Avalanche Forecast

Issued: Dec 4th, 2016 4:00PM

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

grant statham, Parks Canada

Banff Yoho Kootenay.

Excellent riding conditions with 30 cm of light dry snow in the past 48-hours but strong NE winds today will have produced wind slabs to watch for. Bust out your big down jacket, as temperatures are about to plummet reaching -28 by Wednesday.

Summary

Weather Forecast

Snow flurries continuing into Monday, but the bulk of the precipitation from this storm has fallen already. On Monday the cold air truly arrives: the day starts at -13 and by evening we should reach -25. Looks like cold, calm and clear for the week ahead.

Snowpack Summary

30 cm of light, dry storm snow has fallen over the past 48-hours and instabilities within this storm snow are failing easily down 10 and 25 cm with snowpack tests. In exposed areas, wind slabs have been created over these weak layers by Sunday's NE winds. Deeper in the snowpack, the Nov crust appears to weakening, with easy test results observed.

Avalanche Summary

Sunshine Village patrol was reporting soft wind slabs formed with minimal propagation (fractures not spreading far), and otherwise no avalanches observed or reported - although visibility was poor.

Confidence

Problems

Wind Slabs

Hard to get a solid handle on this problem, but with 30 cm of new snow and a lot of NE wind today, wind slabs should be expected. Reverse loading creates challenges as things can be backwards, so make careful observations of how the snow is loaded.

Be careful with wind loaded pockets while approaching and climbing ice routes.Keep an eye out for reverse loading created by an upslope storm.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

30 cm of light, dry snow will be sluffing and creating much unpleasant spindrift for ice climbers.

Be very cautious with gully features.Use caution above cliffs where small avalanches may have severe consequences.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

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