Avalanche Forecast

Issued: Jan 6th, 2014 4:00PM

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

Rupert wedgwood, Parks Canada

Jasper.

Careful snowpack evaluation and conservative decision-making is essential right now as the lingering deep instability will be with us for the foreseeable future.

Summary

Weather Forecast

A south westerly flow over the park with warming temperatures into Wednesday. Light amounts of precipitation and temperatures dropping to the mid teens overnight and single digits during the day. Stronger winds at ridge top elevations will stiffen the wind slabs and add to cornices.

Snowpack Summary

Up to 30cm of low density storm snow overlies existing wind slabs which in places has a very weak faceted basal layer. Below tree line the snow pack has very little support except in isolated open areas where wind slabs may exist. New windslabs have formed at upper elevations but lots of snow is still available for transport.

Avalanche Summary

Road patrols in the South end of the forecast area observed numerous size 3 slabs that failed on the basal facets and widespread smaller avalanches to sz 2 on all aspects in the alpine involving windslabs and loose dry avalanches.

Confidence

Freezing levels are uncertain on Wednesday

Problems

Deep Persistent Slabs

Storm snow and wind have overloaded the weak basal layers in several places and caused numerous large natural avalanches in the alpine. Cornice fall, smaller slides, and skiers in shallow areas all have the ability to trigger deeper instabilities.

Avoid steep, open slopes.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Wind Slabs

Recent storm snow and strong winds in the alpine are forming new windslabs at upper elevations.

Avoid freshly wind loaded features.Avoid ice climbs that are in terrain traps below large start zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Dry

There is lots of new snow plastered to steep rock and ice terrain. With the expected warming trend (and solar effect) over the next week, expect this terrain to shed this snow.

Sluffs may trigger deeper instabilities.Avoid travelling on ledges and cliffs where sluffing may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 7th, 2014 4:00PM