Avalanche forecast

Northwest Inland

Jan 1 – 2, 2012Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
4 · High
Treeline
3 · Considerable
Below
2 · Moderate
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Watch for continued wind slab development with Sunday night's wind and snow. Unstable cornices will also be a concern at ridgecrests.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–5
    Persistent slabs have now formed at all elevations where the mid December buried surface hoar/crust/facet layers exist. The probability of triggering has decreased, but the consequences of a release remain high.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2
    Storm slabs will reform with forecast weather.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertainfor the entire period

Weather Forecast

Monday: Moderate snowfall from Sunday night will extend into Monday morning. Expect strong southerly winds and freezing levels up to 700m.Tuesday: Light snowfall arriving late in the day, becoming moderate overnight. Winds expected to be strong from the south. Freezing levels will start out at surface rising to 1000m as the precipitation intensifies.Wednesday: Continued moderate snowfall. Strong southerly winds and freezing levels at 1050m.

Avalanche Summary

No new observations from this region.

Snowpack Summary

Strong winds have been the biggest story recently. Exposed windward slopes have been scoured and wind slabs have formed in lee terrain and may be susceptible to human triggering. Expect recent cornice development as well.In the mid-snowpack there is now around 70cms of snow sitting on a surface hoar/crust/facet combo which is the result of the early December dry spell. This crust is widespread and exists in most start zones up to 2000m. Facets can reportedly be found above or below the crust. Prior to being buried, the surface hoar was destroyed by high winds in the alpine, but still coexists with the crust at treeline and below.This interface has been gaining significant strength. Recent tests have produced hard yet sudden collapse results which indicate that it has not gone away. The over-riding slab may still react to a rider trigger, especially in steeper, unsupported terrain features.Beneath this the lower snowpack is well settled and strong.Expect continued wind and storm slab development with forecast wind and snow

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