Avalanche Forecast

Issued: Feb 21st, 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.

a.l. horton, Parks Canada

Jasper.

Don't be fooled by the lack of recent natural avalanche activity. The stiffer upper snowpack is sitting on a weak and faceted base. Back-country travelers can trigger large avalanches from a distance and below avalanche paths.

Summary

Weather Forecast

Sun and cloud with light flurries the next few days. Temperatures are cooling slightly into the -12 to -16 range. Winds light from SW shifting Northerly on Wednesday. Light flurries through the week with minimal accumulation.

Snowpack Summary

25cm new snow and warm temperatures last week at the Columbia Icefields with 35km/hr SW winds built a windslab at TL and ALP. A rain crust exists below 1900m. The dense upper snowpack overlies a weak faceted lower pack making for unpredictable and dangerous avalanche conditions.

Avalanche Summary

On Friday several size 2-3 avalanches were remote triggered by skiers a significant distance away in the McCarib Pass area. Several avalanches to Sz 3 occurred Saturday along the Parkway with one dusting the highway from Mt. Wilson. Widespread whumphing and shooting cracks were noted in the Whistler creek area on all elevations.

Confidence

The weather pattern is stable on Wednesday

Problems

Deep Persistent Slabs

Widespread whumphing and shooting cracks in previously un-skied terrain. Recent natural activity and remote triggering of this weakness resulted in avalanches up to size 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

Likely

Expected Size

1 - 3

Wind Slabs

Previous 25cm snow 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 22nd, 2017 4:00PM