Avalanche Forecast

Issued: Apr 24th, 2023 4:00PM

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

Avalanche Canada CJ, Avalanche Canada

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Start and finish early to take advantage of better travel and a lower likelihood of upper snowpack avalanches while the surface snow remains frozen. Also, keep the deep persistent slab in mind as this remains a concern and can be triggered regardless of surface snow conditions.

Summary

Confidence

Moderate

Avalanche Summary

Some small loose wet avalanches have been observed in the past few days on steep solar aspects or at low elevations with daytime warming. A size 3 skier-triggered avalanche failing on the basal facets occurred in a closed area within the Lake Louise ski resort on Saturday.

Snowpack Summary

3-8 cm new snow. Solar aspects are getting moist in the afternoon, creating new crusts daily, and multiple buried crusts are present. On northerly aspects, temperature crusts are present up to 2200 m, with 10-20 cm of preserved surface snow above this elevation and some wind transport at ridge crests. The base of the snowpack remains weak due to the presence of facets and depth hoar.

Weather Summary

Light flurries, moderate west winds and freezing levels down to 1500 m are expected Monday night.

On Tuesday freezing levels will climb to about 2100 m with moderate west winds and continued light flurries. Light rain is possible at valley bottoms. No significant accumulations are expected.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The weak basal facets and mid-pack facets/crusts will remain a concern for the foreseeable future. Daytime heating may also increase the likelihood of triggering this weakness. Stick to well supported lower angle terrain to avoid this problem.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Storm Slabs

An icon showing Storm Slabs

Watch for new snow instabilites especially in places where convective weather cells have deposited more snow. Areas with new snow over a crust, recently wind loaded slopes, or places where the surface snow is becoming moist are the main concerns.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

With rising daytime freezing levels, expect moist snow at lower elevations with the potential for wet loose avalanches to occur. Any sunny breaks will also contribute to this problem on steep solar aspects up into the alpine.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Apr 25th, 2023 4:00PM

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