A bit of new snow forecast Monday night in the south and central part of the region will combine with moderate wind to create fresh wind slabs in exposed terrain.
With a bit of new snow forecast for the south and central parts of the region combined with moderate winds there is potential for new wind slabs in lee terrain features. These wind slabs may be sitting on top of weak surface hoar crystals, which would make them more easy to trigger.
MONDAY Night: Flurries with 5-10 cm of snow, moderate southwest wind, treeline temperatures around -10 C.
TUESDAY: Cloudy with scattered flurries with 3-5 cm, moderate southwest wind, treeline temperatures around -12 C.
WEDNESDAY: Mainly cloudy, moderate west wind, treeline temperatures around -10 C.
THURSDAY: Flurries, accumulation 5-10 cm, moderate northwest wind, treeline temperature around -8.
No avalanches have been reported recently. That being said, some notable shooting cracks and whumpfs were reported around Pine Pass last Thursday. They were both linked to buried surface hoar layers, one 30 cm deep underneath a fresh wind slab (here) and the other 65 cm deep underneath old snow (here).
Open terrain is likely being impacted by moderate wind, with wind slabs forming on lee terrain features. Sheltered areas have 10-20 cm of soft faceted snow. Underneath the soft snow and new wind slabs, you will likely find a hard melt-freeze crust up to roughly 1600 m, perhaps weak and feathery surface hoar crystals, and otherwise wind packed snow. Wind slabs developing above surface hoar could be particularly reactive.
There is a spotty weak layer of surface hoar 30 to 65 cm deep in sheltered treeline terrain. This layer has not produced any avalanches to date, but our field team reported some large whumpfs on this layer at Pine Pass on Thursday.
There are presently no deeper concerns in the snowpack.
