Avalanche forecast

Northwest Coastal

Jan 21 – 22, 2014Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–4
    Winds have been blowing with enough gusto to redistribute Monday's 10 - 20 cm of new snow into fresh sensitive wind slabs. There's a chance that wind slab avalanches could step down and trigger some of the deeper weaknesses.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    4–7
    Two weaknesses have the potential to surprise folks: Surface Hoar one meter below the surface and very weak basal facets near the ground. Vigilant slope by slope evaluation and/or a modest terrain approach are appropriate at this time.

Confidence

Fair

Weather Forecast

Synopsis: A frontal system takes a small bite out of the ridge Tuesday resulting in very limited precip for the northwest corner of the province. The ridge comes back with a vengeance Wednesday and should persist through the weekend.Wednesday: Freezing Level: Valley Bottom; Precip: Trace Wind: Mod, SWThursday: Freezing Level: 2500m; Precip: Nil; Wind: Lht, SW Strong W at ridgetop.Friday: Freezing Level: 3000m; Precip: Nil; Wind: Lht, Variable, Strong W at ridgetop.

Avalanche Summary

No new observations from Monday.  An anomalous large avalanche was observed on a SW face in the north of the region on Sunday. The deep persistent slab failed naturally resulting in a size 3 avalanche.

Snowpack Summary

The region picked up 10 - 20 cm of new snow on Monday which now hides most of the destruction caused by previously strong winds that left widespread wind loading/wind damaged snow in their wake. Previously warm temps along with a bit of rain at lower elevations has formed a variety of crusts at and below treeline. The early January surface hoar is most active in the north of the region between 900m and 1400m. It was a player during the last cycle even in low angled terrain. Look for it 70 -100 cm below the surface. Professionals continue to keep an eye on the basal facets which can be found down around two meters below the snow surface.

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