Avalanche Forecast

Issued: Jan 16th, 2016 8:41AM

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

Avalanche Canada rbuhler, Avalanche Canada

Light snowfall with strong to extreme southwest winds are expected to form new wind slabs on Sunday.  Use extra caution in wind-affected terrain and watch for signs of wind loading.

Summary

Confidence

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

Weather Forecast

A storm system is expected to reach the region Sunday morning. 5-10cm of new snow is expected by Sunday night. Alpine winds are expected to be strong to extreme from the southwest and freezing levels are forecast to reach around 800m in the south of the region. The stormy conditions should ease on Monday but light snowfall may continue during the day. Alpine winds should progressively ease to become moderate from south. Freezing levels are expected to hover around 800m in the south of the region. Another weak storm system is currently being forecast for Tuesday.

Avalanche Summary

No new avalanches were reported on Friday.  On Thursday, a couple of size 2 wind slab avalanches were reported from steep northwest aspects in the alpine.  These occurred in the upper Kispiox area and were typically 40cm deep slabs. In the north of the region on the border of the Northwest Coastal region we had a report of remotely triggered avalanches up to size 1.5 in the alpine and at treeline.

Snowpack Summary

The region has a mix of wind slabs and developing storm slabs. In higher snowpack areas in the northwest of the region, the storm slab has become reactive to human triggers. In most other areas the wind slabs are thin and stiff. Buried surface hoar is layered through the thin snowpack, and cool temperatures as well as limited loading have preserved these weak layers. The mid pack that was reported to be well settled may have now facetted in the shallower areas, and the deeper basal layers are almost certainly facetted and weak. We have not heard of any full depth releases on weak basal layers yet.

Problems

Wind Slabs

An icon showing Wind Slabs
New wind slabs are expected to form on Sunday with snowfall and strong SW winds.  Old stiffer wind slabs may also still be lingering around ridge crests.
Use ridges or ribs to avoid pockets of wind loaded snow. >Be aware of the potential for wide propagations due to the presence of hard windslabs. >Be careful with wind loaded pockets, especially near ridge crests and roll-overs. >

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 17th, 2016 2:00PM