Avalanche Forecast

Issued: Dec 13th, 2016 4:00PM

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

max darrah, Parks Canada

Jasper.

Intense ridge top transport observed today in the alpine. This Northwesterly wind will likely have produced some new windslabs, particularly on South aspects.

Summary

Weather Forecast

Temperatures to warm slightly before dropping again to -30 by Friday. No precipitation. Northwest winds to continue, making the alpine feel even colder. The intense ridgetop winds are expected to decrease in the next 48hours.Â

Snowpack Summary

Ongoing moderate Northwest winds redistributing cold snow, soft slab formation possible on lee features. Arctic cold temps have penetrated the shallow snowpack and are promoting facetting. Nov12 crust down 45 to 90cm and found between 2100-2600m on all aspects. Intense ridge top transport from the North reverse loading lee features in the alpine.

Avalanche Summary

Numerous loose dry avalanches on Westerly aspects up to Size 2 in Alpine terrain observed along the Icefields Parkway today. Recent shift of winds to the Northwest seem to have been the trigger for these events. One remotely triggered slab avalanche size1.5 was reported from the Boundary Glacier area on Monday, 2400m steep East facing planar slope.

Confidence

Problems

Loose Dry

Cold temps promoting facetting of upper snow pack. Expect loose dry avalanches from steep terrain.

Avoid travelling on ledges and cliffs where sluffing may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

Report of a remotely triggered size 1.5 windslab and extensive scouring in the alpine. Intense ridgetop transport observed on field trip today in the Columbia Icefield area likely producing some new windslabs in the alpine.

Avoid travelling in areas that have been reverse loaded by winds.

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

Elevations: Alpine.

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.

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 14th, 2016 4:00PM