Avalanche forecast

South Rockies

Feb 26 – 27, 2014Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Wind has transported snow and built fresh, touchy wind slabs on the leeward side of terrain features. Be aware of weak cornices looming over slopes. If they fail, it could trigger large slab avalanche on the slope below.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    3–6
    The persistent weak layer continues to be very sensitive to any additional load. Remote triggering from adjacent terrain and very long fracture propagations are a major concern on all aspects and elevations.

Confidence

Fair

Weather Forecast

High pressure conditions are expected for Thursday before a weak system from the southwest affects the region Thursday night and Friday. On Friday night, cold arctic air will push into the region and will dominate on Saturday.Thursday: A mix of sun and cloud, temperature inversion conditions, ridgetop winds 20-30 W-NWThurs. night/Friday: Mostly cloudy, snow flurries 4-8cm, treeline temperature around -12C, ridgetop winds 10-20 W-NWSaturday: Mostly sunny, treeline temperature around -20C, ridgetop winds 20-30 NE-E

Avalanche Summary

On Tuesday, we received reports of several natural size 1 loose dry avalanches from steeper terrain features, most likely triggered by the sun. Also reported was a size 2 wind slab triggered by explosives near Fernie. Check out the South Rockies Blog for recent photos and insights of what people are seeing out there.

Snowpack Summary

Large cornices loom on ridgelines and threaten the slopes below. Variable winds have transported some of the recent storm snow, building new wind slabs on leeward slopes. A persistent slab 80-120 cm thick sits on a weak interface comprising of facets and a crust. It continues to show sudden planar shears at the interface, and a high degree of sensitivity to human triggers. Wide propagations and remote triggering remain a concern. With forecast sunny periods, solar aspects may see moist snow surfaces which will then form a crust overnight. The deep persistent layer of facets and depth hoar near the base of the snowpack has remained dormant to this point, but may become a concern with additional load and stress on the snowpack like a cornice fall or large avalanche.

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