Avalanche Forecast

Issued: Jan 21st, 2023 4:00PM

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

Avalanche Canada jpercival, Avalanche Canada

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Expect wind slabs to be found on all aspects in both the alpine and at treeline.

Carefully assess for wind slabs in steep terrain below ridges.

Summary

Confidence

Moderate

Avalanche Summary

On Friday, operational ski cutting near Comox produced numerous small (size 1) dry loose avalanches on north aspect treeline terrain. During afternoon operations several small (size 1) wet loose avalanches on steep south aspect below tree line terrain were as well initiated via ski cutting.

On Thursday, Numerous avalanches on the north island in both the alpine and at treeline were observed with a few large (size 2), with most being small (size 1). One large (size 2) natural storm slab avalanche occurrence was observed and reported. Located on north aspect terrain between 1300 and 1400 m elevation, this avalanche was estimated at 15 cm deep and 60 meters wide, running 30 meters in length.

It also remains possible that riders could trigger storm slabs in sheltered areas, particularly if all the recent storm snow has a poor bond to the underlying melt-freeze crust.

Snowpack Summary

The upper snowpack consists of 30 to 60 cm of storm snow that has had some time to slowly settle. This overlies a pronounced melt-freeze crust that can be found at elevations 1500 m and below. Above 1500 m the melt-freeze crust begins to lose strength and is less than 1 cm thick.

The mid and lower snowpack remains moist and is generally well-settled and dense.

Snowpack depths are highly variable and have been recorded between 200 and 300 cm, the consistent theme is that they taper quickly with elevation. Although the snowpack in most forested areas below treeline remains below threshold depths. Expect at these elevations terrain that lacks tree coverage such as steep cliffs, and open alpine-like features to have the potential to produce avalanches.

Weather Summary

Saturday Night

Cloudy with very light snowfall, trace amounts of accumulation, Northwestern winds 30 km/h gusting to 80 km/h, treeline temperature -7 °C. freezing level 200 m.

Sunday

A mix of sun and cloud, no precipitation is forecast, Northwestern winds 80 km/h easing to 40 km/h, treeline temperature -1 °C. freezing level rising to 900 m.

Monday

Cloudy with light snowfall, accumulation 2 to 4 cm, Northwestern winds 50 km/h to 80 km/h, treeline temperature -2 °C. freezing level 800 m.

Tuesday

Cloudy with light snowfall, accumulation 2 to 4 cm, Northwestern winds 50 km/h to 80 km/h, treeline temperature -7 °C. freezing level 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Closely monitor how the new snow is bonding to the crust.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs have formed in lee terrain features from past wind and snow. Assess for wind slabs prior to committing to large terrain. Also use caution in steep wind-sheltered terrain, where the recent snow may take a bit of time to bond to an underlying crust.

Expect forecast northwesterly wind to transport available snow onto south-aspect terrain. Be cognizant of the potential for wind slabs to become present on all aspects in the alpine and at treeline.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Jan 22nd, 2023 4:00PM