Avalanche Forecast

Issued: Jan 29th, 2017 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Ice climbers should be very cautious in steep gullies. Strong/extreme winds have loaded start zones and have formed touchy wind-labs.

Summary

Weather Forecast

Continued strong to extreme wind is expected near 3000m until Monday morning. Up to 15cm of new snow is also expected. Beyond Monday we expect to see a cooling trend accompanied by clear weather.

Snowpack Summary

Small amounts of new snow continues to be transported into lee areas by strong to extreme wind - particularly near Lake Louise and on the E side of Hwy 93N. Near the divide, deeper snow-packs are stronger and more supportive. Surface hoar up to 10mm was buried by a trace in some areas and blown away in others by strong W winds Saturday and Sunday.

Avalanche Summary

Although reported from the Jasper forecast region a very close call was observed yesterday on the ice climb 'Polar Circus'. Two ice climbers narrowly missed being hit by a large avalanche that went right over their heads. It was suspected to be size 2.5. The high winds in the area likely was the cause for the slide.

Confidence

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

Problems

Deep Persistent Slabs

The snowpack is weak. Slopes where a slab sits over the deeper weak layers should be treated as suspect. Avoid steep slopes with this structure. Continued conservative choices will remain important for some time.

Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Continued strong to extreme wind and light amounts of new snow continue to form slabs in lees areas. These will remain reactive in the short term while winds speeds stay elevated.

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Jan 30th, 2017 4:00PM