Avalanche Forecast
Issued: Jan 9th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
zryan,
Avalanche Canada
Seek out sheltered terrain and use caution on steep, open slopes where buried weak layers may exist.
Days are short and temperatures are cold; read this blog on managing cold weather.
Summary
Confidence
Avalanche Summary
On Tuesday and Saturday near Kispiox, several size 1 to 1.5 persistent slabs were triggered by machines. These avalanches mainly occurred at treeline and are suspected to have failed on a weak layer of surface hoar.
Last week, backcountry users experienced whumpfs in the Babines, Grizzly Plateau & Hudson Bay Mountain.
These avalanches and the whumpfing suggest that humans can still trigger avalanches where these layers remain intact.
Snowpack Summary
20 to 40 cm of soft snow exists in areas sheltered from the wind. At upper elevations and exposed areas, this snow could be wind-affected by previous winds. Below 1500 m, new snow overlies a melt-freeze crust.
Two or more preserved surface hoar layers can be found buried between 40 cm and 80 cm deep. These layers are most prominent at treeline and below treeline elevations above 1200 m, but they've also been observed in some alpine locations.
Near Ningunsaw, there may be a crust 100 cm deep that could act as a weak layer.
Snowpack depths at treeline vary across the region with generally deeper amounts (~150 cm) in the west and shallower (~80 cm) in the east.
Weather Summary
Tuesday Night
Clear periods with no new snow. Alpine wind northwest 15 to 40 km/h. Treeline temperatures drop to -15 ºC.
Wednesday
A mix of sun and cloud with isolated flurries. Alpine wind northwest 20 to 40 km/h. Treeline temperatures drop to -25 ºC.
Thursday
Mainly sunny with no new snow. Northerly outflow wind 40 to 60 km/h. Treeline temperatures drop to -30 ºC.
Friday
Sunny with no new snow. Northeast outflow winds easing 20 to 50 km/h. Treeline temperatures around -30 ºC.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Persistent Slabs
Several buried surface hoar layers may be found 40 to 80 cm deep. These layers only seem to be a problem at elevations above 1200 m.
Near Ningunsaw, it may be possible to trigger slabs that fail on a weak layer 100 cm deep.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
In exposed areas, north winds may continue to transport soft snow into reactive wind slabs today.
Aspects: East, South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 10th, 2024 4:00PM
