Avalanche Forecast

Issued: Jan 5th, 2018 4:17PM

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

mconlan, Avalanche Canada

Cariboos.

A weak layer is buried at a depth prime to human triggering, particularly in the south of the region. As the overlying snow forms a slab from new snowfall and warmer air, destructive avalanches will likely result. Cautious route finding is advised.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

SATURDAY: Mostly cloudy with light flurries, accumulation 5-10 cm, light to moderate southwesterly winds, freezing level near valley bottom.SUNDAY: Cloudy with light flurries, accumulation 1 to 3 cm, light to moderate southwesterly winds, freezing level near valley bottom.MONDAY: Cloudy with light flurries, accumulation 5-10 cm, light southwesterly winds, freezing level near 1000 m.

Avalanche Summary

Numerous small loose avalanches have been reported in the region over the past few days. Slab avalanches are becoming more likely as the upper snowpack begins to settle with warm temperatures and forecasted new snow.

Snowpack Summary

A warming trend and additional snow could create a dangerous slab above buried weak layers. Numerous persistent weak layers exist in the snowpack. Dry snow overlies two layers composed of weak and feathery surface hoar, with the deeper layer (December 15) buried 30 to 60 cm. This layer is shallower in the north of the region and deeper in the south of the region. The weak layer is found most often at treeline and below treeline. If the dry snow becomes more cohesive and forms a slab, this layer has the potential to create easily-triggerable destructive slab avalanches.The new snow is falling on variable surfaces, including surface hoar in sheltered slopes, a sun crust on steep solar aspects, and wind effect in exposed alpine and treeline locations.Deeper in the snowpack at depths of about 70 to 100 cm, a rain crust from November is producing variable snowpack test results, from sudden fracture characters to no result. This layer is considered dormant for now, but could be triggered where the snowpack is thin.If you have any recent observations, please share them through the Mountain Information Network.

Problems

Persistent Slabs

Around 30 to 60 cm of snow sits above a touchy weak layer. As this snow settles and gains slab properties, a dangerous slab that is easily triggered will likely form.

Use conservative route selection. Choose moderate-angled and well-supported terrain.Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

New snow will likely move easily, as it is falling on a recently buried weak layer and/or a crust.

Avoid exposure to terrain traps where the consequence of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 6th, 2018 2:00PM