Avalanche Forecast

Issued: Dec 15th, 2012 4:00PM

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

mike eder, Parks Canada

Jasper.

Good skiing can be found in sheltered glades around treeline.

Summary

Weather Forecast

Predominantly light to moderate SW winds with snow flurries that will produce minimal accumulations. Monday will have a slight warming trend with light winds coming from the South to Southeast.

Snowpack Summary

There is great variation in depth and location of the wind slabs. They continue to build and harden from gusting moderate to strong SW winds.�These slabs appear to have bonded well.� In windswept areas in the alpine and at tree line, the November rain crust has been exposed along with dirt and rocks.� Cornices are well developed.

Avalanche Summary

No new avalanches have been observed or reported since the end the cycle that ended on Monday.� In that cycle, slab avalanches to size 3 were observed on NE aspects at alpine and tree line elevations, several stepped down to the basal facet layer.� Large cornice failure triggered large avalanches on the basal facet layer as well.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Pockets of wind slabs that vary in hardness are present on all open lee slopes. No new avalanches have been observed and field tests show that these slabs have bonded well in most locations.

Choose well supported terrain without convexities.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Deep Persistent Slabs

Cornice failures have triggered this weakness on SE to NE aspects in the alpine.

Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 16th, 2012 4:00PM