Avalanche Forecast

Issued: Feb 13th, 2020 4:00PM

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

Avalanche Canada mmueller, Avalanche Canada

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The winds have blown around the recent snow and formed wind slabs almost everywhere. They range in density, but generally they get harder/more reactive near ridges. They will take a day or two to settle out. In the mean time, the skiing is still good in sheltered areas.

Summary

Confidence

High -

Weather Forecast

Overnight lows will settle around -12 by early morning. The day time high will hit -9 by mid afternoon. Flurries will bring trace amounts of snow. Treeline winds will be moderate, gusting to strong (44km/hr) from the west.

Avalanche Summary

We did see some wind induced activity today. Little Tent ridge had soft slabs fail on east aspects. They were sz1.5, started in the alpine and ran to mid track.

There was also a sz2.5 on Old Goat Mountain that started with a small cornice failure. The resulting windslab pulled a larger pocket to ground. It was a south aspect, on a high, unsupported alpine slope. 

Snowpack Summary

No new snow last night, but we sure got the winds! This morning they were strong and from variable directions at treeline and alpine. By mid afternoon they atleast settled to a SW flow, but still raged. There are new windslabs everywhere, either because of lee loading or crossloading. Steep, unsupported slopes were cracking today, but tough to get going in ski cuts. Other than that the midpack has no change with the bottom 30cm still rotten and weak depth hoar. HS at 2200m 150cm. Cornices have quickly developed and will likely shed as the winds continue.

Terrain and Travel

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Variable winds have made new slabs on all aspects. West aspects have a more crossloaded look, while the east have a traditional lee loading pattern.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The weak basal layers are still a concern. An avalanche that occurred in the past 24 hours was a slide that stepped down to the basal layers and involved the entire snowpack. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3.5

Cornices

An icon showing Cornices

These will likely trigger slabs below the ridges and possibly trigger the deeper layers. If this happens, expect a very large avalanche. 

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Feb 14th, 2020 4:00PM

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