Avalanche Forecast

Issued: Dec 12th, 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.

Conditions below treeline vary greatly. Many areas are still below the threshold for avalanches, but buried surface hoar may be present as you gain elevation.

Summary

Confidence

Moderate

Weather Forecast

On Sunday, expect mainly cloudy skies and light northwest winds. By late Monday and Tuesday, the region could see up to 15cm of new snow and strong southwest winds. The freezing level should hover around valley bottom for the entire forecast period.

Avalanche Summary

In recent days, explosives avalanche control in the north of the region produced a few wind slab avalanches to size 2. No other 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. Low-elevation slopes below treeline may still be bellow threshold for avalanches in many places.

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.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Wind Slabs

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

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 13th, 2015 2:00PM