Bulletin d’avalanche

Northwest Inland

Dec 25 – 26, 2019Avalanche Canada
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Archivé · expiré 7 years ago

Danger d’avalanche

Fri
Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible

Points saillants

Recent snow, continued flurries, and wind continue to promote slab development at upper elevations.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Flurries and recent snow has been and continues to be redistributed by wind. Wind slabs will be most reactive around ridges and in leeward terrain.

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

Tuesday Night: Cloudy with isolated flurries, trace to 5 cm. Alpine temperature -6 C. West wind, 25-45 km/hr.

Wednesday: Mostly cloudy. Alpine temperature -7 C. Southwest wind, 30-50 km/hr.

Thursday: Snow and flurries, 10-25 cm. Alpine temperature -5 C. Southwest wind, 50-85 km/hr. Freezing level rising to 800 m.

Friday: Sun, cloud, and isolated flurries, 5-15 cm. Alpine temperature -6 C. Southwest wind, 15-30 km/hr gusting to 85 km/hr. Freezing level 1200 m.

Avalanche Summary

There have been no recent reports of avalanche activity.

Snowpack Summary

Flurries continue to add to 15-30 cm of snow from early last week. Moderate south-southwesterly winds continue to redistribute loose snow, and have developed wind slabs ridge features and into the alpine.

Reports suggest there are 2 buried layers of surface hoar in the upper snowpack - one down 15-25 cm below the new snow, and another down 25-40. Where wind has scoured the snowpack, a crust from November is at or near the surface. In leeward terrain, this crust is 40-80 cm deep, and may include surface hoar in sheltered openings up to treeline.

Older crusts can be found deeper in the snowpack and are generally breaking down. In areas with a relatively thin snowpack, the base of the snowpack likely consists of weak faceted grains.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Make observations and assess conditions continually as you travel.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Régions couvertes