Avalanche Forecast

Issued: Feb 27th, 2022 4:00PM

The alpine rating is moderate, the treeline rating is low, 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 danger. The forecasted snow and wind for the White Pass area are enough to create a new wind slab avalanche problem.  

Summary

Confidence

Moderate - The snowpack structure is generally well understood. Uncertainty is due to the limited number of field observations. Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

Sunday Night: Mostly cloudy. 5-10 cm of snow expected in White Pass, less as you move northeast. Moderate southeast ridgetop wind. Alpine temperature around -5 °C.

Monday: Mostly cloudy. 0-5 cm of snow expected overnight with the highest amounts being right in White Pass. Moderate southeast ridgetop winds. Alpine high around -5 °C.

Tuesday: Partly cloudy. Possible trace of snow expected. Light east winds. Alpine high around -7 °C.

Wednesday: Partly cloudy. Possible trace of snow expected. Light to moderate southwest ridgetop winds. Alpine high around -8°C.

Avalanche Summary

We have received no reports of recent avalanche activity.

Snowpack Summary

A total of 10-15 cm of new snow is forecasted to fall in the White Pass area overnight Sunday, and through the day on Monday, with moderate Southeast ridgetop winds. This will likely form rider triggerable windslabs in leeward features in wind exposed terrain. The new snow overlies firm, wind effected surfaces in exposed areas on all aspects, and some soft snow in very sheltered terrain. 

A shallowly buried crust (around 20 cm deep) extends up to at least 1200 m on all aspects. It appears to be well bonded to surrounding snow, and is beginning to break down. Below this, the mid-pack is generally well-settled and strong in most areas. The basal snowpack consists of weak, sugary facets.

Terrain and Travel

  • Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.

Problems

Wind Slabs

An icon showing Wind Slabs

Up to 15 cm of new snow and moderate southeast winds are likely forming rider triggerable windslabs in leeward features in wind exposed terrain. These windslabs may not bond well to old, firm, wind effected surfaces, and even small avalanches may run farther than expected.

Whumpfing, cracking, and hollow sounds are all signs of instability that should cause you to back off into lower angle or less wind-loaded terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 28th, 2022 4:00PM