Avalanche Forecast

Issued: Jan 13th, 2022 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Choose terrain sheltered from the wind to find the best riding and the lowest avalanche hazard. Moderate snowfall should refresh the riding, but back off if you see shooting cracks or other signs of instability.

Summary

Confidence

Low - Uncertainty is due to how the snowpack will react to the forecast weather. Uncertainty is due to the limited number of field observations.

Weather Forecast

Thursday Night: Mostly cloudy. 5-10 cm of snow expected. Strong to extreme south wind. Treeline high around -4 °C.

Friday: Mostly cloudy. 0-5 cm of snow expected. Moderate to strong south wind in the morning, becoming southest by the afternoon. Freezing level rising to around 500 m.

Saturday: Partly cloudy. Possible trace of snow expected. Light west wind becoming moderate southwest in the afternoon. Treeline high around -7 °C. 

Sunday: Mostly cloudy. 0-5 cm of snow expected. Moderate south wind trending to southwest at higher elevations. Treeline high around -7 °C. 

Avalanche Summary

With new snow and ongoing moderate to strong south through southwests wind and mild temperatures, wind slabs are expected to remain reactive to human triggering on Friday.

On Tuesday, the Avalanche Canada field team was able to ski cut reactive wind slabs on steep north aspects at upper treeline. Their MIN report has a great photo of a skier triggered avalanche on a small test slope. 

Snowpack Summary

Up to 20 cm of new snow is forecasted to fall overnight Thursday and through the day on Friday. Strong south winds will accompany this snow, continuing to build reactive slabs in lee features. This new snow overlies 30-50cm of rapidly settling storm snow that fell on very firm surfaces in White Pass.

In open, wind exposed terrain at treeline, a spotty rime crust was reported on Wednesday. Riding quality has been improving since the extreme wind event but thinly buried hazards still exist in exposed areas. These hazards include rocks and waves of sastrugi. 

Check out here and here for the two most recent Mountain Information Network (MIN) posts from the field team for more details on recent the snow conditions. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Sheltered low elevation terrain will likely offer the best and safest riding today.

Problems

Wind Slabs

An icon showing Wind Slabs

New snow and ongoing moderate to strong southerly winds continue to form reactive wind slabs in exposed terrain. These slabs may overlie a weak interface and could remain reactive longer than normal. 

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Jan 14th, 2022 4:00PM