Avalanche Forecast

Issued: Jan 19th, 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 SH, Avalanche Canada

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Good skiing can be found on low-angled terrain above treeline. The snowpack remains generally shallow and weak, a little less so to the West. Do not lose sight of the unpredictable nature of the deep persistent slab problem even though conditions appear to have improved.

Summary

Confidence

Moderate

Avalanche Summary

A few small surface avalanches triggered by explosives were reported by Lake Louise patrol today. No other avalanches observed or reported.

Snowpack Summary

Dribs and drabs of snow over the past 2 weeks have amounted to 10cm. This sits on 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

30-50km/h westerly alpine winds overnight into Friday AM, then diminishing to 20-40km/h from the NW. Temperatures will remain at valley bottom with highs of -5C to -10C at ridgetop.

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 forecasting 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

1.5 - 2.5

Wind Slabs

An icon showing Wind Slabs

It is forecast to be windy on Thursday night, which could blow the 10cm of low-density snow into wind slabs on lee aspects.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Jan 20th, 2023 4:00PM