Bulletin d’avalanche

Northwest Coastal

Apr 3 – 4, 2022Avalanche Canada
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Archivé · expiré 4 years ago

Danger d’avalanche

Tue
Wed
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Slabs may be most reactive around ridges and steep, unsupported features or where they have formed over a crust.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1.5–2.5

    Large cornices have become noticeably large and looming. Cornice falls have the potential to trigger avalanches on the slopes below. 

  • Storm Slabs

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

    Slabs may remain reactive as steady winds continue to move the fresh snow. With recent strong easterly winds, slabs may lurk further downslope or in less common locations.

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Sunday night: Unsettled with isolated flurries and starry breaks, up to 5 cm. Moderate southeast-east wind. Ridgetop low -9 C.

Monday: Cloudy with isolated flurries and sunny breaks, trace to 10 cm. Moderate to light southwest wind. Ridgetop high 0 C.

Tuesday: Flurries starting late Monday evening, 5-15 cm. Moderate southwest-west wind. Ridgetop high -4 C.

Wednesday: Snow, 15-25 cm. Moderate south wind. Ridgetop high -4 C.

Avalanche Summary

Explosives triggered storm slab avalanches to size 2 (and one 2.5) late Saturday and early Sunday morning in the northern end of the region.

On Thursday, wind slabs to size 1.5 were reactive to skiers, reported on northerly aspects with crown depths 15-40 cm. On Wednesday, explosives in the north of the region triggered storm slabs to size 2.

Snowpack Summary

Around 20 cm fresh snow fell by Sunday morning with strong overnight winds, building slabs in the alpine and tree line and more reactive deposits in lee terrain. Now down 20-50 cm, a crust can be found on all aspects and elevations except high elevation north-facing terrain. In the north of the region, small surface hoar may be found above this crust. 

A weak layer of surface hoar from mid-March buried 70-120 cm deep can still be found but is considered dormant around the Terrace area. However, in the far north of the region, it produced large avalanches last weekend and continues to display poor (sudden fracture characteristics) results in snowpack tests.

Terrain and Travel

  • Make conservative terrain choices and avoid overhead hazard.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Régions couvertes