Avalanche forecast

Sea To Sky

Mar 6 – 7, 2016Avalanche Canada
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Archived · expired 11 years ago

Avalanche danger

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

Give the new storm snow time to settle and strengthen before tackling big objectives.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–4
    Cornices are reported to be huge and weak. Stay well back from ridgecrests, and watch your overhead hazard.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    The storm has ended, but recently formed storm slabs may remain sensitive to light inputs. I'd remain cautious of wind-loaded terrain at treeline and in the alpine. If the sun comes out on Monday, loose wet avalanches may also occur on solar aspects.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Sunday

Weather Forecast

Up to 10cm of new snow and moderate to strong southwest winds are forecast Saturday night. For the rest of the forecast period expect to see a mix of sun and cloud, isolated flurries and generally light ridgetop winds. The freezing level is expected to hover between 1000m and 1200m. The next storm is forecast to hit the region on Wednesday night.

Avalanche Summary

On Saturday there was evidence of widespread natural storm slab avalanche activity to size 3.5. The avalanches failed in response to heavy storm loading on Friday and possibly warming on Saturday. I'm sure there was also another round of smaller storm slab avalanche activity on Sunday, although at the time of publishing observations were extremely limited.

Snowpack Summary

On Sunday 10-20cm of snow fell adding to the impressive amounts that had already fallen on Friday (up to 50cm in 24 hours). Storm totals from the past week were well over 100cm. Strong southwesterly winds have shifted the new snow into deeper storm slabs on lee and cross-loaded alpine and treeline features. On all but higher elevation shaded slopes the new snow from Sunday likely overlies a melt-freeze crust from high freezing levels and sun on Saturday afternoon. Ongoing stormy weather has also encouraged extensive cornice growth. Weaknesses below the recent storm snow are expected to have gained considerable strength while the mid and lower snowpack are also strong and well-settled.

Regions covered