Avalanche Forecast

Issued: Jan 24th, 2024 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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Storm slabs are resting on a layer of facets and will be slow to bond. Reactivity may persist longer than usual.

Be mindful of buried weak layers that have produced large recent avalanches.

Summary

Confidence

Moderate

Avalanche Summary

Storm slabs have been reactive, sliding on a facet layer below the recent storm snow. A natural cycle was observed Sunday up to size 2. On Monday and Tuesday, numerous rider-triggered avalanches, (including, ski cuts, accidentally and remotely triggered avalanches) were reported size 1-2.

Buried weak layers have also been active in recent days. Naturals have been reported to size 3, as well as several size 1-2 triggered by riders from shallow, weak or rocky spots.

Snowpack Summary

15 to 30 cm of recent snow sits poorly bonded to old surfaces including faceted snow, surface hoar and firm wind slabs.

The mid pack contains a few layers of concern including a surface hoar/facet/crust layer buried 60 to 80 cm deep.

130+ cm down another surface hoar layer exists that was buried in early December. This seems to be of most concern above 2000 m where a robust crust doesn't exist above it, or in shallow snowpack areas.

Weather Summary

Wednesday night

Mostly cloudy with flurries bringing around 5 cm of new snow. South alpine wind 40 km/h. Treeline temperature -3 °C.

Thursday

Mostly cloudy with flurries brining around 5 cm of new snow. South alpine wind 30-40 km/h. Treeline temperature -2 °C. Freezing level 1300 m.

Friday

5-10 cm of new snow overnight then a mix of sun and cloud. Southwest alpine wind 30-40 km/h, treeline temperature -1 °C, freezing level 1400 m.

Friday

Mostly cloudy with flurries brining around 5 cm of new snow. Southwest alpine wind 40-50 km/h. Treeline temperature 0 °C. Freezing level 1800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Storm Slabs

An icon showing Storm Slabs

New storm slabs have been building with continued snow and warm weather. They are resting on a weak layer of facets and in places surface hoar. This could mean they will be more reactive and slower to bond.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

Two weak layers of surface hoar and facets exist deeper in the snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Basal facets remain a concern in steep, rocky alpine features with thin-to-thick snowpack transitions.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Jan 25th, 2024 4:00PM

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