Avalanche Forecast

Issued: Dec 13th, 2015 8:53AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs and Wind Slabs.

jlammers, Avalanche Canada

Northwest Coastal.

Significant variability exists in the top 100cm of the snowpack. Dig down and test for weak layers before committing to any steep or exposed lines.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Expect a mix of sun and cloud and moderate northwesterly winds on Monday. On Monday afternoon and Tuesday, a Pacific front will bring up to 15cm of snow and strong westerly winds. Generally clear skies and moderate northeasterly winds are forecast for Wednesday. Freezing levels may rise to 500m with the passage of the front. Otherwise, they should remain around valley bottom for the forecast period. For a more detailed weather overview, check-out our Mountain Weather Forecast at: avalanche.ca/weather

Avalanche Summary

No new avalanches have been reported.

Snowpack Summary

Up to a meter of settled snow may be sitting upon a weak layer of buried surface hoar. In some areas, this layer may be primed for human triggering and wide propagations while in other areas it is non-existent or has gained significant strength. Due to the variable nature of this weak layer, I'd dig down to test for it before committing to any steep lines. I'd also be increasingly cautious on sheltered slopes at or below treeline.Strong north through easterly winds have been responsible for a recent reverse-loading pattern, and wind slabs may still be sensitive to human triggering on lee features.

Problems

Persistent Slabs

Human triggered avalanches on a layer of buried surface hoar have become less likely. However, avalanches at this interface could be destructive in nature. Dig down and test for this weakness before committing to any steep lines.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Wind Slabs

Moderate to strong winds have created wind slabs at treeline and in the alpine. Watch for triggering in gullies and in the lee of ridge crests.

Avoid travelling in areas that have been reverse loaded by winds.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 14th, 2015 2:00PM