Bulletin d’avalanche

Coquihalla

Dec 27 – 28, 2022Avalanche Canada
Voir sur la carte
Archivé · expiré 4 years ago

Danger d’avalanche

Thu
Fri
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré

Points saillants

The next storm arrives Monday night and brings with it an additional 15 - 25 mm of precipitation and strong southerly winds. These conditions will continue to build thick storm slabs at higher elevations.

Freezing levels fluctuate between 1000 and 1500 m. Below the freezing line, wet loose avalanches remain reactive to natural and human triggering.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5

    Southerly winds have redistributed 20-40 cm of new snow into deep pockets at higher elevations. Where snow remained dry expect to find pockets of storm slabs that remain reactive to human-triggering. Be especially cautious transitioning into wind-loaded terrain, more reactive deposits lurk in leeward features.

  • Loose Wet

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

    Freezing levels are fluctuating around 1500m. Below the freezing line expect to find a sloppy, saturated snowpack. Watch for unstable snow on specific features, when snow is moist or wet. This problem will persist until the snowpack is frozen again.

Confidence

Low

Avalanche Summary

On Sunday, several natural wet loose avalanches up to size 2.5 were reported from 1800 m and below the Coquihalla highway corridor. A size 2.5 natural storm slab avalanche was observed on an east aspect in the alpine. Backcountry users should expect to see continued evidence of the weekend's natural avalanche cycle.

Please continue to post your observations and photos to the Mountain Information Network.

Snowpack Summary

In the alpine 20 - 40 cm of snow and variable southerly winds have built cohesive slabs in lees. Below treeline rain soaked the snowpack and created a rain crust.

At the start of the storm, fresh snow covered a layer of facetted and unconsolidated snow that formed during the recent cold weather. The snowpack was well settled and bonding well. Snowpack depths reach 200 cm at treeline and higher.

Weather Summary

Monday Night

Cloudy skies. A brief break between storms ends early evening as scattered flurries start up again, 10-15 cm accumulation. Ridgeline low temperature 0 C. Southerly winds 25-40 km/hr. Freezing levels 1200 m.

Tuesday

Cloudy with scattered flurries, 5 cm accumulation. Ridgetop high temperature +3 C. Southerly wind 40 - 60 km/h weakening in the afternoon. Freezing levels rise to 1500m during the day before falling to 1000 m overnight.

Wednesday

Cloudy with scattered flurries, 5 cm accumulation. Ridgetop high temperature 0 C. Westerley winds 20 km/hr. Freezing levels 800-1000 m.

Thursday

Cloudy with scattered flurries, trace accumulation. Ridgeline high temperature -2 C. Southerly wind 20 km/h weakening in the afternoon. Freezing levels 500-1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be alert to conditions that change with aspect and elevation.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.

Régions couvertes