Avalanche Forecast

Issued: Nov 30th, 2012 9:19AM

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

Avalanche Canada triley, Avalanche Canada

Watch for conditions that change with elevation. There may be significantly more storm snow at alpine elevations.

Summary

Confidence

Poor - Due to limited field observations for the entire period

Weather Forecast

Overnight and Saturday: The freezing level should start to drop down to near the valley bottoms after a cold front moves through to the East. Alpine winds should continue to be moderate from the SW with gusts to strong later in the day. Expect 5-10 mm of precipitation that should fall as snow in most of the region overnight, and another 5 mm during the day Saturday.Sunday: It should be cooler and drier with light winds during the day on Sunday. Expect -7.0 in the alpine, with light southerly winds.Monday: The next wave of moisture is expected to make its way inland from the coast during the day. Poor confidence in amounts and timing, stay tuned we should know more tomorrow.

Avalanche Summary

No recent avalanche observations. No signs of whumphing or cracking were observed in the Harvey Pass area.

Snowpack Summary

A report from near Harvey Pass tells us that there is about 25 cms of storm snow that is "damp" at treeline and the ski penetration is only about 20 cms. The November crust was found to be buried down about 60 cms and was associated with a layer of facets either directly above or below. Light winds were not transporting much snow in this area. Alpine elevations may be quite different, as most of the recent precipitation has fallen as snow. We are hoping that the storm snow will bond well as temperatures cool, this may still take a day or two.

Problems

Storm Slabs

An icon showing Storm Slabs
Old wind slabs may continue to linger on steep slopes that are not well supported by the terrain below. These windslabs are likely to be buried by new storm slabs in the next few days. Storm slabs may take a few days to bond to the old surface.
Be alert to conditions that change with elevation.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
We have not heard of any new releases on this early season rain crust. The new storm snow may create enough of a load to activate this layer. Look for signs of deep releases on steep terrain in the alpine during the storm.
Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Dec 1st, 2012 2:00PM

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