Avalanche Forecast

Issued: Feb 25th, 2016 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Deep Persistent Slabs, Cornices and Loose Wet.

Grant Statham, Parks Canada

Banff Yoho Kootenay.

Friday is a day to be careful. Not HIGH by definition, but it could be a hot day and if so avalanches will run. The snowpack is poor - today we experienced a frightening whumph and crack on a steep north facing slope. Things have not improved much.

Summary

Weather Forecast

Blue skies, sunshine and warm temperatures forecast for Friday, with strong winds at higher elevations (possibly) keeping things a bit cool (but don't count on it). Freezing levels may reach 2000m - sheltered, sun exposed places will be like a convection oven on Friday.

Snowpack Summary

The snow surface is a mix of surface hoar, suncrust and wind effected snow that overlies a generally weak snowpack. Shallow areas are very weak and today we observed a large whumph and crack propagation on a 35 degree N facing slope in the alpine. There are two weak layers in the mid-pack (Jan 6 and Feb 11) which present additional instability.

Avalanche Summary

Some wet loose snow avalanches were observed today in sheltered alpine bowls. On Wednesday a large slab was triggered by a cornice up high on the Wapta. On Tuesday a small sluff ran over the French Reality Ice Climb in Kootenay and triggered a 100 cm deep slab on the slope below.

Confidence

Timing or intensity of solar radiation is uncertain on Friday

Problems

Deep Persistent Slabs

Generally the snowpack is poor throughout the BYK region. Facets, surface hoar and suncrust all exist at different levels in the snowpack and in different locations. Use caution on any large slopes that have not yet avalanched; good chance they will.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Cornices

Friday afternoon is expected to be hot, and this means cornices will weaken and potentially fall off. Don't travel under except early in the morning, and if you must then spread out and get it over with quickly.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Wet

Ice climbers! Get out of any steep gully features by noon, as we expect wet slush to be running down low and mid-elevation gullies by the afternoon. Start early!

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 26th, 2016 4:00PM