Avalanche Forecast

Issued: Mar 1st, 2023 4:00PM

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

Avalanche Canada IJ, Avalanche Canada

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Snow and wind is forecast over the next few days. Expect a small increase in the avalanche danger until the weather calms down again.

Summary

Confidence

Moderate

Avalanche Summary

Forecasters investigated a size 2 skiier remote avalanche from yesterday in the Wild West area at Sunshine Village. This failed 65 cm down on one of the January PWLs.

Otherwise, Lake Louise ski hill reported triggering a few small windslabs in alpine terrain and Sunshine snow safety team observed a size 1.5 naturally triggered windslab out of north facing alpine terrain.

Snowpack Summary

Wind slabs are present in the alpine and at treeline. These wind slabs overlie the various Jan PWL interfaces of sun crusts, facets, and surface hoar down 80-120 cm. The weaker Nov 16 basal facet layer is down 100-200 cm, and produces moderate to hard sudden collapse results. Deeper snowpack areas west of the divide are stronger and more supportive than areas to the east.

Weather Summary

A system is moving in from the Alaskan Gulf on Thursday, followed by convective flurries for Friday, tapering Saturday. We should see ~ 2 cm by Thursday AM.

Thursday: ~ 5 cm. Alpine winds strong from the SW. Treeline temperatures -5 to -10.

Friday: ~ 5 cm. Alpine winds moderate from the W. Treeline temperatures -8 to -10.

Saturday: Light south alpine winds. Low near -20 in the AM. Light flurries in the afternoon.

Terrain and Travel Advice

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs from last weeks storm are becoming more stubborn, but incoming snow and winds will build new ones over the next few days. Remain vigilant in lee areas where wind slabs are more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Three persistent weak layers formed in January are down 70-100 cm. The biggest concern is triggering these buried suncrusts on steep solar slopes, but weaker facets and isolated surface hoar can be found on the same interface on shaded aspects.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Weak facets and depth hoar are present at the bottom of the snowpack. Incoming snow and winds over the next few days will increase load on our fragile snowpack. Be especially cautious in thin snowpack areas, which are likely areas for triggering.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Mar 2nd, 2023 4:00PM

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