Avalanche forecast

South Coast

Feb 19 – 20, 2018Avalanche Canada
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Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate

Highlights

Triggering an avalanche remains is a concern at all elevations. Be very suspect around wind-affected slopes and convex terrain features.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Strong northerly winds have formed fresh slabs at higher elevations.
  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2
    Large cornices have formed along ridgelines. Cornices are inherently unstable, unpredictable, and demand respect.
  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Triggering a slab above the buried crust remains a possibility at lower elevations.

Snowpack Summary

In exposed terrain, strong north winds have scoured north facing slopes and loaded south facing slopes. In sheltered terrain, cold weather is preserving 30-50 cm of low density snow. A hard rain crust that extends into alpine terrain is buried about 40 cm beneath the recent storm snow. Reports suggest the snow has a poor bond to the crust, meaning there's a potential for slab avalanches on any steep or convex terrain feature. Monitor the bond of the snow to this crust closely. There are no significant layers of concern below the crust.

Confidence

Moderate - Due to the number and quality of field observations

Weather Forecast

TUESDAY: Sunny, light north wind, alpine high temperatures around -10 C.WEDNESDAY: Mix of sun and cloud with isolated flurries, moderate north wind, alpine high temperatures around -7 C. THURSDAY: Mostly sunny, moderate north wind, alpine high temperatures around -5 C.

Avalanche Summary

No new avalanches were reported on Sunday, but whumpfing in flat terrain (a sign of instability) was reported in the North Shore mountains. Storm snow was very reactive on Saturday. There were numerous size 1-2 slab avalanches triggered by skiers on all aspects at treeline and below treeline elevations, including some that were triggered remotely (from a distance).Looking ahead, avalanche activity is most likely in areas that have been loaded by the recent northerly winds, but any steep terrain feature is suspect given the widespread crust sitting beneath the storm snow.

Regions covered