Avalanche Forecast

Issued: Jan 6th, 2019 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Wait a little bit longer for the storm snow to settle. Human triggering still likely. Make conservative terrain choices.

Summary

Weather Forecast

A short pulse of precip came through Bow Summit today that deposited about 5cm of snow. It is expected to clear tonight and into tomorrow. Temperatures will remain seasonal. The wind has been over forecasted of late, but expect moderate velocity from the SW.

Snowpack Summary

Up to 70 cm of storm snow with variable wind effect has put a dense load over the persistent weak layers. In thicker snow pack areas, the Dec. 10th weak layer of facets is now down 80-120cm with a stronger snowpack below. In thin snowpack areas, the Dec.10th layer is mixed in with the basal facets and October crust.

Avalanche Summary

The natural avalanche cycle has tapered off, but conditions are still primed for human triggering. Wide propagations were observed near Serac Creek in Kootenay National Park today. They likely ran in the height of the storm (Friday). They were reported as approx 40cm deep and size 2.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Problems

Deep Persistent Slabs

There is the very real potential of a slab initiating on the weak basal layers (Oct. 30 layer), or a storm slab "stepping down" to cause a large avalanche. This problem will be around for some time.

Be aware of the potential for wide propagations which could result in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3.5

Storm Slabs

Lots of recent snow load will require some time to stabilize. These storm slabs exist in many areas and should be treated with caution in avalanche terrain, but should only be a problem in the short term. Expect it to last for a couple more days.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Jan 7th, 2019 4:00PM