Avalanche Forecast

Issued: Mar 9th, 2016 7:20AM

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

pmarshall, Avalanche Canada

Northwest Inland.

Very strong winds are expected with the approaching weather system. These winds could also push more snow into the Inland region than initially expected. As such, danger is elevated for Thursday.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

THURSDAY: Periods of snow â€“ 10-20 cm. The freezing level peaks near 1400 m but gradually lowers to valley bottom by the end of the day. Winds are strong from the W-SW. FRIDAY: Cloudy with sunny breaks. The freezing level is around 1200 m and winds are light to moderate from the SE. SATURDAY: Cloudy with sunny breaks. The freezing level is around 1000-1200 m and winds are light from the SE.

Avalanche Summary

There were no new reports of avalanches on Tuesday. A couple natural size 2 wind slabs were observed on immediate lee alpine slopes on Monday. One size 3 natural storm slab was observed in the Southwest corner of the region on Sunday. This slide probably occurred 1-2 days earlier. It released on a northeast aspect in the alpine. There were a handful of large persistent slab avalanches triggered on basal facets in the mountains north of Kispiox last week.

Snowpack Summary

Roughly 20-40 cm of snow has fallen in the past week, with the highest accumulations occurring in the southwest of the region. Strong to extreme ridgetop winds have shifted the new snow into hard or soft wind slabs in exposed terrain, adding to an ongoing wind slab problem. A layer of surface hoar from early January can be found in isolated locations between 60 and 140 cm down. There hasn't been any activity reported on this layer for a couple of weeks now and it is becoming less of a concern. In shallower areas the snowpack sits on a weak base layer of facetted snow. Recently, this layer has been active in the north of the region, responsible for several large avalanches in unsupported alpine terrain.

Problems

Wind Slabs

New snow combined with very strong and shifting winds will create deep and dense wind slabs in exposed terrain on a variety of aspects.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Deep Persistent Slabs

This next system could deliver a big enough punch to trigger very large avalanches on weaknesses near the bottom of the snowpack. Steer clear of big, steep slopes with variable snow depth.

Be aware of thin areas that may propogate to deeper instabilites.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Mar 10th, 2016 2:00PM