Avalanche Forecast

Issued: Dec 1st, 2012 8:59AM

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

triley, Avalanche Canada

South Rockies.

Some areas in the West of the region may have received more new snow recently. If your area has more than 30 cms of new snow in the alpine, then consider these ratings a little low.

Summary

Confidence

Fair - Due to limited field observations on Sunday

Weather Forecast

Overnight and Sunday: Light precipitation overnight should become very light by morning. Alpine temperatures should be about -8.0 and the freezing level should be down to the valleys. Winds should lighten and back to the SE. Expect broken skies in the East of the region.Monday: Overcast with light drizzle or wet flurries in the valleys. Alpine temperatures around -8.0 with strong SW winds at higher elevations. Tuesday: Western areas should get another warm pulse of moisture, maybe up to 15 mm. The East of the region may get considerably less moisture, and more wind.

Avalanche Summary

No new 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

New storm slabs have developed in the alpine that are 20-30 cms deep. Some pockets of wind slab may develop at higher elevations near ridge tops. The new snow has been reported as moist at treeline.

The new snow will require several days to settle and stabilize.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

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.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Dec 2nd, 2012 2:00PM