Avalanche Forecast

Issued: Dec 21st, 2012 10:02AM

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

jfloyer, Avalanche Canada

South Rockies.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Overnight Friday: 5-10 cm new snow with strong SW winds and treeline temperatures around -10C.Saturday: light snow (2-5 cm) with winds gusting to 40 km/h at Ridgetop. Treeline temperatures around -10C.Sunday: 5 cm snow expected overnight Saturday, but during the day on Sunday, things should be mostly dry. Moderate SW winds. Treeline temperatures around -8C.Monday: 5 cm new snow. Moderate SE winds. Treeline temperatures falling to -18C.

Avalanche Summary

On Friday, a size 2 avalanche was triggered by a skier on a northeast aspect at 1900 m. The fracture depth was 30 cm and the slide ran for 150 m.

Snowpack Summary

Variable amounts of new snow have given storm slab depths ranging from approximately 20 to 50 cm. Extensive wind transport has build big wind drifts in many areas behind exposed terrain features. Two crusts have been identified in the snowpack: one close to the ground that formed in early November and one around 90 cm below the surface, which formed in early December. Snowpack tests indicate these crusts are well bonded to the snow above and below.

Problems

Storm Slabs

The new storm has set up a storm slab on all aspects. Strong SW winds have transported storm snow into thick and touchy slabs on mainly north through east aspects.

Note recent avalanche activity.>Be cautious as you transition into wind affected terrain.>Whumpfing, shooting cracks and recent avalanches are all strong indicators of an unstable snowpack.>The best powder will be found in sheltered locations at or below treeline.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Valid until: Dec 22nd, 2012 2:00PM