A mix of sun and cloud on Thursday will switch to snow just in time for the weekend. Concern for a buried weak layer continues to warrant careful terrain choices.
New snow falling with wind has promoted fresh wind slab development. The new snow now obscures widespread lingering wind slabs that formed last weekend.
It remains possible to trigger a weak surface hoar layer buried about 100 cm below the surface. Convex rolls at treeline and below treeline elevations are the most likely places to trigger this layer. Recent reports suggest this problem is more prevalent in southern parts of the region.
WEDNESDAY Night: Mainly cloudy, light wind from the northwest, alpine high temperatures around -20 C.
THURSDAY: Mix of sun and cloud with some light flurries of snow, light wind from the west, alpine high temperatures around -17 C.
FRIDAY: Flurries, accumulation 5-10 cm, moderate wind from the west, alpine high temperatures around -19 C.
SATURDAY: Flurries, accumulation 5-10 cm, moderate wind from the northwest, alpine high temperatures around -25 C.
There is no new avalanche activity to report from the past few days.
That being said, there is still concern for triggering a weak layer of buried surface hoar. Several large persistent slab avalanches were reported on this layer last week. As the layer gets buried deeper it becomes less likely to trigger, but the consequences of doing so are high.
5-20 cm of new snow falling Tuesday into Wednesday now sits above previously heavily wind affected snow.
The main layer of concern is a feathery surface hoar layer that was buried around Christmas and is now resting about 90-110 cm below the surface. While this layer was very reactive across the region last week, recent reports suggest that it's reactivity is localized to certain parts of the region. There has been more recent evidence of this problem in the southern parts of the region around McBride and the McGregors, but preserved surface hoar could potentially be found on sheltered convex slopes anywhere across the region.
