Avalanche Forecast

Issued: Dec 21st, 2014 7:28AM

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

jlammers, Avalanche Canada

South Rockies.

This bulletin was published with very little field data. If you've been in the mountains, we'd love to hear from you. Observations can be sent to forecaster@avalanche.ca.

Summary

Confidence

Poor - Due to the number and quality of field observations

Weather Forecast

On Monday and Tuesday a dry upper ridge will bring mainly sunny skies, light northwest winds and freezing levels around valley bottom. Overnight Tuesday and Wednesday, expect increased cloud and light snowfall as a pacific system moves eastward into the region. With this system we can expect 5-15cm of snow, strong westerly winds and freezing levels at about 1100m.

Avalanche Summary

Explosives control produced a few size 1 and 2 wind slab avalanches on Sunday. If you have any avalanche observations to report, please send an email to forecaster@avalanche.ca.

Snowpack Summary

Generally light amounts of snow have fallen in the last few days. In the alpine, winds have been conducive to blowing this snow into thin wind slabs in exposed lee areas. Below the recent storm snow you may find a layer of surface hoar. Below this, about 20cm of settled snow overlies a thick hard supportive rain crust that extends from the valley to alpine elevations. The crust is effectively bridging triggers from penetrating to deeper persistent weaknesses that formed earlier in the season. However, on high alpine slopes above the recent rain line poorly bonded crusts, facets, and/or buried surface hoar may be susceptible to triggers. Professionals are still concerned with a buried crust from November, down 50-70 cm, that could be triggered by large loads.

Problems

Wind Slabs

Light amounts of recent snow have been shifted by wind into pockets of wind slab in exposed lee terrain. Watch for triggering in gullies and below ridge crests.

Avoid freshly wind loaded features.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 22nd, 2014 2:00PM