Avalanche forecast

South Coast Inland

Dec 21, 2017Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

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

The recent storm snow will take some time to settle and stabilize. Until then make conservative terrain choices and watch for additional loading from wind on leeward areas.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    Tuesday's storm brought heavy snowfall to the southern part of the region with moderate to strong (north) westerly winds. Give things time to settle out and stick to simple terrain with no consequence or overhead hazard.

Confidence

Moderate - The weather pattern is stable

Weather Forecast

THURSDAY: Cloudy, flurries. Accumulation up to 5 cm. Ridge wind moderate to strong from the west. Temperature -4. Freezing level 400 m.FRIDAY: Mix of sun and cloud, light flurries. Accumulation trace. Ridge wind light from northeast. Temperature -8. Freezing level 200 m.SATURDAY: Mainly sunny. Ridge wind light from the northeast. Temperature -10. Freezing level surface.

Avalanche Summary

The Coquihalla and Allison Pass areas reported numerous loose dry to Size 1.5, as well as slab and glide avalanches to Size 2 on steep, leeward terrain and smooth rock slabs on Wednesday.On Tuesday the northern part of the region saw several skier controlled avalanches to Size 1 in both hard and soft wind slabs at treeline as well as significant wind loading (up to 60 cm) and cracking on open slopes.In the southern part of the region no new avalanches have been observed, however classic signs of instability such as whumpfing and shooting cracks have been reported here in the MIN.

Snowpack Summary

The southern part of the region has seen impressive storm snow totals (80-100cm) since Sunday night, compared to the north of the region, which received 25-35cm. This new snow sits on crusts of variable thickness that formed on almost all aspects in mid-December (December 15th layer). On steep southerly aspects the crust is supportive, whereas on northerly aspects the crust is quite thin and variable. Beneath the December 15th layer the snowpack is well settled and has not been showing any signs of activity on the late November rain crust which is now buried 40-50 cm in the northern part of the region and closer to 1 m in the south. Treeline snow depths are approximately 1.4 m throughout the region.

Regions covered