Avalanche Forecast

Issued: Jan 12th, 2013 4:00PM

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

garth lemke, Parks Canada

Jasper.

Winds have affected the recent storm snow. Upside down powder condition making for challenging skiing. Weather models may be overestimating warming trend on Monday and Tuesday but still a few days away, could be a game changer.

Summary

Weather Forecast

Sunday: Light flurries, trending warmer, 1500m light westerly winds but 50km/hr NW at 3000m. Monday: 5cm snow, warm temperatures but remaining below 0, 50-80km/hr NW ridgetop winds and stronger winds at higher elevations. A little valley bottom freezing rain. Tuesday: Above normal temperatures, potentially +6 in town, continued strong alpine winds.Â

Snowpack Summary

Up to 30 cm of low density storm snow fell on Wednesday but nothing since then. Winds are forming it into slabs alpine and exposed treeline locations. Low elevations the snow remains thin and facetted. Tree line and above its thicker and supportive. A buried a surface hoar layer from Jan 6 is lurking but has yet to become an issue.

Avalanche Summary

Thursday's explosive control on low elevation targets released several size 2 slabs and loose snow avalanches. Natural activity has remain limited. No natural activity was noted today; however, forecasters observed pockets of thin windslabs, minor whumphing and cracking, which should be continually assessed as it seems to be getting worse.Â

Confidence

Wind speed and direction is uncertain on Sunday

Problems

Wind Slabs

Last Wednesday's 30cm storm is rapidly evolving into a windslab with the influence of alpine winds. This may cover a buried surface hoar from Jan 6 yet its remained unreactive. Minor whumphing and upside down powder was noted today in the alpine.

Be cautious as you transition into wind affected terrain.Make observations and assess conditions continually as you travel.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Dry

Where the wind has not affected the snow, 30cm of unconsolidated storm snow is sluffing out of steep terrain. They can pick up enough mass to be a concern to skier and climbers particularly when terrain traps are involved.

The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 13th, 2013 4:00PM