Avalanche Forecast

Issued: Jan 31st, 2016 4:00PM

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

Max Darrah, Parks Canada

Jasper.

Recent storm snow and strong winds have created fresh windslabs in exposed areas, particularly at treeline and above. Field teams measured some of these slabs at 90cm thick and displaying touchy results in snow profiles and stability tests.

Summary

Weather Forecast

Cool temperatures, with freezing levels remaining below 1100m for next 3 days. Light Southwest wind, gusting to moderate. Light scattered flurries amounting to less than 5cm.

Snowpack Summary

Up to 30 cm fell in the Icefields area on Thursday with moderate SW winds building touchy soft slabs on lee slopes at tree line and above. It rained at lower elevations making for a potential rain crust surface. This new snow rests on either a decomposed surface hoar layer that has formed the last few weeks or a facetted unconsolidated snowpack.

Avalanche Summary

Saturday natural activity noted up to size 3 running relatively far on a variety of aspects mainly in alpine. Explosive work was mixed results with sluff's to soft slabs up to size 2.5 on the range of aspects and elevations. On Friday, a skier accidental at Parkers Ridge, size 3, 1 involvement, no injuries. Depth 10-240cm x 400m x 400m.

Confidence

Due to the number of field observations

Problems

Persistent Slabs

30 cm of storm snow from Thursday continues to build into a slab overlying a weak facetted snowpack or decomposed surface hoar layer.

Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

Triggering is likely in steep terrain. Thursdays' new snow added to this problem in many locations.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Feb 1st, 2016 4:00PM