Avalanche Forecast

Issued: Mar 9th, 2017 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 Deep Persistent Slabs.

garth lemke, Parks Canada

Jasper.

Choose simple terrain that is well supported. A buried unstable surface hoar layer was found at Parkers Ridge on a South aspect at treeline sitting on a crust.

Summary

Weather Forecast

Thursday night will be -20, flurries, and light E to SE winds. Friday - Sunday will be highs of -5 at the Icefields and flurries. Winds will increase Westerly 26km/hr on Friday then decrease to light Westerlies Saturday-Sunday.

Snowpack Summary

March 3rd's 45cm of storm snow has settled into a 30cm soft slab at treeline and above. It is testing as a resistant planar fracture characteristic. The lower snowpack is weak with depth hoar and a November rain crust. S aspect at Parker's there is a Surface hoar layer on a sun crust down 30cm testing unstable sudden planar fracture characteristic.

Avalanche Summary

Nothing new was noted with good visibility on Thursday's patrol town to Churchill slide path. No whumphing or cracking in the area but stayed near the trees. Skiers on March 7 in Bald hills triggered a size 2 from a km away. Report and pictures can be viewed on CAA's Mountain Information Network.

Confidence

Freezing levels are uncertain on Friday

Problems

Persistent Slabs

45cm of storm snow from March 3 has evolved into a soft slab and melded in many locations to the midpack below. South TL aspects the new snow was found resting on a decomposing surface hoar layer on a crust about 30cm down. It tested unstable.

Watch for whumpfing, hollow sounds, and shooting cracks.Be wary of slopes that did not previously avalanche.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Deep Persistent Slabs

March 3rd 45cm of new snow load produced size 3's. This activity has subsided. They were from the alpine and treeline elevations running to valley bottoms. One should consider it a concern if the persistent slab is initiated and steps down.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Avoid shallow snowpack areas where triggering is more likely.