Avalanche Forecast

Issued: Jan 21st, 2018 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Given the recent snow and wind loading, there has been a surprising lack of avalanche activity. Until the snowpack adjusts to this new load conservative terrain choices are in order.

Summary

Confidence

Moderate -

Weather Forecast

The next couple of days will be partly cloudy with a chance of very light flurries. Winds will be strong from the west or south-west with temperatures near -10Â°C. Some snow is the forecast for late Wednesday and into Thursday with accumulations near 10cm.

Avalanche Summary

A few new size 2 slab avalanches were observed in the past 48hrs. These avalanches occurred in steeper Treeline areas failing down 30-40cm. In addition, a few small loose dry avalanches have occurred over the past 2 days in steep Alpine and Treeline terrain.

Snowpack Summary

Yet another day of strong winds coupled with as much as 25cm of snow in the past few days has led to continued wind slab development in the Alpine and open areas at Treeline. At 2250m and below there are now 3 layers of buried surface hoar, which is very unusual for the Rockies. These are referred to as the Jan 18th, Jan 6th and Dec 15th surface hoar layers, down 25, 50 and 100cm respectively. Recent snowpack stability tests indicate that all these layers are reactive, with the Jan 6th and Dec 15th layers the most concerning as there is now sufficient overlying slab to be an avalanche problem. The November crust layers are still on our radar, but still do not appear to be reactive at the moment.

Problems

Wind Slabs

On-going strong winds continue to build widespread wind slabs in the Alpine & open Treeline areas. These slabs are now found everywhere at upper elevations except in windward terrain where the ridges have been stripped down to bare rock.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Avoid steep lee and cross-loaded slopesAvoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Persistent Slabs

Forecasters are tracking 3 buried layers of concern (click on "Details" for more), which are variable in their distribution in both elevation and aspect. Due to high variability it is important to dig frequently to evaluate the layers.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.Avoid convex rolls at and below treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Jan 22nd, 2018 2:00PM