Avalanche Forecast

Issued: Dec 21st, 2015 4:20PM

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

Conrad Janzen, Parks Canada

Banff Yoho Kootenay.

Enjoy the great ski conditions over the Christmas Holidays!

Summary

Weather Forecast

A westerly flow with light alpine winds continues through Tuesday and Wednesday with clearing skies and only trace amounts of snow. Temps will drop with highs near -4'C and lows of -17'C at tree line on Tuesday.

Snowpack Summary

10-20cm of recent snow with Light to Moderate SW winds has formed isolated wind slabs in immediate lee areas in the alpine. The Dec 3 surface hoar is 40 to 70cm deep. Shears persist on this layer in some locations between 1700 and 2150m, however it is becoming less reactive in most places.

Avalanche Summary

Some small loose dry avalanches have been observed in very steep alpine terrain. Local ski areas were able to trigger small wind slabs up to size 1 in the alpine with avalanche control. No new natural slab avalanches have been observed.

Confidence

Due to the number of field observations

Problems

Wind Slabs

Isolated slabs soft slabs are present in immediate lee areas in the alpine. Fragile cornices have also been reported.

Use caution in lee areas. Recent wind loading has created wind slabs.Use safe ski cutting techniques before entering ski run.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

The slab above this layer has not been very reactive recently however snow pack tests continue to produce sudden shears in some areas. Dig down to identify and test this layer before committing to in steep, open or convex terrain below tree line.

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

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 22nd, 2015 4:00PM