Avalanche Forecast

Issued: Dec 22nd, 2012 4:00PM

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

garth lemke, Parks Canada

Jasper.

Ice climbers be aware of slopes where loose avalanches and terrain traps could have significant consequences.

Summary

Weather Forecast

A weak low may pass through area Sunday into Monday but the Arctic air will continue to dominate with cold temperatures, sunny breaks, light flurries, and light N winds. A possible temperature inversion may develop over the next few days.

Snowpack Summary

Thursday's 10 cm of new snow in the Icefields area has buried previous wind slabs on NE aspects, tree line and above. The mid-pack remains supportive however it is quickly loosing strength in shallow locations.

Avalanche Summary

Friday's avalanche control work at the Icefields released several loose size 2 avalanches in thin steep snowpack areas below treeline. Natural avalanches have been limited to similar characteristics, steep, rocky, thin areas creating loose avalanches.

Confidence

The weather pattern is stable

Problems

Wind Slabs

Thursday's 10 cm of snow has buried the wind slabs which formed earlier this week. Winds have shifted from S to N. Watch for reverse loading patterns.

The recent snow may now be hiding windslabs that were easily visible before the snow fell.Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Deep Persistent Slabs

The strong mid-pack above this weakness is slowly loosing its strength. This issue is more prevalent in shallow snow pack areas being likely trigger spots.

Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Dec 23rd, 2012 4:00PM