I'm always hesitant to jump to conclusions based on automated sensors, so this discussion should be read with caution. Nevertheless, the radar seems to support the view of a decline in snowfall from Little Cottonwood to Big Cottonwood to Park City. Although this often occurs in NW flow, it's appears to be especially pronounced this afternoon. To show this, I'll show a radar loop in which the high terrain around Little Cottonwood and the Park City ridge line are identifed with red lines.
In the loop below, which begins at noon, note how the intensity and frequency of radar echoes is greatest around and northwest of Little Cottonwood Canyon. Both the intensity and frequency decline as one moves northeastward into upper Big Cottonwood, and then even further as one goes across the Park City ridgeline and finally to Park City and the Snyderville Basin.
One caveat to this analysis is that the radar is partially blocked along the radial that covers Big Cottonwood, so there is some tendency for less intense and frequent echoes there due solely to that reason. Nevertheless, there does seem to be some signal here.
With regards to the decline in snowfall near the top of the Tram, if legit, I suspect it reflects the shallow nature of the storm and considerable snow growth at mid elevations.
Those of you skiing today should add some comments on what you observed.