Avalanche Forecast

Issued: Apr 26th, 2023 4:00PM

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

Avalanche Canada DH, Avalanche Canada

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Warm temperatures will produce large avalanches, avoid avalanche terrain in the heat of the day.

Summary

Confidence

Moderate

Avalanche Summary

Numerous moist/wet, loose surface avalanches have been observed from steep gullies/slopes on all aspects at and below treeline. These point releases gather substantial mass as they move downslope into warmer snow.

As the week continues to warm up, expect these wet/loose avalanches to increase in size and potentially step down to deep layers, possibly even the Nov 17 facets.

Snowpack Summary

5cm of new snow sits over a crust at upper treeline and alpine except for high north aspects. Below this are several buried crusts on solar aspects which may provide a failure plane for slab avalanches as temps rise dramatically today.

Below treeline the snowpack is moist and has been weakened by rain and warm temperatures.

20-40cm above the ground the Nov 17 basal weakness can still be found in many areas.

Weather Summary

A strong ridge of high pressure is delivering very warm temperatures with high freezing levels and sunny skies.

Thurs: sun w/ cloudy periods, Alp high 2 °C, light west winds, FZL 2800m

Fri: sunny skies, Alp high 9°C, light west winds, FZL 3400m

Sat: mix of sun and cloud, Alp high 11°C, light southwest winds, FZL 3600m.

Terrain and Travel Advice

  • As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
  • If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.

Problems

Loose Wet

An icon showing Loose Wet

With intense solar heating the surface snow will quickly loose what little strength was recovered overnight and during yesterdays snowfall. Loose wet avalanches will be easily triggered in steep terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs

Up to 60cm of settled snow covers a series of crusts combined with surface hoar/facets in some locations. Loose wet avalanches in motion have the potential to step down to these layers, creating large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The increasing warmth and rain is percolating deeper into the snowpack. The potential for this early season basal weakness to wake up increases with these two added inputs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4.5

Valid until: Apr 27th, 2023 4:00PM

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