Avalanche Forecast
Issued: Mar 13th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
wlewis,
Avalanche Canada
New and old wind slabs may be reactive to human triggers in exposed terrain.
Take care around ridgelines and mid slope terrain features like cross-loaded gullies.
Summary
Confidence
Weather Forecast
SUNDAY NIGHT: Light snow brings 5-10 cm overnight. Strong southwest winds. Freezing levels around 1000 m.
MONDAY: Another 5-10 cm over the day. Cloudy with moderate southwest winds. Freezing levels around 1200 m. Alpine high of -1.
TUESDAY: Up to 10 cm of snow possible overnight. Scattered flurries continue with moderate southwest winds. A mix of sun and cloud. Freezing level around 1000 m, alpine high of -2.
WEDNESDAY: Isolated flurries with moderate southwest winds. Partly cloudy. Freezing levels around 1000 m. Alpine high -2.
Avalanche Summary
Wind slabs were reactive to natural triggers on Saturday in immediate lee features (loaded by the southwest winds) to size 1.5.
A MIN report describes a size 2 slab avalanche triggered by a snowmobile on a southeast facing alpine slope. This avalanche may have involved deeper layers as it was estimated at around 80 cm deep. Solar input may have been a factor on this slope - even brief periods of sunshine in spring can have a significant effect on stability. Other reports noted small avalanches on steep, sun affected slopes.
Snowpack Summary
By Monday morning up to 10 cm of new storm snow is expected to bury the settling snow received over the weekend. Strong southwest winds will likely create wind loaded pockets on east facing terrain features.
The combined recent snowfall sits over a crust on south facing terrain features, which has been reactive in recent snowpack tests. A spotty surface hoar layer may be present at this interface as well, in isolated and wind sheltered features at treeline elevations.
Several other crust and surface hoar layers exist in the upper snowpack. These layers showed limited reactivity during the last storm. The thick mid-February crust is now buried 50-70 cm deep. These layers are unlikely to be human triggered, but possible to trigger with very large loads such as avalanches in motion or cornice falls.
The lower snowpack is well protected by the mid-February crust, and triggering avalanches below this layer is unlikely at this time.
Terrain and Travel
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Wind slabs are most reactive during their formation.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Wind Slabs
Expect most wind loading to be found on east facing slopes (lee to west/southwest winds).
Sensitivity to human triggers will be greatest on south facing slopes where storm snow overlies a crust.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 14th, 2022 4:00PM
