Avalanche forecast

South Rockies

Feb 22 – 23, 2014Avalanche Canada
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Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Don't get powder hungry and let the improving weather lure you into high risk scenarios. Check out the South Rockies Blog! Conditions are tricky and primed for human triggered avalanches.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    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. All elevations are suspect and have been reactive.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    The storm slab may release naturally in the alpine where wind transport continues to add a new load. The storm slab is expected to continue to be very sensitive to human triggers at all elevations.

Confidence

Fair - Forecast snowfall amounts are uncertain on Sunday

Weather Forecast

The arctic high off the north coast will continue pushing southward into central BC and bring a cooler, dryer NW flow to the region. Some unstable disturbances are embedded in this flow, bringing scattered cloud and light precipitation on Sunday.Tonight/ Sunday: Cloudy with sunny periods and isolated flurries. Alpine temperatures near -23.0. Light NE ridgetop winds.Monday: Sunny with some cloud. Alpine temperatures near -13.0. Ridgetop winds light from the north.Tuesday: Sunny. Alpine temperatures near -7.0. Ridgetop winds blowing light from the north.

Avalanche Summary

On Saturday, we received a report of a snowmobile triggered a size 3 slab avalanche in the Coal Creek area (Notch). It sounds like 7 sledders were involved and all self rescued. The avalanche was on a North aspect and the crown was 1-2 m deep. On Friday, the SR field team witnessed several large snowmobile remote triggered slab avalanches in the Elk Valley North. These avalanches were all triggered below treeline around 1800 m. On Thursday, a natural size 2.5 avalanche occurred near the Coal Creek road. The debris just reached the road, didn't block it but the air blast covered the road with branches. Wind loading and sunshine are expected which may allow for an increase in natural avalanche activity. Conditions are primed for human triggered slab avalanches.Check out the South Rockies Blog to view photos of the remote triggered avalanches they witnessed on Friday. It displays how sensitive and reactive the persistent weak layer continue to be. Finding safe areas to ride, and choosing the most appropriate terrain is very tricky given the current conditions.

Snowpack Summary

The recent storm snow is up to a metre thick. This slab continues to settle and become more cohesive, overlying a complex medley of persistent weak layers (mainly facets and some surface hoar). This weak layer is below the storm slab and widespread on all aspects and at all elevations across the region. This is the classic firm slab over soft and weak layer that allows for wide propagations and remote triggering. This problem may persist for days after the storm or even weeks. Wind loading and sunshine may cause another natural avalanche cycle on this layer. The mid snowpack is strong and supportive. A 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.

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