Avalanche Forecast

Issued: Apr 9th, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Fresh snow and shifting wind directions may form reactive wind slabs on many aspects. Pay close attention to the patterns of wind loading where you are riding and back off if you encounter whumpfing, cracking or hollow sounds.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Friday night - Mainly cloudy with isolated flurries / light to moderate northeast wind / alpine low temperature near -20 

Saturday - Mainly cloudy with isolated flurries / light to moderate northeast wind / alpine high temperature near -15 

Sunday - A mix of sun and cloud with isolated flurries / moderate southwest wind / alpine high temperature near -11 

Monday - Mainly cloudy / strong to extreme south wind / alpine high temperature near -9

Avalanche Summary

On Wednesday, we received report of a size 1 wind slab out of an unsupported lee feature observed from the highway.

Looking forward, reactive wind slabs may exist in lee terrain features on a variety of aspects due to a recent shift in wind direction.

Snowpack Summary

10-20 cm of new snow likely fell between Thursday night and Saturday morning. This adds to about 20 cm of recent, wind-affected snow. A change in wind direction may mean that wind slabs exist on many aspects.

The White Pass area has a deep snowpack without any layers of concern. The Tutshi Lake / Paddy Peak area should be assessed on a slope by slope basis, as some lingering snowpack weaknesses may still exist on isolated slopes. The Wheaton's shallower snowpack is dominated by hard wind slabs overlying sugary facets and depth hoar. It's an untrustworthy snowpack structure that requires conservative terrain selection and diligent travel habits. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent fresh snow and a shift in wind direction has likely formed wind slabs on many aspects.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 10th, 2021 4:00PM