Avalanche Forecast

Issued: Feb 1st, 2017 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

We have moved to a "Moderate" rating due to lack of natural activity. Keep in mind that the snowpack is inherently very weak, and large avalanches are still possible. If there is a slab overlying facets, its suspect. SH

Summary

Weather Forecast

Lows of -20C rising to around -15C with light North winds and sunny skies for Thursday.Â Some slightly increased winds Friday, but the potential story is significant snow currently in the books for this weekend in some areas.Â We will see how much actually materializes closer to the time, but stay tuned.Â

Snowpack Summary

Previous strong to extreme W winds have created harder wind pressed surfaces at treeline and above. Isolated surface hoar may be found buried in sheltered locations at treeline and below. Generally the midpack is weak at TL and above, and the entire snowpack is weak BTL. Near the divide, deeper snow-packs are a bit stronger and more supportive.

Avalanche Summary

We had a small avalanche cycle this past weekend due to big winds, but as temperatures have cooled and winds abated, the activity has slowed down significantly. No new avalanches reported or observed Wednesday.

Confidence

Due to the number and quality of field observations

Problems

Deep Persistent Slabs

The snowpack is weak. Slopes where a slab sits over the deeper weak layers should be treated as suspect. Until we get some rounding or compression, the snowpack is going to remain fragile to input.

Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Activity on new wind slabs has slowed down due to colder temperatures, but watch for them in steep exposed areas at upper elevations. Up until 2 days ago there was quite a bit of wind slab avalanche activity.

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 2nd, 2017 4:00PM