Avalanche Forecast

Issued: Jan 11th, 2022 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 rbuhler, Avalanche Canada

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Ongoing southwesterly winds continue to redistribute the recent storm snow and touchy wind slabs are expected on Wednesday. Be alert to conditions that change with elevation and use extra caution in wind exposed terrain.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

Unsettled conditions are expected for Wednesday and Thursday with periods of flurries and periods of sunny breaks both expected. 

Tuesday Overnight: Mainly cloudy with a chance of isolated flurries, moderate SW wind, treeline temperature around -6 °C.

Wednesday: Mainly cloudy with sunny breaks and periods of flurries, moderate SW wind, treeline high around -4 °C.

Thursday: Mainly cloudy with sunny breaks and a chance of flurries, moderate to strong S wind, treeline high around -6 °C.

Friday: Periods of light snowfall, moderate S wind, treeline high around -6 °C.

Avalanche Summary

On Tuesday, the Avalanche Canada field team was able to ski cut reactive wind slabs on steep north aspects at upper treeline. With ongoing moderate SW wind continuing to redistribute the surface snow, wind slabs are expected to remain touchy on Wednesday. 

Snowpack Summary

20-40 cm of recent storm snow has been redistributed by strong southerly winds into fresh wind slabs in exposed terrain. These new wind slabs overlie a heavily wind-affected and faceted snow surface. The new snow will likely bond poorly to the old snow surfaces and newly formed wind slabs may remain reactive to human triggering for longer than normal. Reports from the Avalanche Canada field team include scouring to ground in exposed terrain, particular on north through east aspects from last week's outflow wind event. The height of snow is reported to be extremely variable. Older wind slabs from the outflow wind event last week are expected to have stabilized in most places but uncertainty still exists due to a limited number of recent observations. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Sheltered slopes at lower elevations will offer the safest conditions.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong southerly winds with relatively mild temperatures have redistributed the recent storm snow into reactive wind slabs in exposed terrain. These slabs likely overlie a weak interface and may remain reactive longer than normal. 

Older hard slabs had existed on all aspects from last week's northerly outflow winds. While these slabs have likely now stabilized in most areas, they could still be reactive in isolated places such as steep, unsupported slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 12th, 2022 4:00PM