Avalanche forecast

Purcells

Apr 8 – 9, 2013Avalanche Canada
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Archived · expired 13 years ago

Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–5
    Wind slabs are a problem on high elevation lee slopes. The large cornices that loom over many slopes have the potential to fail and trigger avalanches.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    In some areas, new snow is bonding poorly to a weak interface buried below. Skiers have been triggering slabs remotely, from up to 60 m away.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Watch for loose wet avalanches and glide slabs, which may fail naturally in response to rainfall at low elevations.

Confidence

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

Weather Forecast

Tuesday: Light snow. Light NW winds. Alpine temperature near -6. Wednesday: 10-20 cm snow. Strong SW winds. Alpine temperature near -4.Thursday: Light snow. Light SW winds. Alpine temperature near -5.

Avalanche Summary

An avalanche cycle of slabs up to size 3 occurred during the weekend’s storm. Many of these events were on NE-NW (wind-loaded) aspects above about 2400 m. Several size 2 skier-remote triggered slabs were also reported on Sunday. These failed on surface hoar buried below the storm snow. They occurred on W-NE aspects above 2500 m.

Snowpack Summary

Recent storm snow (up to 40 cm) is sitting on a variable interface, consisting of a crust or moist snow; or a recently formed layer of surface hoar or facets, which is mainly found on high-elevation W through NE aspects. In some locations the surface hoar/facet interface is touchy, with skier triggering likely. Winds have shifted storm snow into reactive slabs lee to south-easterly to south-westerly winds. Below treeline, the snow is in a spring melt-freeze regime, melting by day and freezing by night. Cornices are very large and loom as potential triggers for avalanches.

Regions covered