Avalanche Forecast

Issued: Dec 17th, 2015 4:00PM

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

Ian Jackson, Parks Canada

Banff Yoho Kootenay.

We should get a small storm on Friday which will refresh ski conditions, but not enough to change the avalanche danger greatly. Remain vigilant with routefinding below treeline where the Dec. 3rd Surface Hoar may be lurking!

Summary

Weather Forecast

The ridge of high pressure will start to break down Friday morning. Friday afternoon into Saturday morning, a system will dump 5-10 cm at upper elevations with winds switching to moderate from the SW and freezing levels staying at valley bottom. Saturday and Sunday will be partly cloudy with light precipitation and light west winds.

Snowpack Summary

In sheltered terrain between 1700 and 2150m, 30-40 cm of facetted snow sits over the December 3rd surface hoar. Easy to moderate shears found on this interface. No other significant shears have been observed in the snowpack. There is approximately 1 meter of snow at treeline,

Avalanche Summary

No new avalanches observed in the last few days.

Confidence

Due to the number and quality of field observations

Problems

Persistent Slabs

A 30-40cm soft slab sits over the Dec 3rd surface hoar in an elevation band between 1700 and 2150m. This slab has facetted out in many areas, but watch out in areas where previous wind may have formed a denser slab above this layer.

Dig down to find and test weak layers before committing to a line.Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 2

Valid until: Dec 18th, 2015 4:00PM