Avalanche Forecast

Issued: Dec 29th, 2013 4:00PM

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

garth lemke, Parks Canada

Jasper.

Happy holidays! Don't let your guard down with triggering the deep basal weakness. It remains unpredictable.

Summary

Weather Forecast

Expect 5-10cm from Sunday evening into Tuesday with seasonal temperatures. Winds will be light, gusting moderate Westerlies at higher elevations. Unsettled weather the next few days.

Snowpack Summary

The light precipitation amounts this weekend was not enough to alter the snowpack. It remains shallow with a variably distributed deep persistent slab overlying weak basal layers of depth hoar, crusts, and facets. Windslabs of various thicknesses continue to form in lee locations at treeline and above areas. Below treeline remains unsupportive.

Avalanche Summary

Saturday, four slab avalanches size 2.5-3 was observed in the alpine on a West aspect in shallow rocks, and steep unskiable terrain at 2700m running on basal weakness. The avalanches were restricted to a small zone between Boundary peak and Panther falls along the Parkway. Visibility was poor on Sunday.

Confidence

Forecast snowfall amounts are uncertain on Monday

Problems

Deep Persistent Slabs

Expect this layer to persist for a long time. Due to its unpredictable nature, use conservative choices as triggering this layer could have severe consequences. Shallow locations are likely trigger spots. Generally, everything is shallow right now.

Avoid steep, open slopes.Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

New snow over the weekend and winds will add to the wind slab development and hide it in some cases. Check for freshly loaded spots where a pocket of this instability would exist. Iceclimbers be cautious of crossloaded gullies and terrain traps.

Caution in lee and cross-loaded terrain near ridge crests.Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 30th, 2013 4:00PM