Avalanche forecast

Sea To Sky

Mar 23 – 24, 2016Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Forecast snowfall amounts for Wednesday night and Thursday are highly variable throughout the region. Pay close attention to how much snow falls in your area, and be prepared to back off to simple terrain.

Avalanche problems

  • 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.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–4
    Moderate to locally heavy snowfall and strong southwest winds are expected to form reactive new storm slabs on Wednesday night and Thursday morning. Watch for increased reactivity in high elevation leeward terrain.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

Moderate to locally heavy snowfall is forecast for Wednesday night. The Whistler area may see up to 15cm of new snow while double that amount may fall at the south end of Garibaldi Park and up the Squamish Valley. Generally light snowfall (up to 10cm) is forecast for Thursday; however, the convective nature of the weather pattern suggests spring "power flurries" may result in localized accumulations of up to 20cm. A dry ridge should develop on Friday bringing mainly clear skies while overcast conditions are expected on Saturday. Ridgetop winds should be moderate to strong from the southwest on Wednesday night and Thursday, and then become light for Friday and Saturday. Daytime freezing levels are forecast to sit at 1000m on Thursday, 1600m on Friday and 1400m on Saturday.

Avalanche Summary

On Tuesday natural loose wet avalanches to size 1.5 were reported to have occurred on variety of aspects and elevations. Forecast cooling should limit ongoing loose wet avalanche activity; however, a round of natural storm slab activity is expected on Thursday in response to new snow and strong southwest winds.

Snowpack Summary

Warm temperatures and the "greenhouse effect" from cloudy skies on Tuesday have promoted significant settlement within the recent storm snow. Dry settled powder can be found on high, north facing slopes while classic spring melt-freeze conditions exist on solar aspects above 2000m and all aspects at lower elevations. Potentially deep storm slabs are expected to form on Wednesday night and Thursday morning. Below the new snow the snowpack is strong and well-settled throughout with no notable persistent weaknesses. Cornices are huge and fragile.

Regions covered