect to find deeper and more reactive deposits of snow in wind-loaded areas.

Weather Forecast

SATURDAY NIGHT: Flurries, up to 10 cm snow. Moderate increasing strong south-southwest wind. Freezing level dropping from 1600 m.SUNDAY: Flurries, 5-10 cm snow. Moderate southwest wind with strong gusts. Freezing level dropping below 1000 m.MONDAY: Cloudy with sunny periods and isolated flurries. Light west wind with moderate gusts. Freezing level below 600 m. TUESDAY: Cloudy with flurries, trace to 5 cm snow and continuing into Wednesday. Moderate to strong wind. Freezing level below 600 m.

Confidence

Moderate -

Avalanche Summary

On Friday, explosives triggered storm slab avalanches size 1.5-2.5 and natural avalanches size 1-2 were reported. Recent winds have redistributed snow and skiers triggered two small wind slab avalanches in lee features just below ridge-top. During the day Thursday, storm slab avalanches to size 2 failed naturally and were triggered by explosives. Storm snow was reactive to skier traffic with shooting cracks up to 20 m. Visibility was poor and limited observations were reported.

Snowpack Summary

15-30 cm recent snow has been redistributed by winds forming slabs in lee features and scouring exposed terrain. A zipper crust may be found within the storm snow resulting from a freezing mist on January 2, most likely found below 2150 m.Below the storm snow, several layers of small spotty surface hoar and thin crusts have been observed in the top 60 cm of the snowpack. Some snowpack tests suggest the snow may be poorly bonded to these layers in isolated areas. However, the main weak layer worth considering is still the widespread weak layer that formed in early December. The layer consists of a rain crust with a weak layer of feathery surface hoar and sugary facets and can be found 70 to 110 cm cm below the surface. Although there has not been a reported avalanche on this layer in over a week, a large load like a cornice falling could be enough to reawaken it.

Régions couvertes