Avalanche Forecast

Issued: Dec 29th, 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 potential will be in sheltered glades around treeline. This may be a good time to consider some of the larger ice climbs in the area.

Summary

Weather Forecast

A stable air mass is moving into the area which will bring light Northwest winds gusting to moderate at ridge tops in the afternoon. No significant precipitation is in the forecast for the next few days. Temperatures should rise during the day, but freezing levels will remain at valley bottom.

Snowpack Summary

Yesterday's moderate to strong SW winds built slab conditions on open tree line slopes and along ridge lines in the alpine. Winds have tapered off as a stable airmass moves in. The mid-pack is facetting in shallower areas, but remains strong around treeline. Northwest winds may redistribute some snow onto Southeast aspects near ridge tops.

Avalanche Summary

Small, loose snow avalanches continue to run from rock bands and steep alpine terrain. These slides have little mass and have not as yet triggered the wind slabs beneath them.� No natural slab avalanches were observed today.

Confidence

The weather pattern is stable

Problems

Wind Slabs

Moderate to strong westerly winds have created wind slab conditions on slopes and along ridge lines especially in the Icefields area. No avalanche activity has been observed on this condition, however, we have not tested the bonding strength.

Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Deep Persistent Slabs

On Wednesday, small natural slab avalanches to size 1.5 were observed on the basal facets in thin snowpack areas. Triggering is most likely to happen along edges of shallow pockets and from thin spots like rocks or trees.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 30th, 2012 4:00PM