Avalanche forecast

Northwest Inland

Feb 13 – 14, 2013Avalanche Canada
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Avalanche danger

Fri
Sat
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
    Generally light snowfall and extreme winds are expected to add to the current wind slab problem. Watch for triggering below rolls and in the lee of ridge crests.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–6
    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.

Weather Forecast

Thursday: Light to locally moderate snowfall / Strong to extreme west winds / Freezing level at 700mFriday: Moderate snowfall / Extreme southwest winds / Freezing level at 900mSaturday: Light snowfall / Moderate southwest winds / Freezing level at 500m

Avalanche Summary

No recent reports, but we have had very few observations.

Confidence

Fair - Forecast snowfall amounts are uncertain

Snowpack Summary

Recent light to locally moderate snowfall has likely set up new wind slabs in exposed lee areas. Previous buried surfaces lie buried approximately 20-40cm below the surface. These vary from facets to crusts and isolated pockets of surface hoar (sheltered treeline and below treeline). There is very limited information about the nature of the 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