Observations from Winnemmucca Lake

Several loud, propagating whumpfs heard and felt while traveling to Winnemucca Lake and lower Round Top today. Cracking was also common, but cracks didn't travel far from our skis as we were not on steep terrain. Pole probes and mitt pits in sheltered terrain showed 1-2ft of new snow on top of the Dec 11th crust/facets. Winds appeared to have affected new snow depth and distribution even in the trees along our route. Light winds had shifted to East by our arrival in the morning.

At the pin drop, I performed an ECT which surprisingly did not propagate. With the facets 50cm down under a 4 Finger to 1 Finger hard slab, I thought maybe the ECT was the wrong test so I tried a PST. That also did not indicate propagation (PST 80/100 down 50cm on Dec 11th facets). I believe the terrain feature I was on may have been exposed to previous East winds, and did not have as weak of a facet layer as more sheltered slopes in the area.

However, between this morning's forecast and the signs of instability we experienced on the approach (whumpfing and cracking), we agreed not to continue higher even with my test results.

Pic 1: Cracking near our skis even in relatively flat terrain. In several places we got both cracking like this, and whumpfing that propagated much farther than the cracks.

Pic 2: Lots of evidence throughout the area of recent wind loading. This terrain was just uphill of my ECT and PST, and another reason we didn't continue farther.

Pic 3: Interesting mix of surface forms; with graupel, very small surface hoar, and some riming observed - in many places all three were together.