Avalanche Forecast

Issued: Jan 8th, 2015 4:34PM

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

tim haggarty, Parks Canada

Waterton Lakes.

We emerge from the latest storms and avalanche cycle with a bit more confidence in the snowpack but are still wary of high elevation and shallow snowpack areas. Surface crusts have hurt the ski quality below treeline.

Summary

Weather Forecast

Warming up and strong SW winds for Fri with a strong temperature inversion. Clouding over with temperatures dropping to the minus teens range for Saturday. Winds will drop off on Sunday becoming light from the NE. A trace of snow on Saturday and Sunday but not more than a few a few centimeters.

Snowpack Summary

The 25 to 50cm storm slabs are now capped by a variety of crusts below treeline and on solar aspects and have been influenced by variable winds. The Dec 13 crust is now 60 to 120cm deep and continues to produce planar shears within the facets above the crust.

Avalanche Summary

Warm temperatures and strong winds induced a widespread cycle of storm slabs on all aspects and elevations Wednesday. Some of these events ran from ridge crest to valley bottom however with our first look around today we saw no evidence of activity on the persistent weak layer. There have however, been reports of activity on the PWL from neighbors.

Confidence

Due to the number of field observations

Problems

Storm Slabs

Where there are no surface crusts these slabs may remain available for triggering particularly where they have been influenced by the wind.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Continue to watch for this layer which has proven to be extremely variable. Areas where these slabs are thin may should raise added caution.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 11th, 2015 4:00PM