Avalanche Forecast

Issued: Jan 6th, 2013 4:00PM

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

garth lemke, Parks Canada

Jasper.

Surface hoar has just been buried. Assess for possible windloading over this weakness the next few days. Loose sluffs appear to be picking up enough mass to be a concern for ice climbers. Quality skiing is limited to sheltered treeline locations.

Summary

Weather Forecast

Sunday overnight will bring light flurries. Monday may have a weak warm front followed by a cold front in the evening with limited amounts of snow. Expect gusty overnight winds. Tuesday is an unsettled and cool airmass with gusty alpine winds. Tuesday night into Wednesday may bring a more organized system but still too far away to have confidence.

Snowpack Summary

7mm surface hoar formed over New-years. It is now buried by 5cm of new snow. We call this the 'Jan 6th layer' which will need to be assessed as snowload increases. The mid-pack remains supportive where the snow depth is more than a meter otherwise facetting continues where shallow. Wind slabs are present in lee features at treeline and above.

Avalanche Summary

Avalanche patrols were conducted on the Maligne Road and the Icefields Parkway Saturday. Visibility was excellent and no new avalanches were observed other than a few loose size 1.5-2 out of very steep rocks where snowpack is shallow facetting it to point of no internal cohesion. Trigger likely was solar influenced but not for all.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

Wind slabs can be found above tree line in exposed terrain. These slabs have been unreactive to skier traffic; however, it remains possible to trigger one in steep unsupported terrain. Assess your transitions for changing conditions.

Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Loose Dry

Loose snow avalanches are possible in steep thin snowpack slopes and gully features as facetting process dominates. Solar triggering is most likely initiator but not solely responsible. They may knock you off a climb or bury you in a terrain trap.

Avoid travelling under cliffs that are exposed to sluffing from above.The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 7th, 2013 4:00PM