Avalanche Forecast

Issued: Mar 8th, 2023 4:00PM

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

Avalanche Canada IJ, Avalanche Canada

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We've noticed several cornice failures over the last few days. These are likely triggered by solar radiation and generally triggering large avalanches on the slopes below.

As fresh lines become scarce, resist the urge to step into bigger terrain.

Summary

Confidence

Moderate

Avalanche Summary

Although avalanche activity is tapering, we are still seeing daily natural and explosive triggered avalanches. On Wednesday, field teams near Bow Lake observed a size 3 natural on a NW cross loaded aspect in the alpine that initiated as a windslab and stepped down to deeper layers.

LL ski hill triggered a size 2.5 on a reloaded bed surface for the 3rd time this season in steep alpine east facing terrain.

Likely triggers for natural avalanches are cornice failures and solar radiation and possibly both.

Snowpack Summary

Alpine and exposed treeline areas are wind effected with wind slabs that are slowly becoming less reactive. Steep solar slopes at treeline and below have a thin sun crust. The various Jan PWL interfaces of sun crusts, facets, and surface hoar are down 50-90 cm. The weaker Nov 16 basal facet layer is down 120-170 cm and is still present but not consistently reactive in test pits.

Weather Summary

Stable weather continues on Thursday before a small system moves in on Friday. Consistent diurnal temperature swings with lows near -20, highs to -5 throughout the period.

Thursday: Clear and calm.

Friday: Snow starting near noon. 2- 5 cm with moderate NE alpine winds.

Saturday: Clearing with light NW winds.

For a more detailed weather forecast, click here.

Terrain and Travel Advice

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Uncertainty is best managed through conservative terrain choices at this time.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Weak facets and depth hoar are still present at the bottom of the snowpack and inspire little confidence. Be especially cautious in thin snowpack areas, which are likely areas for triggering. Cornices may also trigger this layer, especially if the sun is out in the afternoon.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Persistent Slabs

An icon showing Persistent Slabs

Three persistent weak layers formed in January are down 50-90 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

Wind Slabs

An icon showing Wind Slabs

Isolated windslabs still exist in alpine areas and may be a trigger for the deeper layers.

Aspects: North, North East, East, South East, South, North West.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Mar 9th, 2023 4:00PM