Avalanche forecast

Purcells

Mar 2 – 3, 2014Avalanche Canada
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Archived · expired 13 years ago

Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Moderate to strong winds are expected to blow new accumulations into pockets of wind slab in exposed lee terrain. These new accumulations will overlie existing thin wind slabs which have been reactive in recent days.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–5
    A deep and destructive slab overlies a variety of weak layers and rider triggering continues throughout the region. Conservative terrain selection is critical to safe mountain travel.

Avalanche Summary

In the Dogtooth Range on Friday, skiers initiated a cornice fall which triggered a size 2.5 slab avalanche on the slope below. In the same area on Saturday a size 2 slab was rider triggered from a ridge crest. A size 2 natural slab avalanche was observed on Saturday further south in the region. The February 10th interface is thought to have been the culprit in all of these events.

Weather Forecast

Monday: Light to locally moderate snowfall / Moderate to strong southerly winds / Freezing level at 1200mTuesday: Light to locally moderate snowfall / Moderate to strong southwest winds with extreme gusts / Freezing level at 1200mWednesday: Mix of sun and cloud with a possibility of flurries / Light ridgetop winds / Freezing level at 800m

Confidence

Fair - Forecast snowfall amounts are uncertain on Monday

Snowpack Summary

Light amounts of new snow are expected to overlie weak surface hoar in sheltered areas, a sun crust on solar aspects and thin wind slabs in exposed terrain. These new accumulations are likely to be reactive as a wind slab in pockets of exposed terrain.The big news remains a mix of weak surfaces which were buried on February 10th. This persistent interface lies between 50 and 120cm below the surface, and includes surface hoar, well developed facets and a mix of hard surfaces which remain widespread at all aspects and elevations. Although natural avalanche activity has tapered-off at this interface, destructive avalanches are still a very real concern with ongoing reports of human triggering, whumpfing and sudden/easy snowpack test results. The mid and lower snowpack are generally strong and well consolidated. Weak basal facets exist in many areas, but triggering has now become unlikely.

Regions covered