Avalanche forecast

Northwest Coastal

Jan 20 – 21, 2014Avalanche Canada
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Avalanche danger

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

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    New snow and wind Monday will likely form fresh sensitive wind slabs, but they should be quite manageable. Soft new wind slabs will cover stubborn old wind slabs that may still be sensitive to human triggering on convexities and thick to thin spots.

  • 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.Monday: Precip: 5/10mm 5/15cmTuesday: Freezing Level: Inversion, Above Freezing Air from 1500 2000m; Precip: Nil; Wind: Mod, SW.Wednesday: Freezing Level: 1500m; Precip: Trace Wind: Mod, SWThursday: Freezing Level: 3000m. Precip: Trace; Wind: Mod, SW

Avalanche Summary

A few small wind slabs were reported from N/NE facing terrain Sunday. A large avalanche was observed on a SW face in the north of the region. The deep persistent slab failed naturally resulting in a size 3 avalanche.

Snowpack Summary

Previously strong winds have left widespread wind loading/wind damaged snow in their wake. Most of these wind slabs are probably growing old and tired but may still pose a problem in bigger terrain. Warming 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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