Avalanche Forecast

Issued: Jan 1st, 2012 8:19AM

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

triley, Avalanche Canada

South Rockies.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Tuesday

Weather Forecast

The winds are expected to build from the southwest on Monday, and moderate precipitation should start to accumulate snow by late afternoon. A trailing cold front is forecast for Tuesday. Snowfall amounts are un-certain and will depend on how much moisture is in the area when the cooler air arrives. Strong southwest winds and rising freezing levels are forecast for Wednesday. Models are showing the snow confined to near coastal areas, with only light amounts in the interior and South Rockies.

Avalanche Summary

Skiers remotely triggered a size 2.0 slide from 10 metres away, that was 60 cm deep, 70 metres wide, and 75 metres in length. Natural avalanche activity reported today was limited to a natural wind slab release size 2.5 from a North-East aspect. We continue to get reports of old activity that occurred during the recent storm.

Snowpack Summary

Tests in Hartly Creek on Saturday showed easy results down 20 cm on a layer of stellar crystals. Height of snow in the Koko Claims area is 120 cm at 200 metres. The mid-december surface hoar is down about 30 cm. The mid-pack is generally well consolidated, and there is a 20 cm layer of 4F facets and depth hoar at the ground. The surface hoar is producing easy to moderate shear test results.

Problems

Wind Slabs

Wind slabs can be found on North through Southeast aspects. Cross-loading is possible on open slopes oriented parallel to the wind. You may find wind slabs further down the slope or on open wind exposed areas below treeline.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 4

Persistent Slabs

Warm temperatures may consolidate the snow above the surface hoar into a slab that may propagate wide avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 5

Valid until: Jan 2nd, 2012 8:00AM