Avalanche Forecast
Issued: Dec 25th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
jpercival,
Avalanche Canada
Expect winds slabs to become touchy to triggering on Monday as rain and warm temperatures rapidly settle the upper snowpack.
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
Avalanche Summary
On Friday, wind slabs were reported to size one from natural and human triggers.
If you are heading into the backcountry please consider filling out a Mountain Information Network report.
Snowpack Summary
Strong westerly winds have redistributed recent snow into 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 30cm 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 Monday and 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
Sunday Night
Mostly cloudy with light flurries bringing trace amounts of new snow. Moderate westerly winds. Freezing levels around 500 m, high temperatures of -3°C.
Monday
Cloudy with trace amounts of snow expected, or light rain. Strong southwest winds return. Freezing levels rise to 2000 m. High temperatures of +3 °C.
Tuesday
Wet snow and rain continues with another 5 to 10 mm. Strong westerly winds with the freezing levels remaining elevated at 2000 m.
Wednesday
Light precipitation 1 to 5 mm. Freezing levels are expected to begin to descend to around 500 m.
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
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. In sheltered terrain slabs may sit over a layer of reactive surface hoar.
Aspects: North, North East, East, South East, South.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 26th, 2022 4:00PM
