Avalanche Forecast

Issued: Jan 21st, 2023 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.

Avalanche Canada AL, Avalanche Canada

Email

The upper snowpack is becoming more supportive, allowing for better travel. Bear in mind that this supportive upper snowpack is a slab overlaying weak, very unsupportive, faceted snow. This structure is not to be trusted.

Stick to low-consequence terrain.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanche activity was observed today. Friday, Lake Louise patrol triggered wind slabs to size 1.5 on immediate alpine lee slopes.

Snowpack Summary

10cm overlays a surface hoar /crust layer which is sporadic in the region. The Dec 17 surface hoar/sun crust layer is down 25-50cm, and generally not reactive. The Nov. 16 deep persistent layer is down 40-90cm and continues to produce sudden failures in snowpack tests. In Little Yoho, these two layers are deeper and more spread apart in the snowpack.

Weather Summary

A cold front moving in Saturday evening will bring up to 5cm of snow accumulation to the region. Clearing will begin Sunday as another ridge builds. Moderate ridge winds will remain till the end of the weekend.

Terrain and Travel Advice

  • Uncertainty is best managed through conservative terrain choices at this time.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The lower snowpack is comprised of weak facets and depth hoar with the upper snowpack forming a 40 to 90cm thick slab above. This weak basal layer is uniform across most of the forecast region and has been responsible for most of the avalanche activity to date this season.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Wind Slabs

An icon showing Wind Slabs

Previous moderate to strong winds have formed isolated winds slabs on immediate lee slopes in the alpine.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Jan 22nd, 2023 4:00PM