Avalanche Forecast

Issued: Dec 19th, 2016 4:25PM

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

Avalanche Canada jlammers, Avalanche Canada

I'd give the new snow a few days to settle and gain strength before pushing into any steep terrain. A freshly buried weak layer may prolong the reactivity of newly developed slabs.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Tuesday: 8-15cm of new snow / Strong to extreme west winds / Freezing level at 1200mWednesday: Mix of sun and cloud with light flurries / Moderate southwest winds / Freezing level at 1100mThursday: Mix of sun and clouds / Moderate southwest winds / Freezing level at 1000m

Avalanche Summary

On Sunday, several size 1 wind slabs were ski cut in the Lizard Range. On Monday, new snowfall and strong winds are expected to have produced a solid round of wind slab activity at all elevation bands, although no formal updates from the field were available at the time of producing this bulletin . The new snow buries a weak interface which will likely prolong the reactivity of new slabs.

Snowpack Summary

By Monday afternoon, up to 45cm of low-density snow had fallen with the highest amounts accumulating in the Lizard Range. Intense wind transport was reported to have occurred at all elevations, and reactive wind slabs are expected to exist. The new snow buries a variable surface that developed over the last week of cold, dry, and windy conditions. This interface consists of scoured surfaces and wind slabs in wind exposed terrain, widespread faceting of the upper snowpack, and surface hoar up to 20 mm in sheltered areas. In sheltered areas, you may find another layer of surface hoar in the mid to upper snowpack which was buried around December 10. The mid pack is generally well settled. The thick crust from mid-November is near the bottom of the snowpack and reports suggest that the crust is currently well bonded to the surrounding snow.

Problems

Wind Slabs

An icon showing Wind Slabs
New snowfall and  winds have formed fresh wind slabs in exposed terrain. More snowfall on Tuesday will increase the size and reactivity of these slabs Where the new snow is unconsolidated, loose dry avalanches remain a concern in steep terrain.
Avoid freshly wind loaded features.Use ridges or ribs to avoid pockets of wind loaded snow.Avoid slopes where the snow feels stiff or slabby.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Valid until: Dec 20th, 2016 2:00PM