Avalanche Forecast

Issued: Dec 27th, 2015 4:00PM

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

deryl kelly, Parks Canada

Jasper.

Summary

Weather Forecast

The coming high pressure system (expected Tuesday and dominating the rest of the week) will displace a minor low from the interior. Increasing cloud cover and light flurries expected overnight and into the day Monday; about 5-10cms. Winds continue to be gusty in open areas, shifting overnight from the SE to W. Temps moderating to around -10 to -15.

Snowpack Summary

Supportive and well settled snowpack above 1700m. Thin wind slabs in the alpine on the lee side of wind exposed terrain. Snowpack continues to facet with recent cold temperatures losing some overall depth as it drys and settles. The base of the snowpack is weakening from the cold but thus far the mid-pack is still bridging this growing weakness.

Avalanche Summary

Small loose snow avalanches in steep isolated areas. Observed below tree-line where the snowpack is shallow.

Confidence

Problems

Wind Slabs

Wind slabs can be expected to be most developed in the alpine with some redistribution and reverse-loading to happen as the winds shift 180 degrees.

Caution in lee and cross-loaded terrain near ridge crests.Avoid steep slopes below cornices.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

The facetting process is weakening the mid-pack from the top down and bottom up. This situation would make it possible to trigger the weakness at the base of the snowpack as the support underfoot shrinks. Watch for this in shallower areas.

Be cautious in shallow snowpack areas where triggering is more likely.Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 28th, 2015 4:00PM