Very large, recent natural avalanches on McDonald Peak in the southern Sawtooths...several smaller wind slab avalanches releasing at/near ridgelines in the Smoky and Sawtooth Mtns (cornice fall triggered some)...pinwheels and rollerballs on some steep southerly-facing slopes. The little storm a couple of days ago and wind transported snow over the past 36 hours was enough to keep the snowpack very much on edge.
Fair amount of evidence of recent wind transport in upper elevation terrain: dunes, pillows, cornice fall, etc. No active wind loading or transport occurred from noon-4PM today.
Dec 20, 2021
(+/- 1 day)
|D2.5||HS-Hard Slab||O-Old Snow||N-Natural||Report|
Prairie Ck and West Fork Prairie Ck
|D1.5||SS||S-New Snow||N-Natural||Several D1-1.5 wind slabs, releasing at/near ridgeline or where small cornice fall hit the slopes below.||None|
The light was flat in the northern Sawtooths, but I think I saw fresher slides near Decker Peak, Merritt Peak, Crooked Ck, and McGown Peak.
Roadside observations: Steep solar surfaces were moist or crusts in the process of refreezing. Many locations had small surface hoar crystals on the surface, but I didn't see any larger than about 3mm. I did not much SH that was standing upright.