Avalanche Forecast

Issued: Feb 4th, 2016 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

We are in a holding pattern until more snow and wind arrive Saturday. This means natural avalanches aren't occurring on a regular basis, but we still lack confidence in the current snowpack to step out into bigger terrain. SH

Summary

Weather Forecast

Only a couple cm of snow Friday with increasing Westerly winds and alpine temperatures rising slightly but staying in the -6 to -10C range. Another 5-10cm forecast for Saturday and strong alpine winds.

Snowpack Summary

Wind slabs in alpine and tree line areas are now stubborn to trigger. The Jan 6 surface hoar/facet/sun crust layer, down 30-60cm, has becoming less reactive to skier triggering, however sudden collapse results persist on both the Jan 6 and Dec 3 layers. Isolated whumphing on mid-pack facets/surface have been observed this past week.

Avalanche Summary

No new avalanches were reported over the last 24 hours.

Confidence

Forecast snowfall amounts are uncertain on Saturday

Problems

Wind Slabs

Previous wind has built soft slabs 30 to 50cm deep in alpine and tree line lee areas. Although these slabs are slowly becoming more difficult to trigger, human triggering is still possible.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Avoid steep lee and cross-loaded features

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An average of 30-60 cm overlies the Jan 6 layer of surface hoar, facets and sun crust. Test results on this layer show it has become stubborn to trigger, but the potential for wide propagation remains.

Use careful route-finding and stick to moderate slope angles with low consequencesAvoid open slopes and convex rolls where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Feb 5th, 2016 4:00PM