Avalanche Forecast
Issued: Jan 14th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
bchristie,
Avalanche Canada
Avoid wind loaded terrain, and shallow, rocky start zones. Reactive wind slabs may still exist, and uncertainty about deeper weak layers demands vigilance, and careful terrain selection.
Summary
Confidence
Avalanche Summary
No new avalanches were reported before 4pm on Saturday.
On Wednesday there was a report of a size two cornice triggered persistent slab avalanche running in steep alpine terrain in the southeast portion of the region. There was also a report of a size 2 persistent slab avalanche on a west aspect at 1700 m on Tuesday.
Snowpack Summary
In terrain sheltered from the wind, 10-30 cm of recent snow overlies a layer of weak, feathery surface hoar crystals buried on January 11th. Below 9000 m and on slopes facing the sun, this new snow overlies a thin crust. Recent moderate southerly wind has stripped exposed ridges, and fed wind slab formation in lee terrain features.
Several persistent weak layers may be found in the top meter of the snowpack. These include a surface hoar layer buried on Dec 28 found 40 to 60 cm deep and a facet layer buried on Dec 23 found 60 to 100 cm deep. In alpine terrain, triggering one of these layers is most likely on steep rocky slopes where they present as facets. In treeline terrain, the layers are most likely triggered on steep slopes in open trees where they present as preserved surface hoar.
Weather Summary
Saturday Night
Mostly cloudy. No new snow expected. Light South wind. Treeline temperature around -5°C.
Sunday
Cloudy, possible clear periods in the north of the region. 5-10 cm of snow expected. Light south wind. Treeline temperature around -7°C.
Monday
Mostly cloudy. Possible trace of snow expected. Light south wind. Treeline temperature around -6°C.
Tuesday
Possible clearing overnight, mostly cloudy through the day. 0-5cm of snow expected, possibly 10cm around Stewart. Alpine wind moderate to strong from the southeast.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be especially cautious as you transition into wind affected terrain.
- Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
- Use conservative route selection and resist venturing out into complex terrain.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Persistent Slabs
Triggering persistent slab avalanches remains possible due to several weak layers in the top metre of the snowpack. Facet layers are the primary concern in alpine terrain, while preserved surface hoar layers are the concern in treeline terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Recent southerly wind formed wind slabs in lee terrain. Keep in mind that a wind slab release could also act as a trigger for the deeply buried late-December weak layer.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 15th, 2023 4:00PM
