Avalanche Forecast

Issued: Jan 14th, 2016 8:28AM

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

Avalanche Canada triley, Avalanche Canada

These danger ratings are for areas with less than 20 cm of recent storm snow. If your area has had higher snowfall amounts, these danger ratings may be a bit low.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

A weak ridge of high pressure is building over the interior ranges. Some light flurries can be expected overnight with moderate alpine winds from the northwest. Alpine temperatures should be around -10 on Friday with periods of broken sky or scattered cloud. There may be some solar warming on steep southerly aspects. The next storm is forecast to move inland from the coast on Saturday. There is some uncertainty regarding the timing and intensity of this next storm. Cold air and high pressure to the east may slow down the system resulting in about 3-5 cm by Sunday morning. Light snow should continue during the day on Sunday.

Avalanche Summary

Some small wind slabs size 1.0 were reported on Thursday morning from the north of the region. These wind slabs were the result of recent moderate northwest winds in the alpine, and they were 10-15 cm deep. On Wednesday a skier remotely triggered a wind slab from 30 metres away that was size 1.5 and the crown was 10-20 cm deep. Also on Thursday in the center of the region we had a report of numerous wind slabs skier controlled to size 1.0 on steep unsupported terrain at treeline. Conditions have been reported to be very different from the Selkirk mountains to the west, where much more storm snow has accumulated.

Snowpack Summary

Light and dry new snow has been transported into stiff wind slabs that are 10-20 cm deep in the alpine and at treeline.  The upper snowpack is generally loose and unconsolidated in sheltered areas, however there is now 30-40 cm sitting on a mix of surface hoar, facets, and sun crusts that were buried January 4th. Some operations continue to track buried surface hoar from early December. While test results on deeply buried surface hoar continue to show planar results when hard forces are applied, there have not been any avalanches reported failing on this layer. I have removed the persistent weak layer problem from the front page, and we will continue to monitor reports from operators in this region. The mid and lower snowpack is generally well settled and strong.

Problems

Wind Slabs

An icon showing Wind Slabs
New wind slabs have formed in the alpine and at treeline. These slabs may be stiff and allow for long propagations. New cornice growth may be fragile and fall off naturally with continued wind loading.
Avoid freshly wind loaded features.>Stay well to the windward side of corniced ridges.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

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