Avalanche Forecast

Issued: Jan 5th, 2015 8:11AM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs, Persistent Slabs and Loose Dry.

ali haeri, Parks Canada

Glacier.

We've had lots of new snow and the winds are just starting to ramp up. We had a close call yesterday with a rider triggered avalanche. Reactive surface hoar as well as storm snow instabilities should be enough to stick to conservative terrain.

Summary

Weather Forecast

Continued north west flow over the Interior bringing cloud, light snow today and cool temperatures. Slight break between storms for most of today until this evening when the next wave will arrive. Moderate to heavy snow is forecast with stronger winds, from north and south depending on elevation into Tuesday night. High pressure ridge for Wednesday

Snowpack Summary

Recent storm snow amounting to over 50cm over wind slabs in exposed areas. The Dec 17th surface hoar layer is down 70-100cm sitting on top of a thick rain crust facet combo below 2100m and over a settled snow above. This widespread layer has been most reactive at tree line. Well settled mid-pack over top the basal Nov 9 crust.

Avalanche Summary

Yesterday, a size 2.0 skier accidental avalanche in Teddy Bear trees. East aspect, ~2000m, ~35 degrees, ~65cm deep, 40-50m wide, ~150m long. Avalanche was triggered near the ridge crest and rider went for a ride through the trees. Slabs pulled out lower down as well. Several large natural avalanches within the highway corridor early this morning.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

50cm of recent storm snow with more in the forecast. Settlement and winds have formed soft slabs particularly at ridge crests. Winds are on the rise and expect conditions to become more sensitive as winds continue.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

The Dec17 surface hoar is most reactive at treeline. As snow load continues the consequences of an avalanche on this layer increase, careful decision making is still necessary. We suspect yesterdays Teddy Bear Trees avalanche to be on this layer.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Dry

50 cm of storm snow is likely to move fast in sufficiently steep terrain. Be aware of your sluff as it could pick up mass and turn into an avalanche.

Avoid travelling on ledges and cliffs where sluffing may have severe consequences.Be aware of party members below you that may be exposed to your sluffs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 6th, 2015 8:00AM