Avalanche Forecast

Issued: Feb 15th, 2015 4:02PM

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.

Conrad Janzen, Parks Canada

Banff Yoho Kootenay.

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=19299&oPark=100092Tricky conditions continue at upper elevations despite cooler temperatures. Watch for solar heating when the sun comes out. Be patient and stick to moderate angled terrain with low consequences, it will take time for the snowpack to heal.

Summary

Weather Forecast

Light NW winds, tree line temperatures staying below freezing, no new precipitation, and a mix of sun and clouds is the forecast for the next few days. Watch for the effects of solar heating on steep south aspects when the sun comes out.

Snowpack Summary

Some wind effect in open areas above tree line. Temperature crust present below 1800m. 60-70cm of well settled snow from recent storms and warm temperatures sits over weak facets and depth hoar at the bottom of the snowpack. A snow pit done at 2350m near Cirque Peak on Saturday demonstrates the snowpack layering common in the forecast region.

Avalanche Summary

No new avalanches observed on Sunday. Lots of natural activity up to size 3.5 with wide propagations in the past 48 hrs. Most of these were triggered by wind loading accompanied by solar heating. There have also been notable skier triggered avalanches which stepped down to the basal weak layers. See here for photos of recent events.

Confidence

Problems

Deep Persistent Slabs

The base of the snowpack remains weak due to the presence of basal depth hoar and facets. Avalanches have been seen to either fail on this layer, or start out as a wind slab and then step down to this layer with wide propagations.

Be aware of thin areas that may propogate to deeper instabilites.Use careful route-finding and stick to moderate slope angles with low consequences

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

Winds from both the SW and NW have formed fresh wind slabs in open areas above tree line. These are slowly settling out but can still be triggered and may step down to the basal weak layers.

Use caution in lee areas. Recent wind loading have created wind slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 16th, 2015 4:00PM