Avalanche forecast

Northwest Inland

Feb 15 – 16, 2013Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    New snow combined with strong to extreme winds will create fresh and reactive wind slabs. Due to the nature of the winds, watch for loading lower on the slope and in other unusual locations.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–5
    Buried beneath the new snow sits a surface hoar/crust/facet weakness. This may be sensitive to rider triggers in steeper sheltered terrain or over convex rolls, especially at treeline and below treeline elevations.

Confidence

Fair - Due to variable weather conditions

Weather Forecast

Saturday: Light to locally moderate snowfall Friday night, easing on Saturday / Extreme southwest winds on Friday night easing to moderate and northwesterly on Saturday / Freezing level at surfaceSunday: Light snowfall / Moderate west winds  / Freezing level at surfaceMonday: Light snowfall / Light southeast winds / Freezing level at 400m

Avalanche Summary

No recent avalanche observations have been reported.

Snowpack Summary

Depending on the location, light to moderate amounts of new snow have been shifted into wind slabs and overlie older wind slabs that formed earlier in the week. Below treeline, light rain has saturated the surface. In general, between 30-60cm of storm snow sits over a variety of old surfaces which include facets, crusts and isolated pockets of surface hoar (sheltered treeline and below treeline). There is very limited information about the nature of this interface, with the only results suggesting reactivity in sheltered, shady treeline and below treeline slopes (preserved surface hoar). I would stress the importance of digging down to find and test weak layers.A strong mid-pack currently overlies a weak base layer of facets/depth hoar. It is worth noting that the snowpack in general is quite shallow compared to averages; triggering the basal weakness may still be possible from thin spots, rocky outcrops or under the weight of larger triggers such as cornice fall.

Regions covered