Avalanche Forecast

Issued: Jan 10th, 2019 4:00PM

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

Parks Canada snow safety, Parks Canada

New windslabs are being formed in lee areas. Slabs can step down to deeper instabilities creating large avalanches that can run full path. Field ice climbers should be aware of a thinner snowpack and basal instabilities at lower elevations.

Summary

Weather Forecast

Warmer temps and steady moderate winds are forecast. Along with light snow over the weekend avalanche conditions should remain static.

Snowpack Summary

Up to 70 cm of recent snow with variable wind effect has put a dense slab over the persistent weak layers. In thicker snow pack areas, the Dec. 10th weak layer of facets is now down 100-150cm with a stronger snowpack below. In thin snowpack areas, the Dec.10th layer is mixed in with the October 26 basal facets and crust.

Avalanche Summary

Numerous avalanches were reported today on east and north facing slopes in the Banff area to size 2.5 Thursday. It is likely this was the result of warming temperatures and new wind loading.

Confidence

Problems

Persistent Slabs

An icon showing Persistent Slabs
The Dec.10 layer of facets and some surface hoar are down 150+cm at treeline. There have been few observations from this deeper snowpack region as to the sensitivity of this layer, but recent avalanche control has seen deep propagations.
Be aware of the potential for wide propagations which could result in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3.5

Wind Slabs

An icon showing Wind Slabs

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Jan 11th, 2019 4:00PM