Avalanche Forecast

Issued: Dec 17th, 2016 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Dry and Wind Slabs.

William Lawson, Parks Canada

Banff Yoho Kootenay.

Incoming snow and wind is expected to increase the avalanche hazard by the end of this weekend, watch for the timing of the approaching weather system.

Summary

Weather Forecast

Warmer temperatures and new snow are forecasted to arrive on Sunday night/ Monday morning. This approaching system is expected to arrive with moderate to strong with at higher elevations.

Snowpack Summary

The snowpack is heavily faceted with little structure in the upper 30cm, The Nov 12 crust is present except in thinner snowpack areas. Increase winds today have added to the variability in the alpine and developed isolated wind slab in lees. Incoming new snow and winds are expected to increase the hazard, with new load on a very weak snowpack.

Avalanche Summary

No significant slab avalanches have been reported or observed in the past week. Loose snow avalanches (up to size 1.5) are occurring out of steeper terrain. Because of a faceted snowpack avalanche tend to run further then you may expect.

Confidence

Problems

Loose Dry

The surface snow is facetted and weak, resulting in large sluffs in steep terrain. Sluffs are picking up mass and running fairly far. Pay attention to terrain traps where snow can accumulate into deeper deposits.

Be aware of party members below you that may be exposed to your sluffs.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Moderate to strong winds today have added to the wind slab in the alpine. The alpine snowpack is highly variable with wind affect ranging from impenetrable hard slab to loose faceted snow. Identifying this avalanche problem may be challenging.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

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