Bulletin d’avalanche

Northwest Coastal

Dec 25 – 26, 2017Avalanche Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

Wed
Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Triggering wind slabs remains possible in exposed terrain. Watch for signs of unstable snow such as cracking or hollow sounds.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Wind slabs are likely lingering around ridge crests and exposed gullies after a strong bout of outflow winds. Wind slabs may be poorly bonded to a buried crust.

Confidence

Moderate - Wind speed and direction is uncertain

Weather Forecast

TUESDAY: Mix of sun and cloud, moderate northwest winds, treeline temperatures around -12 C.WEDNESDAY: Mostly sunny, light winds, treeline temperatures around -15 C.THURSDAY: Mix of sun and cloud, moderate west winds, treeline temperatures around -18 C.

Avalanche Summary

A skier remotely triggered a large (size 2) wind slab in the Shames backcountry area on Sunday. The avalanche started on a steep south-facing rocky ridgetop at 1400 m. Wind slabs were reported to have been building quickly in the area at the time and were reactive to skier traffic.

Snowpack Summary

Strong outflow winds dramatically affected the surface snow, scouring some slopes down to an old crust and forming hard deposits in many other areas. Sheltered areas may still have 20-40 cm of powder from previous storms, but winds have come from a variety of directions and affected much of the terrain. Wind slabs rest on a variety of old surfaces including a thick melt-freeze crust. In some sheltered locations, soft feathery surface hoar crystals may sit above the crust.The snowpack is reported to be generally strong below this crust, with the possible exception of areas around Stewart and northern parts of the region where the late October crust can be found deep in the snowpack. This deep crust has been been associated with weak sugary snow and could possible be triggered in shallow snowpack areas.

Régions couvertes