Avalanche Forecast

Issued: Jan 21st, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Strong winds, warming temperatures, and new snow are a recipe for dangerous avalanche conditions. 

Virtually all slopes are heavily wind affected, making for unwelcoming riding conditions.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain. Uncertainty is due to the extreme variability of wind effect on the snowpack.

Weather Forecast

Friday Overnight: Snowing, 10-20 cm of accumulation in White Pass. Strong southwest winds. Freezing level around 600m.

Saturday: Continued snowfall, 5-10 cm of accumulation. Moderate to strong southwest winds. Freezing level 500-800m.

Sunday: Mainly cloudy, trace to 5 cm of new snow accumulation. Strong southerly winds. Freezing level 500m.

Monday: Partially cloudy, trace new snow. Moderate to strong southwest winds. Freezing level at the valley bottom.

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

A significant storm is impacting the region and has brought 15-30 cm of new snow to the White Pass area with continued snowfall throughout today. The accompanying strong to extreme southerly winds have created extensive wind effect at all elevations, building deep deposits of wind slab in lee areas and generally making for adverse travel conditions and poor snow quality. 

Below the new snow, the snowpack is heavily wind affected. A variety of old surfaces exists including a thin rime crust at treeline and hard old wind slabs at higher elevations. The lower snowpack is facetted above the ground surface.

Terrain and Travel

  • Keep your guard up at lower elevations. Wind slab formation has been extensive.
  • Avoid all avalanche terrain during periods of strong wind.
  • Avoid slopes that sound hollow or drum-like.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

An intense storm impacting the region has brought 15-30 cm of new snow to the White Pass, with continued snowfall expected throughout the day. The accompanying strong to extreme southerly winds and rising temperatures will continue to create deep deposits of wind slab in lee areas. 

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Loose Wet

An icon showing Loose Wet

This is mainly a concern for inland areas with a thin snowpack. If the sun comes out today, strong solar radiation compounded by warm temperatures may create wet loose avalanches on steep solar aspects. In shallow snowpack areas, wet loose avalanches have the potential to step down to the ground and entrain a large amount of mass.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Jan 22nd, 2022 4:00PM