Avalanche forecast

Sea To Sky

Mar 28 – 29, 2017Avalanche Canada
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Avalanche danger

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

Snow fall amounts are uncertain on Wednesday; watch for developing hazard during the day.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–3
    The forecast storm is expected to continue to develop new cornice growth. While cornices are a hazard in themselves, the danger increases when they have the potential to act as a trigger to slabs sitting beneath them.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    New storm slabs are expected to develop overnight and during the day on Wednesday. Precipitation amounts are uncertain; watch for developing hazard during the day.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Wednesday

Weather Forecast

WEDNESDAY: Periods of snow, accumulation 15-20cm Tuesday night through Wednesday / Moderate southwest wind / Alpine temperature -2 / Freezing level 1400 m THURSDAY: Cloudy with sunny periods / Light northwest wind / Alpine temperature -3 / Freezing level 1600mFRIDAY: Cloudy with isolated flurries / Light to moderate southwest wind / Alpine temperature -2 / Freezing level 1200

Avalanche Summary

Reports from Tuesday indicate explosive and skier controlled avalanches to size 2 and 2.5. These were mostly wind and storm slabs failing 10-40cm deep. Some were also triggered by cornices pulling out 20-30cm slabs on slopes below.

Snowpack Summary

Continued light to moderate snowfall is expected to add to the recent storm slabs. 2000m and below, the storm snow lies above a crust that formed last week. A rain crust that was buried around March 15 is now 80-100 cm deep. The mid-February crust/facet layer can still be found at the upper end of tree line and into the alpine. This interface is generally 120-170 cm deep but may be present nearer to the surface in wind scoured areas. Although there is growing confidence that this layer is becoming dormant, a storm slab or cornice release in the right location may have the potential to trigger any of the deeply buried weak layers.

Regions covered