Avalanche Forecast

Issued: Jan 11th, 2015 9:18AM

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

Avalanche Canada ghelgeson, Avalanche Canada

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Purcells.

Variable reactivity of the mid-December crust/surface hoar interface is driving significant uncertainty. The solution is easy though: Stay disciplined and continue to seek out the most conservative terrain.

Summary

Confidence

Fair

Weather Forecast

An upper ridge continues to shift the storm track into the Alaskan Panhandle.  No new snow is expected for the three day forecast period.  Winds are expected to remain very light out of the W/NW at treeline and moderate NW at ridgetop.  The freezing level looks to remain at Valley Bottom until Wednesday afternoon when it is expected to rise as warm SW air begins to invade the province.

Avalanche Summary

No new avalanche activity to report.

Snowpack Summary

There is a great deal of variability across the region. The West and South have received up to 60 cm of storm last week which was quickly followed by high freezing levels and warm air up into the alpine which has resulted in a breakable surface crust. The North and East of the region have had 20-30 cm of cold dry new snow which has since been redistributed into ageing wind slabs, while large surface hoar is growing in sheltered areas. Deeper in the snowpack there is a persistent weak layer of surface hoar and crust that is now down about 30-80 cm. Recent snowpack tests on the West side of the range produced easy resistant results down 25 cm in the recent storm snow, and moderate to hard but sudden results down 80-90 cm on buried surface hoar sitting on a crust.

Problems

Persistent Slabs

An icon showing Persistent Slabs
A persistent weakness buried mid-December is spotty in distribution and reactivity, but remains problematic at and below treeline where the snowpack structure is primed for human triggering.
Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 5

Valid until: Jan 12th, 2015 2:00PM

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