Avalanche Forecast

Issued: Feb 3rd, 2018 3:34PM

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

Alberta Parks matt.mueller, Alberta Parks

More snow will increase the hazard at treeline. Tread lightly and stick to low angle terrain with no overhead hazard.

Summary

Confidence

High -

Weather Forecast

Once again forecasts are conflicting. The forecast that nailed it today says we're due for another 10cm overnight with flurries tapering by morning. Then another pulse will arrive to bring another 10cm by late day tomorrow. The wind pattern suggest strong winds above 2800m, and light winds at treeline elevations. Temps will climb tomorrow to the -10 range.

Avalanche Summary

Loose dry avalanches were very easy to trigger today. They were up to sz1, but the size of the terrain is the deciding factor for snow volume. They could be much bigger in large terrain. Alpine observations were limited. Given the amount of snow, its almost certain there was a natural cycle ongoing.

Snowpack Summary

At the moment, there is 40 of new snow from the past couple of days. So far this storm has brought 20cm of cold, low density snow at treeline elevations. Alpine elevations had some wind affect today, but treeline was surprisingly calm. A profile at the top of Tryst Chutes had the Dec 15th down 115cm, Jan 6th down105cm & the Jan 18th down 90cm. The test results were mixed. We had one test fail with sudden results from a moderate load (CTM12 SP). This was notable and concerning as if failed on the dec 15th layer. The other test had slightly better results, but still concerning. In this test, it failed with a heavier load (ECTP22 on the Jan 6th). The take home point: there is still huge uncertainty within the snowpack. A failure on any of those layers will be a big avalanche.

Problems

Loose Dry

An icon showing Loose Dry
Ice climbers, don't climb in gully features right now! Skiers, expect sluffing in steep terrain. These avalanches could also act as a trigger for deeper layers. This is why it is the first problem.
Avoid areas with overhead hazard.Sluffs may trigger deeper instabilities.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely - Certain

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs
Wind slabs are extensive in the alpine down to tree line. These may also step to deeper layers.
Avoid steep lee and cross-loaded slopesAvoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Persistent Slabs

An icon showing Persistent Slabs
These are deeply buried and making us more and more nervous. Be sure to assess them thoroughly.
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Avoid convex rolls at and below treeline where buried surface hoar may be preserved.Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Feb 4th, 2018 2:00PM

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