Avalanche forecast

South Coast Inland

Feb 23, 2018Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

Sat
Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

New snowfall may not bond well to underlying snow surfaces. Expect old and new wind slabs on all aspects at higher elevations, loose dry snow in sheltered areas, and looming cornices on ridgelines.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2.5
    New snow with strong southwesterly wind will produce fresh wind slabs in lee features.  These sit on wind slabs formed during last weekend’s storm. Watch for signs of avalanche activity and locally unstable snow.
  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    Large cornices linger along ridgelines. They are unstable, unpredictable, and demand respect.

Avalanche Summary

No new avalanche observations were noted on Wednesday.  On Tuesday, several natural loose dry avalanches up to size 1 were reported from steep south facing rocky terrain.Wind slabs are becoming more stubborn to trigger but remain the primary avalanche concern for the region. Respect overhead hazards, such as cornices.

Weather Forecast

FRIDAY: Cloudy with snowfall, accumulation 5 to 15 cm, strong southwesterly winds, alpine temperature -12 C, freezing level below valley bottom.SATURDAY: Cloudy with early-morning snowfall then clearing to partly cloudy, accumulation 5 to 10 cm, light northwesterly winds, alpine temperature -10 C, freezing level near 500 m.SUNDAY: Cloudy with early-morning snowfall, accumulation 5 to 15 cm, moderate to strong westerly winds, alpine temperature -7 C, freezing level near 700 m.

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Snowpack Summary

New storm snow will fall on highly variable and wind-affected snow surfaces. In exposed terrain, new snow will fall on scoured north facing slopes and wind-loaded south facing slopes. In sheltered terrain, new snow will fall on last weekend’s storm snow. The new snow may not bond well to these surfaces and could be reactive to both natural and human triggers.Deeper in the snowpack in southern parts of the region, recent snow sits above a widespread crust.  Below the crust, well-consolidated snow exists.Avalanche professionals are still monitoring the mid-January crust and are avoiding shallow rocky slopes where triggering this layer is most likely. This layer is now 80-150 cm deep, but a heavy trigger (such as a cornice fall) or the next major storm (loading and/or warming) could wake this layer up.

Regions covered