Avalanche Forecast

Issued: Jan 18th, 2013 4:34PM

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

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

Summary

Weather Forecast

Benign weather forecasted for the weekend. Thankfully the winds will ease off to light to moderate WNW, may see a trace of snow tomorrow, and otherwise expect partly cloudy to sunny skies for the weekend with alpine temperatures in the -6 range.

Snowpack Summary

30cm of snow sits over the Jan 6th interface (surface hoar in kootenay it's worth to dig down to check on the interface in a few places). Few avalanches have occurred on this interface, it may need more load. There is a strong midpack West of the divide. East side has been wind hammered leaving wind crust/slab over weaker snow layers.

Avalanche Summary

No natural activity was observed on a field trip into the backcountry of Yoho NP. Winds were howling once again at ridge-top from Lake Louise and east, but poor visibility prevented decent observations of high alpine start-zones. Widespread wind-effect was noted above tree-line. It may be hard to find good skiing in the alpine until the next storm.

Confidence

Problems

Wind Slabs

The warm temperatures and continued settling seems to be helping the recent wind slabs bond to the various underlying surfaces. These slabs have become stubborn to trigger, but human triggering is still possible.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Jan 6 layer could be a failure plane in areas with enough load or on the right slope (steeper unsupported features). May still need a little more load for this layer to become more reactive. Dig down & check for surface hoar (kootenay, sunshine).

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 19th, 2013 4:00PM