Avalanche Forecast

Issued: Jan 2nd, 2014 9:57AM

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

Avalanche Canada slemieux, Avalanche Canada

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Friday:  The snow that started accumulating throughout the day should continue till the early hours of Friday. The expected total snow accumulation are looking to be around 15 cm. The strong W winds will switch from the NW. Freezing level will continue dropping during the day to hit valley bottom.Saturday:  A ridge of high pressure will dominate the weather pattern bringing clear and valley bottom freezing levels. Winds should calm down to become light.Sunday: Similar weather outlook as the previous day as the ridge will continue to hold over the province.

Avalanche Summary

Several natural loose and slab avalanches up to size 1.5 were reported yesterday in the alpine on S and E aspects in steep rocky terrain. There was also a couple skier triggered slabs size 1 reported in the NW part of the region. These would have initiated in a windslab in steep rocky alpine terrain. We expect more natural avalanche activity in the coming days with the storm passing through.

Snowpack Summary

The expected moderate snow accumulations, with the strong winds from the W and NW, is the reason the danger level is rising. The bond between the new storm snow at all elevation and new windslabs on E and SE in the alpine and at treeline with the old surface is likely to be poor and therefore, will need some time settle.  This new load could also awaken some deeper persistent weak layers situated between 50-70 cm in the snowpack which consists of surface hoar on sheltered slopes or crust/facets combo on steep solar aspects. If these deep persistent weak layers become reactive, very destructive avalanches could be triggered.

Problems

Storm Slabs

An icon showing Storm Slabs
Loading from new snow and strong W-NW winds is likely to cause avalanches, especially on exposed lee slopes.
Whumpfing, shooting cracks and recent avalanches are all strong indicators of unstable snowpack.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 4

Valid until: Jan 3rd, 2014 2:00PM

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