Avalanche Forecast

Issued: Dec 30th, 2012 9:13AM

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

pgoddard, Avalanche Canada

South Rockies.

Summary

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Monday-Wednesday: Expect benign weather with light winds, alpine temperatures around -8 and no precipitation. It may warm up a bit on Wednesday, with the freezing level rising to 1400 m.

Avalanche Summary

Size 1-2 loose dry avalanches failed naturally on Saturday.

Snowpack Summary

Wind slabs may be found behind terrain breaks such as ridges, ribs and gully walls. A generally settled upper snowpack overlies two or more buried crusts. The December crust is found 70-140 cm below the surface and the November crust/facet layer is near the base of the snowpack. Recent snowpack tests have shown little reactivity on these layers, apart from in the Flathead Range near Fernie, where sudden results on the November crust and a large settlement were observed on Saturday. Although unlikely, there is a lingering possibility of triggering a deep avalanche, especially from thin snowpack areas. Check out the forecaster’s blog for more discussion on this.

Problems

Wind Slabs

Wind slabs may be found behind ridges, ribs and gully walls. In specific thin snowpack areas, it may be possible for a wind slab to trigger a failure on a deeply buried weak layer.

Be aware of thin areas that may propagate to deeper instabilites.>Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Dec 31st, 2012 2:00PM