Avalanche Forecast

Issued: Jan 31st, 2016 4:00PM

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

Aaron Beardmore, Parks Canada

Banff Yoho Kootenay.

Manage overhead exposure carefully and make judicious terrain choices as large slides are still likely at all elevations. Potential still exists for human triggering of large avalanches.

Summary

Weather Forecast

Cooling temperatures (-10 to -15), very light snowfall coupled with light wind for the next few days.

Snowpack Summary

Windslabs in alpine and treeline areas, and new cornices in the alpine. 30-60cm of snow sits over the Jan 6 surface hoar/facet layer and is reactive to skier triggering. Snowpack tests today 1800m in Kootenay yielded moderate compression test results on both the Jan 6 and Dec 3 layers down 55 and 85cm respectively. (surface hoar at this location).

Avalanche Summary

No reported or observed avalanche activity today. However, an extensive natural cycle of avalanches up to size 3 during the past 72 hours with slabs propagating up to several hundred meters and over 40cm deep on many slopes. Conditions remain ripe for human triggering and occasional large natural avalanches.

Confidence

Problems

Wind Slabs

Recent wind has built soft slabs 30 to 50cm deep in lee areas and established new growth on cornices. Although these slabs generally exist at upper elevations, avalanches have the potential to run a long distance.

Avoid steep lee and cross-loaded featuresAvoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

30-60 cm of settled snow overlies the Jan 6 layer of surface hoar and facets. This continues to be reactive to both human triggering with potential for failures to step down into deeper snowpack layers and result in large avalanches.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.Avoid open slopes with any steepness over 30 degrees.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Feb 1st, 2016 4:00PM