Avalanche Forecast

Issued: Jan 4th, 2013 9:38AM

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

Avalanche Canada slemieux, Avalanche Canada

If you are traveling in an area and it starts to snow significantly, consider the danger ratings to be higher than posted.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Friday night and Saturday: The upper trough that left some precipitations in the Lizard range area gives way to a surface ridge of high pressure with cold temperatures (-10 C in the alpine), sunny with few cloud cover and strong Southwest winds. Another system arrives later during the day covering up the sky gradually and warming up temperatures slightly. Sunday: The system is moving across the region during the day bringing traces or no precipitation on the Eastern part of the region, light winds and warmer temperatures (-5 C in the alpine). Monday: Traces of precipitation could fall on the region accompanied by light winds from the West and temperatures cooling slightly again.

Avalanche Summary

A few natural and skier triggered slab avalanches up to size1.5 were reported in the Lizard Range region. Some sluffing was also observed off steep slopes in the alpine in the Lizard Range as well.

Snowpack Summary

Lots of depth and surface variability has been observed in the Crowsnest area of the region recently. Windslabs exist below ridge top on lee alpine and treeline slopes (North facing slopes) and wind pressed or rocky surface on wind scoured aspects (South facing slopes). Surface is also facetting in shallower snowpack areas. Cornices have also been growing and are a concern to professionals. It is also interesting to make a mental note for the future snowfall event that a surface hoar layer is growing at the surface in the below treeline band. The 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 ski/snowmobile tests have shown little reactivity on these layers, apart from in the Flathead Range near Fernie, where there is a lingering possibility of triggering a deep avalanche in specific thin, rocky snowpack areas.

Problems

Wind Slabs

An icon showing Wind Slabs
Windslabs could grow slightly below ridgetop and on crossloaded features with forecasted strong West winds.
Be aware of the potential for wide propagations due to the presence of hard windslabs.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Jan 5th, 2013 2:00PM