Avalanche Forecast

Issued: Dec 30th, 2013 8:02AM

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

ali haeri, Parks Canada

Glacier.

Cornice hazard is becoming more of a concern from steady snowfall amounts and winds recently, so watch for that overhead hazard.

Summary

Weather Forecast

Unsettled westerly flow weather pattern continues to bring light amounts of precipitation into tomorrow. Up to 10cm forecast today. Freezing levels are expected to rise to 1300m. Brief ridge of high pressure builds for Wednesday with a drop in temperatures and pushed out on Thursday by a more significant Pacific frontal system.

Snowpack Summary

70 cm of settling storm snow,. The December 8 surface hoar/facet layer is down ~85cm and the November 28 surface hoar layer is down ~110cm still well preserved in certain areas.

Avalanche Summary

4 natural slab avalanches yesterday from size 2.0 to 2.5 in the highway corridor east of the Rogers Pass summit.

Confidence

Problems

Wind Slabs

Winds have been steady in the moderate to strong range for the past 24hrs.

Be cautious as you transition into wind affected terrain.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Storm Slabs

Mild temperatures today will make slab formation more likely.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

2 buried weak layers down 70 to 110cm remain a concern for riders. Consequences would be large if triggered which is more likely from shallow snowpack areas.

Dig down to find and test weak layers before committing to a line.Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Dec 31st, 2013 8:00AM