Avalanche Forecast

Issued: Dec 4th, 2022 4:00PM

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

Avalanche Canada jleblanc, Avalanche Canada

Mixed snow conditions can be found.

Evaluate slopes on an individual basis before committing to them.

 

Summary

Confidence

Moderate

Avalanche Summary

A skier accidentally triggered a wind slab on a steep alpine feature near Flute Bowl on Saturday. Several small loose wet avalanches (size 1) were reported on steep alpine south-facing slopes over the weekend.

Keep sharing your observations via the MIN; it helps strengthen our information gathering!

Snowpack Summary

On shaded terrain at all elevations, surface hoar (up to 10 mm) is present, along with unconsolidated snow. On steep south-facing slopes, a sun crust has developed this weekend. The upper snowpack consists of 20-50 cm of light snow, overlying old surfaces such as wind-affected surfaces.

Down 40-60 cm in the snowpack, a thick melt-freeze crust is found up to 2200 meters. Faceting has been observed between the wind slab and the crust. Professionals are concerned about the possibility of wind slabs fracturing at this deeper interface.

The snowpack sits around 70 to 120 cm at the treeline and up to 180 cm in the alpine. Much of the below treeline elevation band is below the threshold for avalanches.

Weather Summary

An arctic ridge of high pressure will continue to be the main attraction. Conditions will be sunny and dry along with a northerly flow pattern. The next frontal system is expected on Wednesday afternoon.

Sunday Night

Clear sky. No precipitation. Light northerly ridge wind. Low of -5 C at treeline. Freezing level lowering to 1000 m. Temperature inversion.

Monday

Mostly sunny. No precipitation. Light northwesterly ridge wind. High -6 C. Freezing level around at valley bottom. Possible temperature inversion.

Tuesday

Cloudy. Isolated flurries. Westerly ridge wind up to 50 km/h. High -8 C. Freezing level around at valley bottom.

Wednesday

Partially cloudy. 5 cm in the afternoon. Southwesterly ridge winds up to 40 km/h. High -8 C. Freezing level around at valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
  • Carefully evaluate steep lines for wind slabs.

Problems

Wind Slabs

An icon showing Wind Slabs

Newer wind slabs have formed in cross-loaded terrain due to reverse loading during the weekend. Lingering old wind slabs exist in lee features. Keep approaching convex and unsupported features with caution.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 5th, 2022 4:00PM