Avalanche Forecast

Issued: Feb 14th, 2015 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=19299&oPark=100092Tricky conditions continue. Cooler temperatures are on the the way, but it will take time for the snowpack to become less reactive. Solar input Sunday will augment the snowpack problems. SH

Summary

Weather Forecast

We are looking at a cooling trend (finally!) starting Sunday. Temperatures will go below -10C in the alpine and -6C at valley bottom. A mix of sun and cloud with light gusting moderate N-NW winds. Seasonal temperatures will persist for the next few days.

Snowpack Summary

10-20cm new snow up Hwy. 93N with drizzle and rain in other regions Saturday morning. 60-70cm of well settled snow from recent balmy temperatures sits over weaker facets and depth hoar in the bottom portions of the snowpack. A snow pit done at 2350m on Cirque peak demonstrates the snowpack layering common throughout the forecast region.

Avalanche Summary

Lots of natural activity to size 3.5 with wide propagations (hundreds of meters) stepping to ground. Most of these were triggered by fresh wind loading by N winds accompanied by solar effect. Over the last 2 days there have been notable skier triggered avalanches which stepped down to the basal weak layers. See here for photos of today's events.

Confidence

Due to the number of field observations on Saturday

Problems

Deep Persistent Slabs

The base of the snowpack remains weak due to basal depth hoar/facets. Avalanches have been seen to either fail on this layer, or start as a wind slab which steps down to the ground.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

Winds from many different directions have formed fresh wind slabs. These are primed for human triggering.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Wet

Ice climbers should be aware of loose wet avalanches out of steep terrain on solar aspects. The snowpack is saturated below 2000m currently and wont take much sun to break down any overnight freeze.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 15th, 2015 4:00PM