Avalanche Forecast

Issued: Dec 31st, 2011 9:58AM

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

Avalanche Canada ghelgeson, Avalanche Canada



Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

A ridge of high pressure drifts into the area Saturday evening driving overnight temperatures into the mid minus teens. On Sunday morning high clouds steam into the region ahead of the approaching mass of warm air. Light precipitation should begin after lunch, but I'm only expecting 5 - 10cm max for the day. The bigger story with the warm front is the rise in freezing levels which could go as high as 1500 m. Winds build to moderate/strong values out of the SW Sunday. A weak cold front affects the area Monday afternoon bringing another shot of light precipitation & lowering temps/freezing levels.

Avalanche Summary

Numerous avalanches from size 1 - 2 have been observed at all 3 elevation bands (BTL, TL, ALP), with failures occurring within the recent storm snow in the last 72 hours. Interesting to note that a size 3 was observed below treeline in the region Thursday, I suspect the mid December Surface Hoar was to blame.

Snowpack Summary

70-100 cm of total storm snow has fallen since Christmas. Winds have redistributed the storm snow into wind slabs that are widespread in the alpine. Wind slabs can also be found in wind exposed areas at and below treeline. The mid December surface hoar/facet/crust interface is buried anywhere from 80-100cm deep and remains a concern for backcountry users. Avalanche activity on this layer has slowed, but it remains a concern as incremental loading gradually adds more weight to this weak layer. Test profiles continue to show easy shears on this layer & there are reports of "whomphing" which is a collapse of this weakness. Slopes that have not avalanched in the last week are of particular concern for this persistent weakness. The lower snowpack is generally strong and well settled.


Wind Slabs

An icon showing Wind Slabs
Big winds combined with plenty of snow available for transportation have resulted in widespread wind slabs on lee slopes. I'd be suspect of any open slope, even around treeeline.

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

Elevations: Alpine, Treeline.



Expected Size

2 - 5

Persistent Slabs

An icon showing Persistent Slabs
Surface hoar buried about a meter below the surface has created a dangerous and tricky avalanche problem. Activity has slowed in the Caribou's, but this layer needs to be treated with great caution. It's time to rein terrain choices way in.

Aspects: All aspects.

Elevations: All elevations.



Expected Size

3 - 7

Valid until: Jan 1st, 2012 8:00AM