Avalanche Forecast

Issued: Jan 10th, 2023 4:00PM

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

Avalanche Canada AB, Avalanche Canada

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Continued low confidence in the overall snowpack structure is being felt by forecasters, despite recent benign weather and fewer natural and explosive-triggered avalanches of late. Increasing wind and warm temperatures on Thurs/Fri will likely contribute to worsening conditions.

Remain vigilant and settle in for a long winter of making conservative terrain choices to avoid negative interactions with avalanches.

Summary

Confidence

Moderate

Avalanche Summary

No avalanches were observed or reported in Little Yoho today.

Snowpack Summary

10-20 cm of recent storm snow sits over a denser mid-pack which has formed a slab over the weak facet layers below. The December 17 persistent layer of surface hoar/facets is down 25-60 cm and becoming less reactive. The November 16 deep persistent layer of facets, depth hoar, and/or sun crusts is found near the base of the snowpack with test results continuing to show sudden failures. Puzzle Peak snow profile today.

Weather Summary

On Wednesday, clear in the morning, with increasing clouds in the afternoon. No precipitation. Valley temperatures are about -4 and the ridge about -10. Wind increasing to moderate/strong from the SW into the afternoon.

Terrain and Travel Advice

  • Uncertainty is best managed through conservative terrain choices at this time.
  • Use careful route-finding and stick to moderate slope angles with low consequences.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The lower snowpack is comprised of very weak facets, with the mid and upper snowpack forming a slab over these facets at all elevations. This weak basal layer is fairly uniform across most of the terrain and has shown the potential for human triggering, long propagations and remote triggering.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Persistent Slabs

An icon showing Persistent Slabs

The December 17 layer of persistent weak facets that formed during the prolonged deep freeze in early December is down 30-60 cm. This layer appears to be gaining strength, but is still worth considering. If a failure initiates on this layer, it may step down to the deep persistent layers resulting in larger avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 11th, 2023 4:00PM

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