@dan-easton - What about experimenting with some of the maps at this source below and seeing if you can establish correlation? Maybe a certain amount of soil moisture anomaly would correspond to puddles? NOAA also might have other sources you could find helpful. well. Their hydrological modeling is extensive. You might even try a call to the local wx office, as each office sometimes has their own wx and hydrology tools/outputs available for public use (put on their local page, actually). At least, it used to be that way about ten years ago or so. I assume not much has changed with that. The wx office page on the NOAA/NWS site or the local office phone number would be your best bet for such a contact.
Here is the most relevant source I found with a quick search: https://www.cpc.ncep.noaa.gov/soilmst/index_jh.html
Again, maybe it's not acculumated rain in the latest 1/2 day increments, but it is a start.
