Understood on all counts, however, I tried the NOAA station (KSUS) all last season with pretty bad results. There are many times that the area will receive, for example, an inch or more of rain in a period, where, during the same period, I get nothing, and vice-versa. Even the temps can vary as much as 5 + degrees. As noted, my lawn's results from last year were not very good as a result.
I couldn't agree more about dealing with a "hobbyist", but I started using this particular PWS early in the season this year, and it's been dead-on. Also note, that the problem that I've been describing doesn't appear to be from the PWS. His reports over this past weekend show exactly what the actuals were. Only the Rachio app is showing the 64" rainfall..
All that said, and on the basis of your suggestion, I may try to go back to KSUS for a week or two and see what happens, just for the heck of it, although I'm still thinking it's not the PWS that was my problem, but ultimately, what do I know...not nearly as much as I'd like, that's for sure.
It's indeed a mystery to me, but I've made the internal adjustments to the app and am now keeping a close eye on things.