Avalanche Forecast

Issued: Jan 19th, 2016 8:24AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs.

Avalanche Canada rbuhler, Avalanche Canada

Highly sensitive storm slabs are everywhere. Conservative terrain selection is essential for safe travel.

Summary

Confidence

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

Weather Forecast

Unsettled conditions are expected for Wednesday with 2-10cm of new snowfall possible in the morning and sunny breaks possible in the afternoon. Freezing levels are expected to be 800-1000m and alpine winds should be mainly moderate from the south. A weak storm system is expected to bring 10-15cm of new snow on Thursday with freezing levels around 800m and strong southerly winds in the alpine. This storm is expected to continue on Friday with another 10-20cm by possible by Friday evening.

Avalanche Summary

On Monday, numerous avalanches were reported in the region. Several natural avalanches were reported including widespread activity up to size 2 north of Stewart and several natural avalanches size 2.5-3.5 north of Terrace. Several skier triggered avalanches were reported which were mostly size 2. This includes a few remotely and sympathetically triggered avalanches which were mostly triggered from 10m away. Explosives also triggered numerous avalanches. The large majority of this avalanche activity released on the Jan 9 surface hoar layer down 30-80cm. The majority of these avalanches were reported on north aspects but there were avalanches on all aspects and elevation bands.

Snowpack Summary

Recent storm snow amounts have been variable across the region, but generally 40-60cm have accumulated since January 9 when the most recent surface hoar was buried. Below that is another surface hoar layer down 60-80cm. Both are showing a high propensity for propagation with remote triggering and whumpfing, as well as sudden shears with snowpack tests in the easy to moderate range. Deeper persistent weaknesses buried in December have the potential to wake-up to heavy loading, rapid warming, or avalanches stepping-down. Recent strong to extreme southeast winds have loaded leeward features on west through north aspect slopes.

Problems

Storm Slabs

An icon showing Storm Slabs
Storm slabs are primed for human triggering on all aspects and at all elevations. Remote triggering and widespread propagation makes hazard particularly tricky to manage.
Stick to simple terrain and be aware of what is above you at all times.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Use conservative route selection, stick to low angled terrain with low consequence.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Valid until: Jan 20th, 2016 2:00PM