Avalanche Forecast

Issued: Dec 10th, 2015 4:24PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Now is an excellent time to put your snow profile skills to work - the Dec 3 surface hoar layer is widespread below 1800 m. Dig down, look for this layer, and test it - this has the potential to become a tricky persistent slab avalanche problem.

Summary

Weather Forecast

The main storm pulse is now over for the Rockies, but expect Friday to be overcast with flurries and accumulations of a few centimeters. Temperatures will range from -4 to -10 and winds will be light to moderate from the west.

Snowpack Summary

50-70 cm of storm snow has fallen over the past 7 days, now settled into a cohesive slab overlying a significant weak layer of surface hoar below treeline (and just into treeline). Distribution of this layer is still vague, but you should assume it's widespread below 1800 m. In the alpine, winds from the recent storm have left widespread windslabs.

Avalanche Summary

Avalanche control at the Sunshine ski resort produced small slab avalanches in leeward areas, but otherwise no significant avalanches have been reported - keep in mind that backcountry observations have been very limited over the past week.

Confidence

Due to the number of field observations

Problems

Storm Slabs

40-70cm of storm snow has fallen over the week, now settled into a slab overlying a dangerous layer of surface hoar below treeline. Treat all slopes below treeline with suspicion until you can rule out this weak layer.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

The recent storm was accompanied by moderate to strong winds at treeline and above. For a few more days, watch out for fresh windslabs in typically suspicious areas after a storm: leeward and cross loaded slopes or slopes near ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 11th, 2015 4:00PM