Avalanche forecast

Northwest Inland

Feb 26 – 27, 2013Avalanche Canada
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Avalanche danger

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

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–5
    Pockets of dense wind slab are likely in exposed lee terrain and cross-loaded gully features. Triggering is possible on steep open slopes and convex rolls.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–5
    Cornices have grown large and weak in recent storms. They may fail with additional growth, daytime warming, or solar radiation.

Confidence

Poor - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Synopsis: Light precipitation until Friday, when a Pineapple Express to the south of the region will spill some moisture over into this region.Wednesday: Mostly flurries, but light snowfall (around 5cm) in higher snow areas in the west. Treeline temperature around -5C. Winds SW around 30 km/h.Thursday: Light snowfall. Freezing level rising to around 1000 m in the afternoon. Winds southwest 50 km/h becoming 80 km/h  in the afternoon/evening.Friday: Moderate snowfall. Strong to extreme southwest winds, freezing level up to 1300 m.

Avalanche Summary

There were reports of natural avalanches up to size 2.5 on north facing slopes during the weekend following loading from new snow and wind. Slope testing on Monday resulted in a few size 1 slabs in steep wind-loaded features.

Snowpack Summary

A new sun crust has formed on steeper solar aspects that may be buried by light snow. In shady areas there is 40-60 cm of well settled storm snow. Strong southwest winds formed touchy wind slabs in exposed terrain in lee of ridges, in gullies, and behind terrain features. There are a variety of old interfaces now down 60 - 100cm which include facets, crusts and isolated pockets of surface hoar. Recent observations indicate that these weaknesses have bonded fairly well now, but I still suggest digging and testing the snowpack to confirm.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 in northern and eastern parts of the region. Triggering the basal weakness may still be possible from thin spots, rocky outcrops or under the weight of larger triggers such as cornice fall.

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