Bulletin d’avalanche

Northwest Inland

Dec 31, 2021 – Jan 1, 2022Avalanche Canada
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Archivé · expiré 5 years ago

Danger d’avalanche

Sun
Mon
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

A brief period of calm ! Wind slabs will remain reactive to riders, especially at treeline where they are overlying cold sugary snow.

Problèmes avalancheux

  • Wind Slabs

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

    About 30 cm of recent snow is still available for wind transport. Fresh wind slabs will remain reactive to riders at treeline and above, especially where they are overlying cold weak sugary snow. Older and more difficult-to-trigger slabs are also present on west slopes due to the outflow winds.

    As wind will shift, expect pockets of wind slabs to develop behind terrain features and cross-loaded areas.

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

An arctic ridge of high pressure will briefly build, leading to another clear and cold day heading into Friday. The next round of snow is expected late Friday, with moderate rates of precipitations to invade the northern ranges for the weekend.

THURSDAY NIGHT: Clear / Moderate north winds / Possible temperature inversion with -20 at the valley bottom and -15 at 1500 m.

FRIDAY: Increasing cloudiness / Moderate westerly winds / Possible temperature inversion with -20 at the valley bottom and -15 at 1500 m.

SATURDAY: Snow 10-20 cm / Strong to extreme southwest winds / Possible temperature inversion with -15 at the valley bottom and -10 at 1500 m.

SUNDAY: Periods of snow 5 cm / Strong southerly winds / High of -8

Avalanche Summary

A small (size 1) wind slab avalanche was easily triggered by a snowmobile Wednesday on a convex roll at treeline. 

Few natural wind slabs (size 1) avalanches were reported from open slopes at treeline around Telkwa and Hudson Bay.

If you are out in the mountains please consider filling out a Mountain Information Network report.

Snowpack Summary

The region received 10-15 cm of new snow Wednesday night, along with strong northerly winds. Fresh and reactive wind slabs have formed in open areas at treeline and alpine, predominantly on south aspects. 

In some areas, recent wind slabs are sitting on a thick layer (30-40 cm) of weak surface snow (faceted grains) due to last week's cold temperatures.

Significant faceting was also observed over the thick early December crust, which can still be found down 70 cm around 1800 m. 

Snowpack depth at treeline typically ranges from 150-230 cm, with higher values in the western part of the region and tapering to the east. 

Terrain and Travel

  • Sheltered slopes at lower elevations will offer the best riding.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Régions couvertes