Avalanche Forecast

Issued: Feb 19th, 2017 4:00PM

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

mark herbison, Parks Canada

Jasper.

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=26206&oPark=100092Special Public Avalanche Warning has been issued for Jasper National Park due to dangerous avalanche conditions.

Summary

Weather Forecast

Light flurries over the next few days will accumulate up to 10cm of new snow. Temps to remain between -3 to -10 in the Alpine with light (1-25km/hr) SW winds. Freezing levels could go as high as 1700m on Monday.

Snowpack Summary

25cm HST in the past 5 days along the Columbia Icefields, previous 35km/hr SW winds have built, yet another, layer of windslab TL and ALP. A rain crust (up to 20cm) exists below 1900m. The denser upper snowpack overlies a weak faceted lower pack, making for very tricky and dangerous avalanche conditions.

Avalanche Summary

Several avalanches up to Sz 3 occurred yesterday along the Parkway, one of which dusted the highway from Mt. Wilson. Several avalanches reported today in the backcountry terrain adjacent to the Marmot Ski area.Widespread whumphing and shooting cracks were noted on all elevations.

Confidence

Due to the number of field observations on Saturday

Problems

Deep Persistent Slabs

Widespread whumphing and shooting cracks in previously un-skied terrain. Recent natural activity up to Sz 3 failing on the weak faceted snowpack.

Be aware of thin areas that may propogate to deeper instabilites.Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

25cm HST and moderate SW winds have added to the windslab problem in the alpine and open tree-line features.

Use caution in lee areas. Recent wind loading have created wind slabs.Be aware of the potential for wide propagations due to the presence of hard windslabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Feb 20th, 2017 4:00PM