Avalanche forecast

Northwest Coastal

Mar 19 – 20, 2012Avalanche Canada
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Archived · expired 15 years ago

Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–4
    New wind slabs may form in exposed lee and cross-loaded terrain on Tuesday.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–6
    Cornices are reported to be very large and potentially unstable at this time. A cornice fall could be destructive by itself, and may also act as a trigger on the slope below.

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Tonight and Tuesday: Moderate snowfall - Approximately 5cm overnight and an additional 5-15cm on Tuesday. The freezing level (FL) is around 500m and winds are moderate from the S-SW. Wednesday: Unsettled conditions with convective flurries - 5-10cm. FL is near 500m. Winds easing to light from the south. Thursday: Mainly cloudy with light flurries. No significant accumulation.

Avalanche Summary

There was one report of a Size 2.5 natural slab avalanche on a SW aspect along the highway corridor west of Terrace. The crown was reported to be 45-70cm deep. Otherwise there were no new observations.

Snowpack Summary

The soon to be buried snow surface includes a sun crust on southerly aspects, surface facets or surface hoar in cool shady areas, and pockets of wind slab in exposed terrain. A variety of potential weak layers exist between 60 and 120cm deep. These include surface hoar or facets. There has been no recent activity on these layers but they could wake up with heavy triggers like a large cornice chunk or a snowmobile digging its track in. Cornices in the region are reported to be very large and potentially unstable.

Regions covered