Avalanche Forecast

Issued: Dec 28th, 2022 4:00PM

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

Avalanche Canada jpercival, Avalanche Canada

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Keep it simple ! The warm weather and continued precipitation is beginning to subside. Utilize simple terrain as you give the snowpack time to cool and heal.

Wind loaded features are the primary concern. Watch for wind slabs in sheltered terrain and expect reactivity to be greatest in areas they are sitting over surface hoar.

Summary

Confidence

Low

Avalanche Summary

On Tuesday explosive avalanche control and skier control produced several small (size 1.5) wind slabs. A noted small (size 1) loose wet avalanche occurred at lower elevation BTL.

On Monday explosive avalanche control produced several small (size 1.5) wind slabs

On Sunday 1 large avalanche (size 2) was triggered utilizing explosives on a east aspect at 1850 m. This avalanche ran on a surface composed of facets with a crown depth that was on average 40cm deep and ran for 200 meters.

If you are heading into the backcountry please consider filling out a Mountain Information Network report.

Snowpack Summary

A total of 26 mm of precipitation has fallen since Dec 25 . Snowfall totals of 16 cm of snow at elevations 1600 m and above. Below 1600 m there has been mixed precipitation and rain. Strong westerly winds continue to redistribute recent snow and is forming wind slabs at higher elevations. On south facing slopes wind slab could have formed over a sun crust. A layer of surface hoar down around 40cm can be found in sheltered terrain on all aspects up to 2000m. Reactivity will increase where wind slabs sit over this surface hoar, especially as temperatures increase on Tuesday.

A weak layer consisting of facets and a crust formed in November is now buried around 60cm deep.

In general, the snowpack is quite weak and faceted with average snowpack depths of around 150cm at treeline.

Weather Summary

Wednesday Night

Cloudy with light precipitation 1 to 2 mm. Light to moderate southwesterly winds 20 to 30 km/h. Freezing levels are expected to begin to descend to valley bottom. Alpine temps of -9°C.

Thursday

Mid day clearing and sun expected, very light snowfall, trace amounts. Moderate southwest winds 30 km/h. Freezing levels rising briefly mid day to 700 m with alpine highs of -6°C.

Friday

Overcast with light precipitation 1 to 3 cm. Light to moderate southwesterly wind 10 to 30 km/h. Freezing levels are expected to rise briefly mid day to 1000 m, with alpine highs of -2°C.

Saturday

Overcast with very light precipitation trace amounts. Moderate to Strong southwesterly wind 20 to 60 km/h. Freezing levels are expected to remain below 500 m, with alpine highs of -7°C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Keep your guard up at lower elevations. Wind slab formation has been extensive.
  • Be especially cautious as you transition into wind affected terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong to extreme westerly winds have likely stripped west facing slopes and deposited snow lower down on north and east facing slopes.

Watch for mid slope terrain features like rollovers. A reactive surface hoar layer can be found down 40cm in protected areas up to 2000 m in elevation.

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

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2

Valid until: Dec 29th, 2022 4:00PM