Avalanche Forecast

Issued: Jan 22nd, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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A heavily wind-affected surface dominates the landscape.

Avoid wind-loaded terrain features and look for signs of instability such as whumpfing, shooting cracks, hollow sounds, and recent avalanches.

Summary

Confidence

Moderate - Uncertainty is due to the extreme variability of wind effect on the snowpack.

Weather Forecast

Saturday Overnight: Snowing, around 5 cm accumulation in White Pass. Moderate to strong southerly winds. Freezing level around 500m

Sunday: Continued snowfall, around 5 cm accumulation. Moderate to strong southerly winds. Freezing level around 500m.

Monday: Cloudy, light snowfall. Winds increasing, strong to extreme from the south. Freezing level near valley bottom. 

Tuesday: Snowing, up to 5 cm accumulation. Moderate to strong southwest winds. Freezing level around 500m. 

Avalanche Summary

When the sun came out on Friday, several natural loose wet avalanches up to size 1.5 were observed in thin snowpack areas inland from White Pass. These avalanches entrained most of the snowpack, pulling pockets of slab in the track. 

Snowpack Summary

In the past 2 days, a significant storm brought around 40 cm of new snow to the White Pass area. The accompanying strong to extreme southerly winds left a heavily wind-affected surface at all elevations comprised of deep deposits of hard wind slabs, sastrugi, and areas stripped back to the ground or old crusts. 

Below the new snow, a variety of old surfaces exists including a thin rime crust at treeline and hard old wind slabs at higher elevations. In the past week, warm temperatures have promoted settlement and bonding in a hard, consolidated mid-snowpack. The lower snowpack is weak and facetted above the ground surface.

Terrain and Travel

  • Keep your guard up at lower elevations. Wind slab formation has been extensive.
  • Avoid slopes that sound hollow or drum-like.
  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

In the White Pass area, up to 40 cm of new snow has been redistributed by strong southerly winds into wind slabs in lee areas at all elevations. Winds may subside a little today, but if there is any snow left to transport it will be creating fresh, more reactive slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Jan 23rd, 2022 4:00PM