Avalanche Forecast

Issued: Jan 22nd, 2017 6:09PM

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

tim haggarty, Parks Canada

Banff Yoho Kootenay.

While avalanche activity following the recent storm may be diminishing to warrant lower danger ratings: Keep your guard up! This snowpack does not inspire confidence and warrants careful decision making and route selection.

Summary

Weather Forecast

A bit more cloud with a chance of trace amounts of precip for Monday before skies clear. Cold nights will be the price to pay for sunny afternoons with maybe some light winds reaching -5 C at valley bottom elevations. Watch for the sun to create moist snow on steep SW slopes given these conditions.

Snowpack Summary

The snowpack is quite localized. 10-40 cm of storm snow (often windslab) rests on weak facets. Deeper layers of weak facets and depth hoar are common. A supportive midpack can be found, but it is often friable and may contribute to deeper failures. Lower elevations have unsupportive bottomless facets!

Avalanche Summary

No new avalanches were reported today.

Confidence

Problems

Deep Persistent Slabs

The midpack in most areas is weak and facetted. Any slab sitting overtop of this weakness should be considered suspect and there is a high level of uncertainty and variability concerning this layer.

Be aware of thin areas that may propogate to deeper instabilites.Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Recent winds ranging from East to SW have created some new windslabs in alpine and treeline features. In some cases, these have been observed to provide enough weight to step down to the deep persistent layer, causing a larger avalanche.

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, West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 23rd, 2017 4:00PM