Avalanche Forecast

Issued: Dec 14th, 2016 4:00PM

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

garth lemke, Parks Canada

Jasper.

Intense ridge top transport occurred Tuesday in the alpine. The Northwesterly wind will likely produce some new windslabs particularly on Southerly aspects.

Summary

Weather Forecast

Thursday and Friday temperatures will hover between -20 to -30 with light North winds and clear skies. No precipitation expected for sometime. It might start to warm up on Sunday.

Snowpack Summary

Tuesday's moderate Northwest winds redistributed snow with soft slab formation possible on lee features. There was intense ridge top transport from the North in the alpine on Tuesday. Cold temps are promoting facetting throughout the snowpack. Nov12 crust down 45 to 90cm and found between 2100-2600m on all aspects.

Avalanche Summary

Nothing new noted on Wednesday's road patrol. Visibility was good. Tuesday numerous loose dry avalanches on Westerly aspects up to Size 2 in Alpine terrain along the Icefields Parkway. One remotely triggered slab avalanche size1.5 was reported from the Boundary Glacier area on Monday, 2400m steep East facing planar slope.

Confidence

Wind effect is extremely variable

Problems

Wind Slabs

Report of a remotely triggered size 1.5 windslab from Monday. Intense ridgetop transport and scouring from North winds observed on Tuesday's field trip in the Icefield area likely producing some new windslabs in the alpine.

Avoid travelling in areas that have been reverse loaded by winds.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Cold temps promoting facetting of upper snow pack causing it to loose internal cohesion. Expect loose dry avalanches from steep terrain.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The Nov crust is down 40-90cm and is beginning to facet out, lose strength and cohesion. There has been recent activity on this layer and requires respect. Consequences would be severe if triggered.

Be cautious in shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 15th, 2016 4:00PM