Avalanche Forecast

Issued: Dec 16th, 2017 5:24PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs.

Avalanche Canada mgrist, Avalanche Canada

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South Coast Inland.

Fresh storm slabs may bond poorly to a melt-freeze crust on Sunday. If you see more than 30cm new snow on a firm crust, consider the danger to be HIGH.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Sunday

Weather Forecast

Significant storm snow totals are forecast for the south of the region (Coquihalla area), with lesser amounts in the north. SUNDAY: Snow. Accumulation 5-20 cm (highest amounts for Coquihalla area). Ridge winds moderate from the southwest. Temperature -2. Freezing level 700 m.MONDAY: Flurries. Accumulation 5-10 cm (highest amounts for Coquihalla area). Ridge winds moderate from the west. Temperature -4. Freezing level 700 m.TUESDAY: Snow. Accumulation 10-20 cm. Ridge winds moderate from the north. Temperature -4. Freezing level 700 m.

Avalanche Summary

Small natural dry loose avalanches to Size 1 were reported in the north of the region (Duffey Lake zone) on Saturday.

Snowpack Summary

About 10cm of new snow covers a crust that formed on almost all aspects: the exception being shaded north aspects at upper elevations, where the old snow surface consisted of dry, sugary snow.Lower down, the snowpack is well settled and overlies the late November rain crust, now 20-50 cm deep. Snowpack tests in the Duffey Lake area produced hard, sudden test results associated with this layer. Treeline snow depths are approximately 1 m throughout the region.

Problems

Storm Slabs

An icon showing Storm Slabs
Take a cautious approach to the mountains on Sunday, especially if you see more than 20cm of new snow on a firm crust.
Watch for signs of instability such as whumpfing, shooting cracks or recent natural avalanches.Minimize overhead exposure during periods of heavy loading from new snow and wind.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Valid until: Dec 17th, 2017 2:00PM

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