Avalanche Forecast

Issued: Dec 24th, 2011 9:23AM

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

mpeter, Avalanche Canada

South Columbia.

Check the forecaster blog for more info on the current conditions.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Sunday: Expect flurries to taper early in the day, giving way to mixed skies. As skies lift, expect winds to pick up, but remain southwesterly. More flurries could develop late in the day with freezing levels reaching 800m. Monday & Tuesday: More weak disturbances will move through the region, giving mixed skies and localized flurries. Southwest winds persist. Freezing levels will slowly rise and could reach 1500m by the end of the period.

Avalanche Summary

We have reports of several human triggered avalanches up to size 2.0 from the northern part of the region. These are running on the early December interface, predominantly on shady aspects between 1600-2100m.

Snowpack Summary

Up to 15cm of new snow has fallen in the past 24hrs. This overlies soft slabs on North through East aspects and some spotty, small surface hoar/surface facets in sheltered locations at treeline and below. This brings the total load over the early December surface hoar to 30cm in the South and 65cm in the North. This surface hoar layer is still producing sudden results in stability tests and a whole block rutchblock 4 was also observed. This is certainly the layer to watch; check out the forecaster blog for more info/ideas on this current problem. The midpack is well consolidated and strong.

Problems

Wind Slabs

Consistent westerly winds have lee loaded open terrain at treeline and in the alpine.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

Right now this is more of a concern in the northwest corner of the region. As more snow falls, this problem will increase across the rest of the region. Most pronounced on sheltered, shady aspects (i.e. large, open glades facing north and east).

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 4

Valid until: Dec 25th, 2011 8:00AM