Avalanche Forecast

Issued: Dec 16th, 2012 4:00PM

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

mike eder, Parks Canada

Jasper.

Summary

Weather Forecast

A frontal system is expected to come through on Monday with a slight rise in temperatures and only limited snow flurries. Ridgetop winds will increase to moderate/strong starting from the South and shifting to the West by late afternoon. Tuesday will have sunny periods with cooler temperatures.

Snowpack Summary

There is great variation in depth and location of the wind slabs. These slabs appear to have bonded well to the old snow surface, with no new avalanches observed in the last week. Cornices are well developed. The raincrust laminate down in the lower 1/3 of snowpack is deteriorating into a facetted layer and did not respond to field tests.Â

Avalanche Summary

No new avalanches have been observed since Monday Dec 10.Â Wind slabs appear to have bonded well to the old snow surface.

Confidence

Problems

Wind Slabs

Pockets of wind slabs that vary in hardness are present on all open lee slopes. No new avalanches have been observed in the last week, 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

The November raincrusts are deteriorating into a facet layer that is not responding to field tests at this time.

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 17th, 2012 4:00PM