Avalanche Forecast

Issued: Dec 14th, 2015 4:00PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

Excellent ski conditions out there right now! Forecasters still have some uncertainty in the danger rating due to the spatial variability of the Dec. 3rd surface hoar layer. This is an unusual situation where the danger is highest below treeline

Summary

Weather Forecast

We are under the influence of a ridge of high pressure for the next few days. Expect to see clearing skies through the week, minimal snow and light NW winds. Temperatures will remain cool in the -10 to -20 range. No inputs to significantly change the danger rating or ski conditions are expected.

Snowpack Summary

In sheltered terrain between 1700 and 2150m, a 30-40 cm soft slab sits over the December 3rd surface hoar. This layer continues to produce whumphs and easy shears in many locations, especially in areas to the West with more snow. No other significant shears have been observed. In the alpine isolated wind slabs exist in immediate lee areas.

Avalanche Summary

Sunshine ski area avalanche control team reported triggering small soft windslabs in steep alpine terrain with explosives today. Otherwise no new avalanches observed.

Confidence

Problems

Persistent Slabs

A 30-40cm soft slab sits over the Dec 3 surface hoar in an elevation band between 1700 and 2150m. Continue to treat all steep open slopes below treeline with suspicion until you can rule out this weak layer.

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

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Wind Slabs

Small windslabs formed with the last storm and are slowly settling out. These were reactive with explosive triggers in the Sunshine area on Monday,

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 15th, 2015 4:00PM