Avalanche Forecast

Issued: Dec 28th, 2021 4:00PM

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

Avalanche Canada TRettie, Avalanche Canada

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 Keep an eye on the extend of wind transport throughout the day. Shallow but touchy wind slabs will likely build as a result of increasing west winds on Wednesday. 

Summary

Confidence

Moderate -

Weather Forecast

Tuesday night: outflow winds will continue at valley bottom. Winds in the alpine will be moderate from the north east. No new snow is expected. There is a possibility of a temperature inversion with -13 at 1400m.

Wednesday: light snow throughout the day with up to 10cm expected. winds in the alpine will be moderate from the southwest. a temperature inversion could develop late in the afternoon with -7 at 1400m.

Thursday: no new snow expected and moderate north winds in the alpine. High of -16 at 900m.

Friday: snow beginning in the afternoon with light southwest winds in the alpine. Possible temperature inversion with -8 at 1400m.

Avalanche Summary

No new avalanches were reported in the region on Monday. We suspect new wind slab will develop throughout the day on wednesday.

Snowpack Summary

New snow and wind arriving Wednesday afternoon will form new wind slab in the treeline and alpine. This new snow might be enough to reload some scoured surfaces on east aspects.

Another surface hoar layer was buried recently , it is not a problem yet.

The December 18th surface hoar/facet layer is down 30cm, the surface hoar was observed up to 12mm in both the treeline and below . It is likely only a problem in isolated locations in the treeline where wind slab has formed above it.

The December 7 persistent weak layer is now typically down 100cm and has not produced avalanches in over a week.

Snowpack depths vary greatly across the region, expect to find anywhere from 100-300 cm of snow around treeline.

Terrain and Travel

  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
  • Wind slabs are most reactive during their formation.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slab could form throughout the day on Wednesday on north and east aspects. These new slabs will likely be touchy but limited in size. Old wind slab will likely still be found on south and west. Sensitivity to triggering will be greatest near ridge crests and in the treeline and below where wind slab has formed above the December 18th surface hoar layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 1.5

Valid until: Dec 29th, 2021 4:00PM