Avalanche Forecast

Issued: Dec 14th, 2016 3:56PM

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

Avalanche Canada rbuhler, Avalanche Canada

Wind slabs continue to be the primary concern. Watch for signs of recent wind loading and use extra caution in wind exposed terrain.

Summary

Confidence

Moderate - Wind speed and direction is uncertain

Weather Forecast

The cold Arctic air is expected to persist through the weekend. On Thursday, mostly cloudy conditions are expected with treeline temperatures around -15C and moderate outflow winds in the valleys. There is a chance of light flurries on Thursday in the south of the region. Friday and Saturday are currently expected to be mainly sunny with light to moderate alpine winds and treeline temperatures below -20C.

Avalanche Summary

On Tuesday, ski cutting and explosives triggered a few size 1 soft slab avalanches in wind loaded terrain features. These were 15-20 cm thick. A few size 1 loose dry avalanches were also observed in steep terrain.On Thursday, wind slabs may be reactive to human triggering in exposed terrain. With ongoing moderate outflow winds forecast, these wind slabs are expected to continue to build.

Snowpack Summary

Wind slabs may exist in isolated lee features below ridgetops but are not expected to be widespread due to relatively light wind speeds thus far. The cold temperatures have promoted surface faceting, which probably means the top layer of snow is soft in sheltered areas. Treeline snow depths around Elkford are only around 60 cm. 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 down around 50 cm. Below treeline, early season hazards such as stumps, rocks, and open creeks are still a major concern.

Problems

Wind Slabs

An icon showing Wind Slabs
Recently formed wind slabs may be reactive to triggering in immediately leeward terrain features. Ongoing outflow winds will continue to build these slabs. Watch for signs of recent wind transport and avoid areas where the surface snow feels stiff.
Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 15th, 2016 2:00PM