Avalanche forecast

Sea To Sky

Jan 20, 2018Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

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

Recent snow and wind have formed storm slabs that will continue to build with more snow and wind forecasted for the weekend. Carefully monitor how the new snow is bonding and watch for freshly wind-loaded areas.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2.5
    Recent storm snow and strong southerly winds has formed cohesive storm slabs particularly at upper treeline and alpine elevations. These slabs overlie a recent melt-freeze crust and will continue to build with more snow and wind in the forecast.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

Upper range snowfall amounts are expected for areas in the southern part of the region.TONIGHT: Snow. Accumulation 5-10 cm. Ridge wind moderate, southwest. Temperature -5. Freezing level 800 m.SATURDAY: Snow. Accumulation 15-30 cm. Ridge wind moderate, southwest. Temperature -4. Freezing level 900 m.SUNDAY: Snow. Accumulation 20-40 cm. Ridge wind strong, southwest. Temperature -4. Freezing level 900 m.MONDAY: Flurries. Accumulation 5-15 cm. Ridge wind moderate, southwest. Temperature -5. Freezing level 800 m.

Avalanche Summary

Explosive control work on Friday produced only a few size 1 and isolated size 2 avalanches failing in the recent storm snow or running on the recently buried January 15th crust. On Thursday there were reports of natural avalanches up to size 2.5, while ski cuts and explosive control work produced numerous size 1-1.5, and up to size 2, storm slab avalanches 20-50 cm deep on predominantly northerly aspect, running far and wide within the recent storm snow.Wednesday ski cutting and explosive control work produced numerous easily triggered size 1 storm slab results up to 40 cm deep running on the January 15th crust. And on Tuesday, explosive control work and ski cutting produced numerous size 1-1.5 storm slab releases on leeward aspects at treeline and into the alpine, running on the January 15th crust.

Snowpack Summary

Above 1400 m elevation, 50-70 cm of storm snow overlies the January 15th crust which is present at all elevations. This crust is thin on northerly aspects and up to 3 cm thick on solar aspects. Below this crust 30-40 cm of moist, well settled snow overlies the January 6th crust which is now buried about 100 cm below the surface and exists up to about 2000m. Beneath the January 6th crust, the lower snowpack is generally strong and well settled.

Regions covered