Wind slabs will continue to develop with strong wind. Riders are also still triggering the layer of surface hoar buried around 30 to 50 cm. Such avalanches have the potential of injuring, burying, or killing a person. A conservative mindset is crucial to stay safe out there.
Strong westerly wind will continue wind slab formation in lee terrain features at higher elevations, particularly near ridges. Wind slabs could step down to buried weak layers and form larger avalanches.
Around 30 to 50 cm of snow overlies a weak layer of surface hoar. The layer has been most problematic on northwest to northeast aspects, but avalanches have also occurred on southerly aspects. The likelihood of triggering this layer on Wednesday may increase on southerly aspects due to periods of sunny skies. Avalanches have occurred from 1600 m to 2300 m in the region. Assess the layer prior to committing to avalanche terrain or adopt a conservative mindset to avoid the problem.
TUESDAY NIGHT: Partly cloudy with isolated flurries, strong west wind, alpine temperature -4 C, freezing level 1500 m dropping to 800 m.
WEDNESDAY: Mix of sun and cloud with isolated flurries, light to moderate northwest wind, alpine temperature -9 C, freezing level 1200 m.
THURSDAY: Mix of sun and cloud, moderate southwest wind, alpine temperature 0 C, freezing level rising to 2000 m.
FRIDAY: Cloudy with snowfall, accumulation 10 cm, moderate southwest wind, alpine temperature -3 C, freezing level 1500 m.
A handful more avalanches were triggered by riders on the February 22 surface hoar layer described in the Snowpack Summary. The avalanches were on north to east aspects, they were 25 to 35 cm deep, and they occurred from 1600 to 2000 m. The avalanches were small (size 1 to 1.5).
Similar avalanches have been observed in the region for the past week, being generally small to large (size 1 to 2) and between 1800 and 2300 m on northwest to east aspects. This trend is suspected to continue as this layer slowly gains strength.
Wind slabs may be found in lee terrain features at higher elevations due to wind transport from southwest wind. They may be around 10 to 20 cm thick immediately adjacent to ridges.
Around 30 to 50 cm of snow overlies a touchy layer of feathery surface hoar crystals. The layer is most commonly found in open trees (e.g. in this MIN) or sheltered terrain around upper below treeline, treeline, and lower alpine elevations. Check out the latest forecaster blog that offers a deeper dive into these conditions.
An older layer of surface hoar buried on February 13th now sits around 60 to 80 cm deep. This weak layer has been problematic in the east of the region between Nelson and Kootenay Pass. While it is likely gaining strength, there is uncertainty around lingering reactivity of this layer. Shallower avalanches may have the potential to step-down to this layer.
The remainder of the snowpack is strong and well-settled.
