Avalanche Forecast

Issued: Dec 18th, 2012 4:00PM

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

mike eder, Parks Canada

Jasper.

The best skiing can be found in wind sheltered glades around treeline.

Summary

Weather Forecast

A low pressure system will begin to move through on Wednesday afternoon with light snow flurries and moderate to strong Southwest ridgetop winds. Overcast skies and snow flurries will continue into Thursday, but will not amount to a lot of new snow. Temperatures will remain cold as a touch of arctic air influences the forecast area.

Snowpack Summary

The snowpack in the alpine and treeline is supportive, but new snow is needed soon to maintain this strength. Other snow observations in the alpine around the Columbia icefields indicates hard slabs and soft slabs of various thickness, but no propagation apparent with skier traffic.

Avalanche Summary

Several slab and loose avalanches to size 2 occurred on alpine solar aspects originating out of steep rock bands and initiating cross loaded gully features in the Icefields area today.

Confidence

on Wednesday

Problems

Wind Slabs

Moderate test results at treeline in the Portal creek area occurred on a Southeast facing 35 degree slope below a 25cm wind slab.

Choose well supported terrain without convexities.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Deep Persistent Slabs

The November rain crusts are deteriorating into a facet layer that is not responding to field tests at this time. A consolidated midpack is providing bridging strength over this layer and the basal facets.

Conditions are greatly improved, but be mindful that deep instabilities are still present.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 19th, 2012 4:00PM