Avalanche Forecast

Issued: Mar 30th, 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 and Persistent Slabs.

Avalanche Canada Mikey, Avalanche Canada

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Cooler snowy weather is coming for this weekend. The Deep Persistent Slab problem is still a major concern when travelling. Conservative route finding is advised.

Summary

Confidence

Moderate

Avalanche Summary

No avalanches have been reported today. But in the last three days, there have been two size 3 natural avalanches and one skier triggered on Miner's Gully. Check out this MIN for photos of the skier-triggered slide in Miner's Gully,

Snowpack Summary

Approximately 25cm of settled snow remains dry on polar aspects and has seen little wind effect. Expect some wind effect starting on Friday with forecast winds. However, solar aspects have now seen several generations of sun crust, and will likely be moist when the sun comes out.

Forecasters are tracking 3 main weak layers in the snowpack. First, a buried sun crust on solar aspects, or a layer of facets on polar aspects, are producing some natural and human-triggered avalanches down between 20 and 40cm. Second, a weak layer of facets buried back in late January has occasionally been active down 80 to 100cm. A very large human-triggered avalanche occurred on this layer late last week. And finally, the basal weaknesses remain. Deep persistent slab avalanches are still possible, especially in shallow snowpack areas. This deep layer may also be prone to "waking up" as slopes start to get more significant solar input. Forecasters continue to have zero confidence in larger terrain features, and we continue to avoid significant overhead terrain.

Weather Summary

Friday will be a mix of sun and cloud until the flurries begin near noon with temperatures between -8c and -3c. Winds are forecast to increase throughout the day from light to strong out of the SW.

Saturday and Sunday: Cooler with snow accumulation of 10-20cm by Sunday night

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Thin, shallow areas or heavy triggers are what will set this layer off. Avoid terrain with those characteristics. Intense solar radiation and daytime heating may wake up this layer.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Persistent Slabs

An icon showing Persistent Slabs

There are two layers of concern here: 1) a buried sun crust (on solar) and facets (on polar) down 20-40cm, and 2) a facet/depth hoar layer down 80-100cm that was buried mid season. These layers have become more active within the recent additional snow load, and are more prone to triggering during periods of intense solar radiation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Mar 31st, 2023 4:00PM