Avalanche Forecast

Issued: Jan 27th, 2023 4:00PM

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

Avalanche Canada rgoddard, Avalanche Canada

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Significant snowfall accumulation starting Friday afternoon will continue throughout the night.

Expect redistribution by moderate to strong winds slabs to form and new snow to be transported by associated wind.

Enjoy the powder but don't let it lure you into terrain with high consequences.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were reported in our area on Thursday. Avalanche control with the use of explosives produced three size 1.5 avalanches from wind slabs in the Fernie area on Wednesday. Ski cutting on Monday and Tuesday yielded more size 1 avalanches also produced from wind slabs.

Although the deep persistent slab problem has not produced in they have not produced any avalanches for some time it could still pose a threat for now. Be wary of areas with thin or variable depth snowpack and shallow rocky start zones throughout the region.

Snowpack Summary

New snow will be falling on wind slabs at higher elevations. Below treeline a surface hoar layer will be getting buried in sheltered areas and on south-facing aspects, a melt-freeze crust can be found getting covered over.

A crust/facet layer, 2 to 15 cm thick at treeline is 50 to 90 cm below the surface. Where it's thickest, it caps the settled and consolidated mid-snowpack.

Another crust/facet layer is down 70 to 150 cm. Below this crust, the basal snowpack is weak and faceted. The total snowpack depth ranges between 90 and 250 cm.

Weather Summary

Friday Night

Cloudy, 10 to 20 cm accumulation, winds northeast 20 km/h gusting to 40, treeline temperatures around -10 C.

Saturday

Clearing, trace accumulation, winds northeast 15 to 30 km/h, treeline temperatures -21 C.

Sunday

Mostly sunny, possible trace accumulation, winds northeast 15 km/h gusting to 32, treeline temperatures getting down to -25 C.

Monday

Mostly sunny, no accumulation, winds west 15 km/h, treeline temperatures -19 C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • 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

Snow that started Friday afternoon and continued into the evening will be accompanied with moderate to strong winds that will be switching direction from southwest to northeast. This will be sitting on a range of surfaces that could include wind slabs, surface hoar, and / or a melt freeze crust. See snowpack summary for more details.

Expect wind slabs in exposed areas and reactive storm slabs everywhere else.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 1.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Faceted grains make up the basal snowpack and are gaining strength very slowly. This layer has been relatively quiet recently but can still be triggered with a heavier load, like a cornice fall for example, and in areas with a thinner snowpack. Any avalanche triggered this deep will likely be large and destructive.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 28th, 2023 4:00PM