I spoke with AcuRite. They recommend 5in1 model number 06014M ($90) and Internet Bridge model 09150RM ($75). They said that will feed directly to WeatherUnderground.
Now for the challenge of getting to a format Rachio will recognize as a PWS. Very conflicting information on the Rachio site (some say Meteobridge & dlink, some say PWSWeather.com, some say PWSWeather.com & WeatherSnoop (Mac only- which I don’t have)). Wish me luck!
Hallie