Avalanche Forecast

Issued: Feb 24th, 2016 8:19AM

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

Avalanche Canada pgoddard, Avalanche Canada

Avalanche danger may be higher in the north of the region, where a buried weak layer has been recently reactive.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

The Jetstream clips the region, while directing the most intense precipitation north of the area. On Thursday, 5-10 cm snow is expected with the freezing level climbing to around 1500 m. Winds become strong from the south-west. Light snow is expected on Friday, with winds easing. There is a lull in the weather forecast for Friday night/ Saturday.

Avalanche Summary

Isolated wind slab avalanches were reported over the last couple of days. In the north of the region, a small natural avalanche that stepped down to the early January surface hoar on Sunday is a good reminder that this layer needs to remain a concern. Deeply buried persistent weak layers in the alpine also woke up in the north of the region over the weekend when several large avalanches released on basal facets. This weak layer was reported to be reactive to skier triggering from thin spots, as well as heavy triggers such as a smaller avalanches or cornice failures.

Snowpack Summary

Alpine areas are reported to be widely wind effected with wind pressed surfaces found in exposed areas and a mixture of hard and soft slabs present in lee features. A thin crust may cap moist snow at or just below the surface at lower elevations and on slopes that see direct sun. The upper snow pack is reported to be bonding well to a crust buried on February 12th, now 40 to 80 cm down, that extends up to around 2000 m. The early January surface hoar can be typically be found between 60 and 140 cm down. Although it is getting harder to trigger this layer, it remains a concern. Shallow snowpack areas also have a weak base layer of facetted snow just above the ground.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs exist on many slopes. It may be possible to trigger these with the weight of a person or snowmobile.
Be alert to conditions that change with elevation. >Be aware of the potential for wide propagations due to the presence of hard windslabs.>Travel on ridges and ribs to avoid wind loaded areas. >

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
Large avalanches can be triggered from thin snowpack areas, or by heavy loads such as a cornice release or smaller avalanche.
Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, widely propagating avalanches due to the presence of buried weak layers.>Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Feb 25th, 2016 2:00PM

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