Avalanche Forecast

Issued: Dec 21st, 2015 8:04AM

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

esharp, Avalanche Canada

Northwest Coastal.

Variable winds will drive avalanche conditions in the coming days. The best riding conditions can be found in sheltered areas, but be mindful of the layer of surface hoar buried at tree-line

Summary

Confidence

Moderate

Weather Forecast

Were entering into a period of fairly benign weather. Light snow with accumulations of around 5cm are expected for coastal regions with only isolated flurries forecast inland of Terrace overnight and into Tuesday. Winds look to variable, coming from the west on Tuesday, becoming south easterly on Wednesday, and returning to the west on Thursday. Freezing levels are expected to remain around 500m for coastal regions and at or close to valley bottom for inland regions through the forecast period.

Avalanche Summary

Several small naturals were reported from steep rock slabs at low elevations above the highway. No new avalanche reported from higher elevations although I suspect that travel and visibility may have been restricted by stormy conditions.

Snowpack Summary

The recent storm brought 20 cm of new snow to Shames, with slightly more further west. The north of the region around the east end of the Bear Pass received up to 40cm. Soft storm slabs are developing, especially in wind loaded features, and cornices are forming at ridge-top. The new snow continues to add load to several buried weak layers. There is now 25-40 cm above the December 17th surface hoar, and 35-55 cm above the December 14th surface hoar. The December 1st surface hoar is now down a meter or so depending on your area. The distribution of this layer is variable. In some areas, it may still be sensitive to human triggering and capable of wide propagations. In other areas it is non-existent or has gained significant strength. Conditions may be different close to Kitimat, where it looks like recent snowfall amounts may be a bit higher and temperatures a bit warmer

Problems

Storm Slabs

Storm snow amounts vary across the region. Deep pockets of wind transported snow may exist on northeast through northwest aspects at higher elevations.

Stay well to the windward side of corniced ridges.>Travel on ridgetops to avoid wind slabs on slopes below.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

A deeply buried weak layer of surface hoar should be on your radar. I would be suspect of steep unsupported slopes at tree-line unless I knew the layer did not exist or was now well bonded.

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.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Dec 22nd, 2015 2:00PM