Avalanche Forecast

Issued: Feb 17th, 2016 4:46PM

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

Grant Statham, Parks Canada

Banff Yoho Kootenay.

We continue to expect human triggering to be likely in many areas, so watch for slopes that have not yet avalanched yet this winter as they may be primed to go and just waiting for a trigger.

Summary

Weather Forecast

A SW flow over the area will keep temperatures relatively warm over the next 24 hours. Expect up to 5 cm in flurries tonight and Thursday, along with temperatures from 0 to -9 and light winds from the south. Not bluebird, but a nice few days with a few cms of snow every day through the week.

Snowpack Summary

Fresh windslabs and cornice growth in the alpine with 15 to 30 cm of recent snow and west winds. A 50-100 cm slab overlies the January 6th weak layer of surface hoar, facets and sun crust and snowpack tests indicate an unstable bond between the two. The lower snowpack is facetted and quite weak in thinner areas (<1.5m) and settled in thicker areas.

Avalanche Summary

Avalanche activity has slowed down slightly, but we are just coming out of a natural cycle and have had many close calls in the last week indicating that human triggering remains likely in many areas. Today we observed a fresh size 2 avalanche on the slopes of Mt Jimmy Junior (Bow Summit area), SE aspect at 2300m.

Confidence

Problems

Persistent Slabs

50-100 cms of snow overlies the Jan 6th layer of surface hoar, facets and sun crust. Numerous reports of avalanches triggered on this layer over the last 5 days show that it is active. In thinner areas, isolated avalanches have scrubbed to ground.

Avoid paths that have not avalanched recently.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Be mindful of cross loaded features and the lees of ridges where moderate to strong W winds have recently formed windslabs 10-40 cm thick. If triggered, there is potential to step down to the persistent weak layer and to ground in thin areas.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Feb 18th, 2016 4:00PM