Avalanche Forecast

Issued: Dec 25th, 2013 8:26AM

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

Avalanche Canada mbender, Avalanche Canada

Summary

Confidence

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

Weather Forecast

Thursday: Light snowfall accumulations up to 5cm. Alpine temperatures -3. Ridgetop winds light-moderate from the SW. Freezing levels rising to 1200 m.Friday: Mix of sun and cloud with intermittent flurries. Alpine temperatures near -5. winds moderate gusting to strong from the southwest. Freezing levels 1000 m.Saturday: Cloudy with some sunny periods, alpine temperatures -7 and light northwesterly winds.

Avalanche Summary

On Tuesday, explosive avalanche control initiated many size 1-1.5 slab avalanches on SE-SW aspects above 1600 m. On Monday, numerous natural avalanche activity was reported up to size 1.5 on NE-NW aspects above 2000 m. Skier triggered avalanches up to size 1 were not uncommon.

Snowpack Summary

Up to 20 cm of recent new snow and strong westerly have winds formed pockets of soft wind slab on lee slopes. A layer of surface hoar is buried 15-20 cm down, and has been reactive with the new snow, mainly causing loose dry sluffing from steeper terrain.A little deeper (between 35 - 50 cm below the surface) you may find a weak layer of surface hoar on sheltered slopes or a crust/facet combo on steep solar aspects. This layer is dormant, and there is not a deep enough overlying slab to create a significant hazard. That said I'd recommend keeping it on the radar, especially as the snow load above increases.In general, snowpack depths are below seasonal average with many slopes below treeline still reported to be below threshold for avalanche activity. A deeper snowpack is likely in the northern part of the region.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and recent winds have formed slabs in the lee of terrain features.
Use ridges or ribs to avoid pockets of wind loaded snow.>Avoid lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 26th, 2013 2:00PM