Avalanche Forecast

Issued: Jan 7th, 2014 8:46AM

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

jlammers, Avalanche Canada

Northwest Coastal.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain on Wednesday

Weather Forecast

Wednesday: Light to moderate snowfall / Moderate southwest winds / Freezing level at 700mThursday Heavy snowfall arriving late in the day / Strong to extreme southerly winds / Freezing level at 600mFriday: Light to moderate snowfall / Moderate westerly winds / Freezing level at 600m

Avalanche Summary

In recent days a few slab avalanches to size 3.5 were noted in alpine terrain in the far north of the region. They were suspected to have failed on basal facets. I would expect a new round of storm slab activity with weather forecast for the next few days.

Snowpack Summary

In general the snowpack seems shallower and more faceted in the northern part of the region, and deeper with more wind slab problems in the south. At 1300m on an east aspect in the Shames area the height of snow was about 190cm. Very light amounts of new snow now overlie a variety of old surface which include: settled storm snow, surface hoar in sheltered locations, and wind slabs at upper elevations. About 30cm below the surface you may find several laminated thin melt/freeze crusts. Moderate sudden planar shears were experienced in snowpack tests down about 40 cm in a weak facet layer that is sitting above a melt/freeze crust from Christmas. Deeper early December facetted crystals were found to be rounding and gaining strength in this area.

Problems

Wind Slabs

New snow and wind will likely create fresh new windslabs. The new snow will also hide older windslabs formed by northwest winds a few days ago.

Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

A weak layer of buried facets near the ground continues to be a concern in the North of the region. Try to get local knowledge if you are traveling to new areas.

Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>Avoid shallow snowpack areas where triggering is more likely.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Jan 8th, 2014 2:00PM