Avalanche Forecast

Issued: Jan 2nd, 2023 4:00PM

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

Avalanche Canada ldreier, Avalanche Canada

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It's still possible for riders to trigger large, persistent slab avalanches.

Summary

Confidence

Moderate

Avalanche Summary

A rider triggered a small avalanches in an opening, as shown in this MIN. The avalanche likely released on one of the weak layers described in the Snowpack Summary and shows that this layer could still be triggered in specific terrain. Caution should be taken in challenging or complex terrain given the uncertainty and consequence of large avalanches.

Snowpack Summary

Around 50 cm of snow sits on a hard melt-freeze crust found up to treeline elevations formed by rain on December 26. Moist snow or a surface crust may be found up to around 1600 m on all aspects and up to ridgetop on sun-exposed slopes.

Two deeper layers of surface hoar and facets could still be triggered in specific terrain. These include a 40 to 80 cm deep layer buried mid-December and an 80 to 150 cm deep layer buried mid-November. These layers are generally deeper around Fernie and shallower towards Sparwood and Elkford. The layers may be easier to trigger where they are buried within the top 100 cm of the snowpack.

Weather Summary

Monday Night

Clear with no precipitation, 15 km/h southwest wind, light inversion, treeline temperature -5 °C.

Tuesday

Increasing cloud coverage with a trace of snow, 20 km/h southwest wind, treeline temperature -9 °C.

Wednesday

Mix of sun and cloud, trace of new snow, 20 to 30 km/h westerly wind, treeline temperature -12 °C.

Thursday

Mostly cloudy, trace of new snow, 20 to 30 km/h south wind, treeline temperature -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Buried weak layers are likely gaining strength but the possibility of triggering a large persistent slab avalanche remains. There are two weak layers, both composed of surface hoar and facets, anywhere from 40 to 150 cm deep. It may be more likely to trigger these layers where they are buried relatively shallow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 3rd, 2023 4:00PM

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