Avalanche Forecast

Issued: Jan 11th, 2016 8:54AM

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

Avalanche Canada jlammers, Avalanche Canada

Variable conditions exist across the region. Be your own forecaster and make observations continually as you travel.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Wednesday

Weather Forecast

On Tuesday expect overcast skies and trace amounts of new snow. By Wednesday morning, light snowfall will develop and continue until Thursday morning bringing 5 to 8cm of new snow. Ridgetop winds associated with the snowfall will be strong and southwesterly. Freezing levels may peak at about 1200m on Wednesday, but should otherwise remain at or near valley bottom for the rest of the forecast period.

Avalanche Summary

Explosives control on Saturday triggered a size 1 wind slab in the south of the region. No other recent avalanches have been reported in the South Rockies region. Several avalanches were reported in the Lizard/Flathead region on Thursday and Friday. The primary problem in that region is wind slabs failing on the early January surface hoar layer. Similar conditions may exist in some parts of the South Rockies.

Snowpack Summary

The Avalanche Canada field team has been finding variable conditions across the region. East of Crownest Pass the snow surface is now widely wind affected. Extensive scouring has been reported in some areas and and stiff wind slabs exist in lee features at treeline and in the alpine. In areas that have seen less wind, recently formed wind slabs are likely softer, deeper and may overlie weak surface hoar crystals which formed at the start of January. In either case, snow pit tests in wind loaded features show recently developed slabs are failing under moderate loads and can propagate over wide distances. The early December crust can be found down around 60-90cm. It is not currently expected to pose an avalanche problem but could wake-up in the future with substantial warming or heavy snow loading.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent tests suggest that wind slabs may be triggered by riders in the alpine and at treeline.  Watch out for hard slabs in heavily wind affected areas and deeper soft slabs sitting above surface hoar in more wind sheltered areas.
Be aware of the potential for wide propagations due to the presence of hard windslabs.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 12th, 2016 2:00PM