Avalanche Forecast

Issued: Jan 11th, 2013 4:00PM

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

garth lemke, Parks Canada

Jasper.

Its cold but the skiing is good. Watch for wind affects where it converts the storm snow into a slab condition.

Summary

Weather Forecast

Saturday: mainly sunny, light to moderate alpine winds, frigid temperatures. Sunday: mixed clouds, light flurries, frigid temperatures. Monday: Scattered flurries and warming trend.

Snowpack Summary

Up to 30 cm of low density storm snow fell on Wednesday. Winds have yet to move it around. Low elevations it sits on a facetted thin snowpack. In tree line its on thicker supportive mid-pack. In wind exposed tree line and alpine areas, some very soft slab have formed on a variety of aspects. A buried a surface hoar layer from Jan 6 is lurking.

Avalanche Summary

Thursday's explosive control on low elevation targets released several size 2 slabs and loose snow avalanches. Natural activity was limited. Wind needs to firm up the snow into a slab. Fridays patrol was excellent visibility. Only a few size 2 soft slabs were noted from steep terrain. Sluffs up to size 2 out of extreme terrain were more prevelant.

Confidence

Due to the number and quality of field observations

Problems

Storm Slabs

30-50 cm thick soft slabs have formed where winds have touched the slope. This may overlie a buried surface hoar from Jan 6 in sheltered locations. Winds are forecasted to be moderate N on Saturday which may create slab conditions.

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

Winds have left the 30cm of storm snow from Wednesday relatively untouched "so far". It remains low density which causes sluffing and picking up significant mass in some cases to be a concern especially if terrain traps are involved.

Be cautious of sluffing in steep terrain.On steep slopes, pull over periodically or cut into a new line to manage sluffing.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 12th, 2013 4:00PM