Avalanche forecast

Northwest Coastal

Dec 2 – 3, 2017Avalanche Canada
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Avalanche danger

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

The recent storm snow will need time to settle and may be reactive to rider triggers. Storm slab avalanches could step down and trigger deeper layers within the snowpack, initiating large avalanches.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Storm slabs may be reactive to rider triggers, especially at upper elevations where the storm snow has been affected by wind.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–4
    A lot of uncertainty exists around the reactivity of this layer near the base of the snowpack. A conservative approach to terrain is warranted while the snowpack adjusts to the recent load of storm snow and wind loading.

Confidence

Low - Due to the number and quality of field observations

Weather Forecast

Sunday: Mix of sun and cloud. Ridgetop winds light from the North West. Alpine temperatures near -6 and freezing levels 500 m. Monday: Mostly cloudy with up to 10 mm precipitation. Alpine temperatures near 0 degrees and freezing levels rising from 800-1500 m. Ridgetop winds strong from the South West.Tuesday: Mostly cloudy with light precipitation. Alpine temperatures near 0 degrees and freezing levels 1500 m. Ridgetop winds light from the South West.Check out the Mountain Weather Forecast for details.

Avalanche Summary

Considering the amount of new storm snow there has been no recent avalanche activity reported. I remain suspect of the new snow and the bond to the buried crusts, especially the basal crust. I would be diligent and use a conservative approach to route selection while traveling through low consequence terrain. The new storm snow will need more time to settle and adjust to the layers beneath. Storm slabs may be reactive to rider triggers. Check out the Mountain Information Network for recently posted observations around the Shames area. Give info, get info.

Snowpack Summary

Recent accumulated storm snow amounts are from 100-130 cm and seem to be settling quickly with average snowpack depths 100-150 cm at treeline elevations. Deeper deposits of wind slab may be found on leeward slopes. This storm snow now sits above a 5-10 cm thick crust that was buried a week ago. Digging down 90-160 cm exists a crust/facet combo buried at the end of October. Recent snowpack test results are showing hard compression tests with sudden collapse results. I would keep this on my radar through the weekend to see how the snowpack adjusts to the new load.

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