Avalanche Forecast

Issued: Dec 23rd, 2016 5:56PM

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

Avalanche Canada cgarritty, Avalanche Canada

Recent storms have set up great skiing and riding for the holiday weekend, but don't overlook the wind slab problem that still exists at upper elevations.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

Saturday: A mix of sun and cloud with no new snow. Winds light from the northeast. Alpine temperatures from -6 in the south of the region to -11 in the north.Sunday: A mix of sun and cloud with no new snow. Winds light from the southwest. Alpine temperatures to -9.Monday: Snow accumulating up to 25cm in the south of the region, 10cm in the south. Winds moderate to strong from the southwest. Alpine temperatures around -5.

Avalanche Summary

While recent reports point only to new snow sluffing easily in steep terrain, the Duffey Lake area saw a few natural avalanches running to size 2 in the alpine as recently as Tuesday. Continued potential exists for skier and rider triggering of wind slabs at upper elevations. The possibility of buried surface hoar in isolated sheltered areas.and a possible weak bond at the storm/old snow interface also demand careful evaluation.

Snowpack Summary

10-15cm of new snow fell on Thursday, adding to the 30-60cm of storm snow the region has seen since Sunday. In higher elevation and exposed areas, the storm snow formed wind slabs in response to southwest winds. The new snow and wind slabs overlie a variable snow surface from last week that includes hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or surface hoar. In the Duffey Lake area, recent snowpack tests gave hard sudden results down 60 cm at the interface between the recent storm snow and old snow on rounding faceted crystals. The widespread mid-November crust is typically down approximately 1-1.5m. Recent snowpack tests have shown the crust to be unreactive, but it could become a problem in shallow alpine start zones.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs remain a problem to be managed with ongoing observation and careful evaluation. A thin layer of new snow may be masking buried wind slabs.
Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.Watch for signs of instability such as whumpfing, or cracking.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 24th, 2016 2:00PM

Login