Bulletin d’avalanche

Blue River

Jan 20 – 21, 2024Avalanche Canada
Voir sur la carte
Archivé · expiré 3 years ago

Danger d’avalanche

Mon
Tue
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
Ouvrir la carte complète

Points saillants

Recent natural slab avalanches warrants conservative terrain choices.

Be aware of changes underfoot (transitions into wind stiffened snow) and overhead (ridge wind, and large slopes).

Problèmes avalancheux

  • Wind Slabs

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

    New wind slabs will take time settle. Since natural avalanches are still happening be mindful of what is above you.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3.5

    Two weak layers of surface hoar exists deeper in the snowpack. They have recently been reactive and triggered by people. As the unconsolidated snow settles and forms a slab, a reactive upper snowpack may exist.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3.5

    Basal facets remain a concern in steep, rocky alpine features with thin-to-thick snowpack transitions.

Confidence

Moderate

Avalanche Summary

Large natural wind slabs, up to size 3, were still being reported on Thursday. Earlier in the storm on Wednesday, two persistent slab avalanches (size 1 and 2) were remotely triggered by skiers in the Northern Selkirks. These avalanches occurred on north aspects at treeline. Several natural and skier-triggered storm slabs were reported from alpine and treeline terrain up to size 2.

Snowpack Summary

20 to 30 cm of low-density storm snow is being variably altered by wind and has buried a variety of old snow surfaces. It sits above unconsolidated faceted snow, surface hoar and firm wind-pressed snow in open terrain at treeline and above.

Down 50 to 70 cm a crust, facet, and/or surface hoar layer exists. This may become a problem once the snow above starts to stiffen and form a slab.

130+ cm down another surface hoar layer exists that was buried in early December. This seems to be of most concern above 2000 m where a robust crust doesn't exist above it, or in shallow snowpack areas.

The depth of the snowpack varies greatly throughout the region and weak basal facets are present at the base of the snowpack.

Weather Summary

Friday Night

Cloudy with up to 10 cm of snow. Alpine wind south 10 to 60 km/h. Treeline temperature rising to -13 °C.

Saturday

Cloudy with up to 10 cm of snow. Alpine wind southwest 10 to 50 km/h. Treeline temperature rising to -8 C.

Sunday

Cloudy with up to 5 cm of snow. Alpine wind southwest 10 to 30 km/h. Treeline temperature rising to -5 C.

Monday

Cloudy with up to 5 cm of snow. Alpine wind south 10 to 30 km/h . Treeline temperature around -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Régions couvertes