I can relay my experience with ET: my weather station is marginally good at temperature and useless at wind (a big factor for ET here with persistent north winds in the summer). I’ve no idea how good the solar radiation sensor is. My Ambient station will not go over 15 MPH, while a correctly set-up and maintained NOAA station 35 miles north is clearly reading 25+ MPH or gusts above 25 MPH. And that’d be what I’m actually experiencing at my location. I would not want ET to be calculated using my weather station… since my trees would get cumatively underwatered big time. I’m just too lazy to deal with the wind instrument issues. But I am absolutely interested in my rain gage working since that is critical information for irrigating my trees, especially in the spring when transitioning to the hot, windy dry season.
I think at one time a bug caused my PWS station to be used for ET. It was a big, meaningful difference when comparing to a reliable State of California CIMIS station about 30 miles south of here. The incorrect ET also didn’t meet my subjective perception of the weather. We nuked that bug.
Anyway, if a PWS is to be used for ET, it need be “pro” hardware, well setup & calibrated instruments used for calculating ET, and regularly maintained. I’m happy to let NOAA do that but I’m sure there are a few great PWS’s out there with excellent, knowledgeable people maintaining them. This user is not one of them lol. I just make sure my rain gage is functional.