Fresh wind slabs will start to build on Wednesday and could be more reactive in the afternoon with the accumulation of new snow, especially where they overload a buried surface hoar and/or crust layer.
Moderate southerly wind will redistribute the recent snow and form fresh wind slabs in lee terrain in the alpine and at exposed treeline. Wind slabs will particularly be reactive anywhere they overlie surface hoar that was reported to be widespread in many sheltered areas. Loose-dry avalanches (sluffs) are likely in steep and wind-protected areas.
Wednesday: Mix of sun and cloud with light snow up to 5 cm. Alpine temperatures near -6 and ridgetop wind strong from the West. Freezing levels 800 m.
Thursday: Mix snow and rain up to 20 mm. Alpine temperatures near -5 and freezing levels 1200 m. Ridgetop wind strong from the northwest.
Friday: Mix of sun and cloud. Alpine temperatures near -6 and freezing levels in the valley bottom. Ridgetop wind strong from the northwest.
No recent avalanche observations were reported on Tuesday. A few small loose dry avalanches (sluffs) were triggered by skiers and released naturally on northern aspects in the alpine in the last couple of days (see this valuable MIN report).
Wind slabs will likely be more reactive later in the day on Wednesday with new snow accumulating and strong winds.
Up to 10 cm of new snow fell by Tuesday afternoon bringing 20-40 cm of accumulative storm snow from the past week over a variety of old snow surfaces. These old surfaces include surface hoar in locations sheltered from the wind at all elevations and was reported as widespread, surface facets, and stiff wind affected snow. On solar aspects, a buried sun crust can be found and a thick crust exists near the surface below 1000 m. Additional snow and wind through the forecast period may stress these potentially weak interfaces.
The lower snowpack has two decomposing crust layers that have been causing a deep persistent slab problem for most of the past month, however no notables in the past 2-3 weeks. The upper crust is 70-140 cm deep in the Smithers area and continues to show occasional hard sudden results in snow pits. The deeper crust at the bottom of the snowpack continues to be a problem in shallow ranges like the Babines. These layers seem to be unreactive under the current conditions, but shallow rocky slopes should still be carefully assessed and approached with caution.
