Avalanche Forecast

Issued: Dec 19th, 2015 8:13AM

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.

Avalanche Canada triley, Avalanche Canada

Forecast new snow and wind will continue to add to the load of storm snow. Conservative terrain selection is recommended during the stormy weekend.

Summary

Confidence

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

Weather Forecast

10-15 cm of new snow is forecast overnight with strong southerly winds and freezing levels around 200 metres. Another 5-10 cm is forecast during the day Sunday with moderate westerly winds. The south of the region around Kitimat may see enhanced snowfall as the low pressure moves onshore in the central coast. Continued light snow on Monday with slightly higher freezing levels near 500 metres. Tuesday mostly flurries with cooler temperatures and a chance of broken skies.

Avalanche Summary

No new avalanches reported. Extensive wind effect reported in the alpine and at treeline.

Snowpack Summary

New snow continues to slowly build the load above buried weak layers. There is 15-25 cm above the December 17th (151217 SH) surface hoar, and 25-40 cm above the December 14th (151214 SH). At this time, the new snow continues to come in cold and dry and may not have the load needed to settle into a cohesive slab above these weak layers. The early December layer buried on the 1st or 2nd (151201 SH) is now down a metre or so depending on your area. This layers distribution is variable. In some areas, this layer may be sensitive to human triggering and wide propagations while in other areas it is non-existent or has gained significant strength. Most of this information is coming from the Shames area or from commercial operations near Terrace. Conditions may be different close to Kitimat, where it looks like recent snowfall amounts may be a bit higher and temperatures a bit warmer. The north of the region has a shallow early season snowpack and may have weak facetted crystals near the ground due to cold temperatures over a thin snowpack.

Problems

Storm Slabs

An icon showing Storm Slabs
Storm slabs continue to develop with each pulse of new snow and wind. Cool temperatures may be limiting slab development.
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

Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
No new reports of avalanches on this weak layer. Watch for continued loading above this weak layer at and near treeline. Low likelihood, but high consequence if you trigger this buried surface hoar.
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 20th, 2015 2:00PM