Avalanche Forecast

Issued: Feb 5th, 2015 4:00PM

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

deryl kelly, Parks Canada

Jasper.

It's going to be Heads up Hockey out there on the Jan ice layer. Snow fall amounts may be in excess of 20cms for friday morning with more expected thought the weekend!

Summary

Weather Forecast

All the weather models are in agreement (a rare occurrence in itself) and so far, precip models are proving correct. It's snowing out my window as I write. If this pattern of weather truths continues we should find up to 20cms of new snow on the ground Friday morning and much more to come. Keep your eye on the forecast through the weekend.

Snowpack Summary

With the first input of new snow we likely will find areas of new buried surface hoar. That is sitting on a further 15cm over the Jan rain crust found on all aspects up to 2100m. Wind slabs forming on lee aspects, cross loaded features and open areas.

Avalanche Summary

Road patrols reporting poor visibility and no new avalanches observed.

Confidence

Problems

Storm Slabs

The Jan 30th interface has proven reactive with light inputs of new snow. This new storm will only continue to overload that layer. Also, treat recently re-loaded bed surfaces with caution as this layer will not go away easily.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Choose ice climbs that are not exposed to avalanches from above.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

Intense loading continues with a new input of snow on lee and cross loaded features at all elevations.

Avoid steep lee and cross-loaded featuresMinimize exposure during periods of heavy loading from new snow, wind.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

This layer remains a concern in isolated areas above treeline and may be triggered by large loads such as cornices, surface slides or from shallow areas by skiers. The entire snowpack throughout the forecast region is sitting on 20cm of depth hoar.

Caution around convexities or areas with a thin or variable snowpack.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 6th, 2015 4:00PM