Avalanche Forecast

Issued: Jan 25th, 2016 8:14AM

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

Avalanche Canada bcorrigan, Avalanche Canada

Wind slabs are a major concern right now. Be extra cautious in areas affected by the wind.

Summary

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

Partly cloudy with sunny periods through the forecast period as the South Rockies comes under the effects of a high pressure ridge centered over the interior of BC. Light flurries possible, but no significant precipitation in the forecast for the next three or four days. Freezing levels will be at valley bottom overnight and may rise to 1500 metres Monday afternoon, dropping to 1000 metres Tuesday night, then rising to 1500 metres Tuesday.

Avalanche Summary

East of the divide, there have been reports of skier controlled and natural avalanches up to size 2 in the recent storm snow. Naturals up to size 2 also reported on the East Slope. Reports from the western part of the region tell of numerous large natural avalanches as well as a size 1, loose-wet avalanche below tree line that failed on a rain/temperature crust down 20 cm. Operators have reported impressive results with explosives, up to size 3. South West winds continue to transport the snow at tree line and above into touchy wind slabs.

Snowpack Summary

Recent storms with strong southwest winds have redistributed the snow at tree line and above. Wind slabs have formed lee on slopes, and A crust that formed in early December has reappeared with recent loading, east of Crowsnest Pass. In general the new snow overlies scoured surfaces or hard stubborn wind slabs from last week. The mid and lower snowpack are getting stronger and settling well in these areas. West of the divide there's a mix of weak crystals around 30 to 50cm below the surface. This layer is a combination of surface hoar, facets and a hard crust that formed on steep solar aspects. Additional snow load will add to the size and reactivity of the developing persistent slab. About 60 to 80cm below the surface there is surface hoar layer which formed in December. Although no avalanches have been reported on this layer, it continues to produce sudden planar results in snowpack tests and could come into play with a large trigger such as a cornice, or simply additional storm loading. All areas have received extensive wind activity around tree line and above.

Problems

Wind Slabs

An icon showing Wind Slabs
Light to moderate south west winds will continue to redistribute new snow at tree line and above, forming touchy wind slabs
Be aware of the potential for wide propagations due to the presence of hard windslabs.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Avoid slopes with glide cracks.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
A small wind slab avalanche could produce enough mass to trigger a deeper instability
Use extra caution on open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 26th, 2016 2:00PM

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