Avalanche Forecast

Issued: Jan 13th, 2019 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Deep persistent slab problems require a disciplined approach to terrain choices. Our current condition will be slow to improve.

Summary

Weather Forecast

Continued warm temperatures with increasing cloud is expected tomorrow. No precipitation is anticipated until the end of next week. Some of the models show a mild temperature inversion. Additionally, the wind is expected to reach the moderate to strong velocity range from the west.

Snowpack Summary

Snowfall since Jan2 has been redistributed by southwest winds yielding extensive wind effect in the alpine. In thick snowpack areas, the Dec 10th weak layer of facets is now down 100-150cm with a stronger snowpack below. In thin snowpack areas, there is little separation between Dec 10 and the weak depth hoar/ facets sitting 40 cm above the ground.

Avalanche Summary

Explosive control today at ski hills in previously controlled terrain produced minimal results, and reports were that the wind slabs were less reactive than yesterday.

Confidence

Due to the number of field observations on Sunday

Problems

Deep Persistent Slabs

The facets and depth hoar 40 cm above the ground inspire little confidence. Some large natural avalanches are still occurring and human triggering is likely. This layer needs time to adjust to the load and 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

Wind Slabs

These wind slabs are becoming less reactive but should be treated with respect if encountered. If initiated these slabs could provide enough load to trigger the deeper basal layers.

Use caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 14th, 2019 4:00PM