Very calm quiet day with great visibility. No wind xport, had to search hard for the slightest puff of wind. Temperature inversions and a bit of moisture in the atmosphere were the only notable weather factors. Temps stayed cold in the valley all day. Near and above treeline warmed significantly relative to the valleys and received quite a bit of sun for the time of year.
Dynamic cloud cover- Valley fog to 6500 in AM, dropping to valley bottom around 11a. By 12p a thick band of "upper level" clouds capped most ridges for about an hour. Finally all clouds cleared for blue-bird conditions till sunset.
A few small, older, natural slab avalanches from roughly 11/30 above treeline. D1 x3. WNW, 7,400ft. See photo
Signs of instability:
- A large collapse, propagating 10m, in an area of patchy, older wind-drifted slabs (~10 days old) sitting on 1.0mm mid-November facets, roughly 30cm above the ground. Snowpack was 90cm deep and void of any crusts. 7,600, SW. See photo
- Cracks shooting through very thin, 5cm, recent wind slabs 7,500ft and above on SW. Any resulting avalanche, may not have been big enough to knock a person off their feet.
-Predictable, but terrifying whumphing collapses, propagating 20m in the valley bottom. One smaller collapse was @ 5400ft, W.
-Sudden test results on the mid-November facets in the lower half of the snowpack. 6540ft, WSW.
Height of snow:
Profile- 6540ft, SW
55-53cm crust, Nov 25
@ 53cm CTM (RP), CTH(RP), variable resistant results
46-40cm P+ hard, crust, Nov 22nd
@ 40cm, 4F hard, 1mm, "mid-November" facets, CTH 21, 26 (SP), variable sudden results