Bulletin d’avalanche

Purcells

Dec 1 – 2, 2022Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

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

Stiff pockets of wind slab may be lurking behind terrain features like ridges and ribs. The best riding is where the snow is deeper and provides support but stick to moderate slope angles, and seek out wind-sheltered places.

Hitting early-season hazards like rocks and stumps can also be a day wreaker.

Problèmes avalancheux

  • Wind Slabs

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

    Isolated pockets of stiff wind slab may be reactive to rider triggering on leeward slopes and behind terrain features.

    Thin early-season snow depths mean you'll be searching for deeper areas to ride; that'll take you to where a cohesive snowpack is most likely (vs. sugary facets everywhere else). Selecting moderate (less steep) slopes will help manage both early-season hazards like hitting rocks and stumps and avalanche hazards.

Confidence

Moderate

Avalanche Summary

No recent avalanche observations from the field.

On November 28th a natural wind slab size 2 was reported and the interesting thing is that it scrubbed to the ground and ran quite far.

Snowpack Summary

Upper Snowpack: 5-15 cm of new low-density snow adding 20 to 30 cm of snow from the past week. In windy, alpine areas it may have been hardened into a slab, but generally it's soft and faceting (turning into sugar).

Lower Snowpack: Below the recent snow are a couple of surface hoar layers or extra faceted snow. But generally, it doesn't really matter because it's all mostly soft facets (in representative places that are out of the wind near treeline)

There isn't much holding everything together other than wind hardening. In most places the lack of structure doesn't support slab avalanche (only loose dry) but in wind-loaded lee slopes where the snowpack is thicker and more cohesive the situation could be different.

In the alpine, snowpack depths range from 50-150 cm. At treeline there is around 50-100 cm. Below treeline is thin and scratchy. At all elevations there are many early season hazards like rocks and stumps.

Weather Summary

Wednesday Night

New snow 5-10 cm, strong wind from the southwest and temperatures are steady -13 to -20.

Thursday

Light flurries in the morning, some clearing and periods of sunshine by the afternoon. Wind moderate from the southwest and temperatures near -20.

Friday

Mix of sun and cloud, light West wind and temperatures near -15.

Saturday

Mix of sun and cloud, some flurries, light West wind and temperatures near -15.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be especially cautious as you transition into wind affected terrain.
  • Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.

Régions couvertes