Avalanche Forecast

Issued: Feb 6th, 2022 4:00PM

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

Avalanche Canada TRettie, Avalanche Canada

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Avoid avalanche terrain at treeline where triggering a persistent slab is most likely. This layer can be remotely triggered, think about overhead hazard.

Summary

Confidence

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Weather Forecast

Sunday night: light snow starting around midnight bringing trace amounts of snow. Strong southwest winds and a low of -1 at 1400m. 

Monday: stormy weather with 5 to 10cm of snow and moderate to strong west winds. Freezing levels around 1300m.

Tuesday: light flurries bringing trace amounts of snow. Strong west winds and freezing levels around 1300m.

Wednesday: sunny with no snow expected. Moderate northwest winds and freezing levels rising to 3000m.

Avalanche Summary

On Saturday in the South Coast Inland region a fatal size 3 skier triggered avalanche was reported in the Duffy Lake area. It ran on the persistent weak layer from late January. This avalanche was triggered in a upper treeline feature on a northeast aspect and showed significant propagation. Click here to read a more detailed report. This is the same layer that was responsible for a skier triggered size 2.5 avalanche last week on Rainbow mountain. Several smaller skier triggered avalanches on this layer were also reported throughout the week. Most of the avalanche activity on this layer has taken place between 1800m and 2000m but it can be found above and below this elevation band. 

On Friday and Saturday several skier triggered size one wind slab avalanches were reported. These avalanches were triggered in steep features just below ridge crests at treeline and above.

Snowpack Summary

New wind slabs could form throughout the day on Monday on Easterly slopes. As temperatures fall a new crust could form on all aspects below treeline and on south facing slopes in treeline and above.

10 to 20 cm of snow with moderate to strong southwest winds on Friday have formed wind slab on north and east aspects in the treeline and alpine.

A layer of facets on a crust is now buried down 30 to 70 cm. This layer is widespread between 1800 m and 2000 m, but could be found above and below this elevation band. It has produced several human and remote triggered avalanches in the past few days. In sheltered terrain at treeline and above surface hoar can also be found on this layer.

Terrain and Travel

  • Be aware of the potential for large avalanches due to the presence of buried weak layers.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Extra caution is needed around cornices under the current conditions.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.

Problems

Persistent Slabs

An icon showing Persistent Slabs

30 to 70 cm of snow sits over a facet-crust weak layer combination that is possible to human trigger. Recent observations demonstrate the potential for this problem to be triggered remotely and propagate far and wide. It is most reactive between 1800 and 2000m but can be found above and below this elevation band. Avoid avalanche terrain at this elevation and be aware of slopes above that could be remotely triggered.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs

Rider triggerable wind slabs could be found on north and east aspects in the treeline and above. Recent winds have also formed unstable cornices , avoid slopes with large over hanging cornices.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Feb 7th, 2022 4:00PM