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Avalanche Canada jsmith, Avalanche Canada

South Rockies Avalanche Forecast

Dec 8th, 2016 5:13PM

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

Lookout for stiff wind slabs in the alpine. Likely trigger spots are steep and rocky alpine terrain with a shallow snowpack.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Friday: Cloudy with isolated flurries / Light easterly winds / Weak inversion with a alpine high of -15 C.Saturday: Cloudy with scattered flurries / Light to moderate southerly winds / Alpine high -11 C.Sunday: Mostly cloudy with isolated flurries / Moderate southwesterly winds / Alpine high of -12 C.

Avalanche Summary

No recent avalanche observations have been reported in this region.

Snowpack Summary

Up to 30 cm of recent storm snow has buried old snow surfaces including surface hoar and old, stiff wind slabs. The cold temperatures will have promoted surface faceting, which probably means the top layer of snow is soft in most places. Treeline snow depths around Elkford are only around 60 cm. I suspect they are slightly higher in places like the Flathead, but generally conditions are lean. Threshold snow depths for avalanches have been exceeded in the alpine and at treeline, but not below treeline. In shallow areas, the snowpack is most likely facetted (sugary) throughout, and any crusts have probably broken down already. In deeper areas, you can probably find the mid-November crust buried under half a metre or so of snow.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1 - 2
Lingering wind slabs formed last weekend could still be reactive to human triggers in isolated terrain features. Changing wind directions may also reverse load normally windward slopes and catch you by surprise.
Use ridges or ribs to avoid pockets of wind loaded snow.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects:

All aspects.

Elevations:

Alpine.

Valid until: Dec 9th, 2016 2:00PM