Avalanche forecast

Sea To Sky

Mar 22 – 23, 2016Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
1 · Low
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Highlights

The Avalanche Danger is expected to rise throughout the day on Wednesday, and heavy accumulations are possible in the far south of the region. Pay close attention to how much snow falls in your area, and be prepared to back off to simple terrain.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–3
    New snow and strong winds forecast for Wednesday will promote new wind slab formation at treeline and in the alpine. New wind slabs are expected to increase in size and reactivity throughout the day.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–5
    Some cornices are the size of a bus, and will continue to grow with forecast snow and wind. Give these monsters a wide berth when traveling on or below ridge crests.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Wednesday

Weather Forecast

On Wednesday expect 10-25cm of new snow to fall throughout the day with strong southwest ridgetop winds. The highest accumulations are expected in the south of the region. Continued light flurries and decreased winds are forecast for Thursday, while clearing skies are forecast for Friday. Freezing levels should sit at 1400m on Wednesday, 1200m on Thursday, and 1600m on Friday.

Avalanche Summary

In recent days a few soft slabs to size 2 were observed failing within the new storm snow at treeline and in the alpine. Daytime warming and solar radiation also triggered loose wet avalanches to size 2.5 in steep sun-exposed terrain. Forecast cooling should limit ongoing loose wet avalanche activity; however, a round of natural wind slab activity is expected on Wednesday in response to new snow and strong southwest winds.

Snowpack Summary

On Sunday night the region received between 12 and 30cm of new snow with highest amounts falling in the Southern Garibaldi/ Brandywine parts of the region. Moderate southerly winds formed soft slabs which seemed most reactive in lee alpine terrain. Warm temperatures and the "greenhouse effect" from cloudy skies on Tuesday have surely promoted significant settlement within the recent snow The new accumulations overlie a sun crust on sun-exposed slopes, dry settled powder on shady slopes and moist snow below 1800m. Below the new snow the snowpack is strong and well-settled throughout with no notable persistent weaknesses. Cornices are huge and fragile.

Regions covered