Bulletin d’avalanche

North Rockies

Dec 13 – 14, 2023Avalanche Canada
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Archivé · expiré 3 years ago

Danger d’avalanche

Fri
Sat
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
1 · Faible

Points saillants

Make conservative terrain choices. Recent storm snow and buried weak layers may be reactive to human triggering.Reduce your exposure to avalanche terrain if the temperature is above 0°C.

Problèmes avalancheux

  • Wind Slabs

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

    The greatest reactivity may be found in wind-loaded areas where slabs overlie surface hoar. Consider the potential for remotely-triggering slopes above and adjacent to you.

  • Persistent Slabs

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

    Buried surface hoar is most likely to be found at treeline elevations, and most triggerable where the recent rain crust thins, or disappears at upper elevations.

Confidence

Low

Avalanche Summary

On Monday, several small dry loose natural avalanches were reported from steeper terrain features. On Sunday in Pine Pass, a natural size 1 wind slab was observed on a northeast aspect in the alpine. A second-hand report of skier-triggered size 2 was also reported. This avalanche occurred on the peak above the T-bar at Powder King. Read this MIN report for full details.

Human-triggered avalanches remain likely at higher elevations.

Snowpack Summary

Strong winds have likely stripped available snow from south and west-facing slopes, redistributing it onto north and east-facing terrain features.

A concerning layer of surface hoar can be found around 30-50 cm deep.

A crust with sugary facets beneath it can be found just above the ground. The snowpack is still shallow for this time of year. Average snowpack depths at treeline range from 65 to 90 cm.

Weather Summary

Tuesday Night

Mainly cloudy with no precipitation. Alpine wind 50 to 100 km/h from the southwest. Treeline temperatures around -1 C with the potential for an above freezing layer to develop in the alpine and persist for 24 hours.

Wednesday

Warm and windy! Cloudy with a mix of rain and snow 5 to 10 mm. Alpine wind 60 to 100 km/h. Alpine temperatures near +1 C and freezing levels 1500-2800 m.

Thursday/ Friday

Mainly clear. Alpine wind 15 to 35 km/h. Alpine temperatures near -6 and freezing levels drop to the valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Extra caution for areas experiencing rapidly warming temperatures for the first time.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Wind slabs are most reactive during their formation.
  • Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.

Régions couvertes