Avalanche Forecast

Issued: Apr 6th, 2018 3:56PM

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

Avalanche Canada jmcbride, Avalanche Canada

Strong to extreme winds have created wind slabs in leeward areas. Avoid freshly wind-loaded slopes and features, these may be primed for human triggering.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TONIGHT: Flurries. Accumulation 2-4 cm. Ridge wind strong, southeast. Alpine temperature near -5. Freezing level 300 m.SATURDAY: Mix of sun and cloud. Ridge wind strong to extreme, southeast. Alpine temperature near -0. Freezing level 1200 m.SUNDAY: Cloudy, flurries. Accumulation 2-6 cm. Ridge wind moderate, southwest. Alpine temperature near 0. Freezing level 1500 m. MONDAY: Cloudy, light flurries. Accumulation up to 4 cm. Ridge wind moderate to strong, south. Alpine temperature near 0. Freezing level 1500 m.

Avalanche Summary

Thursday there were reports from northern parts of the region of a widespread natural avalanche cycle triggered by strong to extreme wind loading event in the alpine. As well as an icefall triggered size 2.5 slab avalanche that failed on the mid-March interface, northwest of Meziadin Lake.Wednesday a natural avalanche cycle up to size 1.5 was reported on wind affected features, as well as skier triggered storm snow releases up to size 1. A natural cornice failure that released a size 1.5 slab was also reported from an east aspect in the Shames area. Read MIN report here.On Tuesday, there was a size 2 natural wind slab avalanche reported from a north aspect alpine slope. There were also several small (size 1), thin soft slab avalanches on recently wind-loaded features. A large (size 3) glide avalanche was reported from a N-NW slope below treeline. Additionally, steep south aspect slopes released loose wet avalanches in the afternoon.Last week, large persistent slab avalanches were reported on east to northeast aspects at all elevations, failing on the early-March and mid-March layers. There have been no reports of avalanches on these layers so far this week.

Snowpack Summary

Strong to extreme winds have created widespread wind affect in the alpine and at treeline. At lower elevations up to 10-20 cm of snow sits on a solid crust.In the south of the region, 70 to 100 cm of recent storm snow overlies two layers of surface hoar. The layers are most prominent on north to east aspects and were buried early-March and mid-March. In the north of the region, these layers are around 40 cm deep.Bellow this interface the mid-pack is generally well-settled and strong. However, shallower parts of the region, such as the far north, have weak sugary facets near the bottom of the snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
Strong to extreme winds and new snow have formed touchy wind slabs in leeward areas at treeline and in the alpine.  While natural activity has likely tapered off, expect these slabs to remain primed for human triggering.
Use caution in lee areas. Recent wind loading has created wind slabs.Be careful with wind loaded and cross-loaded slopes, especially near ridge crests and roll-overs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 7th, 2018 2:00PM

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