Avalanche Forecast

Issued: Dec 19th, 2013 8:41AM

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

ghelgeson, Avalanche Canada

Northwest Inland.

Forecasters are working with very little field data at this time. If you are traveling in the backcountry and have information, we'd love to hear about it! forecaster@avalanche.ca

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Synopsis: Upper NW flow brings significant precipitation to the North Coast over the next few days. This should result in a bit of a snow accompanied by strong winds for the Inland region.Friday: Freezing Level: 700m Precip: 2/4mm 4/8cm Wind: Lht gusting Strong, NW Saturday: Freezing Level: 700m Precip: Trace Wind: Lht gusting Strong, NWSunday: Freezing Level: 1800m Precip: Trace Wind: Mod gusting Extreme, SW

Avalanche Summary

A few small wind slabs just below ridge crest were reported on Dec. 15. No other avalanches have been reported. This likely speaks more to the lack of observations than actual conditions.

Snowpack Summary

We're relying on a shoe string worth of data for this forecast! There is significant variation in snow depths across the region. In the Smithers area the ski hill is reporting an 85 cm base. Treeline depths vary between 100 - 180 cm.It sounds like a bit of cold dry snow has fallen in the last two days. The weekend storm finished very warm, as a result a crust can be found near the snow surface below 1100m. The best guess is that the last storm produced around 10 - 50 cm of snow. This snow now overlies the layer of facets/surface hoar that sit above old wind slabs and melt-freeze crusts which were formed during the December cold/dry spell. We don't have great wind stations in the region, but the coast saw a lot of strong wind during the last storm & I suspect this region was similarly hammered by wind. The mid and lower snowpack is still structurally weak due to facets, potentially even depth hoar and an early season crust near the ground.

Problems

Wind Slabs

Watch for the development of a new batch of fresh sensitive wind slabs as the winds pick up on Friday.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Deep Persistent Slabs

Triggering an avalanche on the crust/facet combo is likely still possible, especially where the snowpack is thin and weak. Keep this lingering weakness in mind as you make terrain choices throughout your day.

Avoid convexities or areas with a thin or variable snowpack.>Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Be aware of the potential for large, deep avalanches due to the presence of buried crust/facet combo.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Dec 20th, 2013 2:00PM