Avalanche forecast

South Coast

Jan 31 – Feb 1, 2016Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Destructive persistent weak layers should still be on your radar if you're heading to the north of the region.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    Triggering fresh soft wind slabs is possible in exposed lee terrain near ridge crests, especially on steep unsupported slopes. 

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    3–6
    Buried persistent weaknesses may have been destroyed in most areas, but remain cautious in high elevation terrain (particularly in the north of the region) where this problem may be lingering.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2
    Cold dry snow could sluff easily in steep terrain. Additionally, loose wet sluffs are possible on steep sun-exposed slopes if the sun pokes out. 

Confidence

Moderate

Weather Forecast

Monday: Cloudy with flurries and clearing in the afternoon. The freezing level is around 500-700 m and winds are light from the SW. Tuesday: A mix of sun and cloud. The freezing level remains near 500 m and winds are light and variable. Wednesday: Periods of snow. The freezing level is around 800-1000 m and winds are moderate from the S-SE.

Avalanche Summary

There were no new reports of avalanches in the northern part of the region on Saturday. In the Coquihalla, where there was much more snow on Friday, there were reports of several soft storm slabs up to size 2 that were failing within the fresh storm snow. On Thursday, slab avalanches to size 3.5 were observed on a variety of aspects and elevations. These occurred in response to heavy storm loading from rain and snow. The mid-January surface hoar was the suspected culprit in many of these avalanches. Of note was a size 4 slab avalanche in Steep Creek in the Duffey Lake area.

Snowpack Summary

In the south, 40-70 cm of recent storm snow sits on a widespread and generally supportive rain crust that was buried on Jan. 28. The bond to the crust appears to be fairly good but at least one notable storm snow weakness was observed 10 cm above the crust. Fresh pockets of wind slab may also form in immediate lee features. The combination of heavy storm loading, rain, and warm temperatures likely flushed out the mid-January persistent weakness in most areas in the Cascades. Further north, generally 20-40 cm of dry storm snow overlies the late-Jan rain crust below around 1800-2000 m. Above this elevation the new snow sits on settled storm snow or previously wind affected surfaces. Fresh pockets of wind slab are likely in exposed lee terrain. Where it still exists, the mid-January surface hoar layer is between 60 and 130 cm below the surface. This persistent weakness could be lingering on higher elevation slopes that did not previously avalanche and triggering remains a concern.

Regions covered