Would like to have having rolling 3 hr & 6 hr rainfall totals. Storms don’t fall in 24 hr time periods 
Thanks, Joe
but they also don’t fall in 3hr or 6hr periods. It would be hard to automate that so it works for all storms (even those longer than 3 or 6 hours or for two half hour storms within 3 or 6 hours) (not impossible, but hard).
The amount of rainfall is mainly interested for crops, in which case a rolling 3 or 6 hour total isn’t very useful.
But somehow I still like the idea of a rolling total. Perhaps more if it is something like total rain in last event, where an event would be defined as a period of continuous rain with no more than a 5 minute interruption.
That would work. I would think a gap of an hour or two to separate actual storms.
The NWS stations do report rolling rain totals, though.
Joe Dietrick, KC0NOX
Emergency Coordinator, Livingston Co. ARES
Chillicothe MO
Grudgingly sent from an iPhone
you might consider voting for your own request 
. Guess I thought posting it would start with 1 vote. Thanks
Joe Dietrick, KC0NOX
Emergency Coordinator, Livingston Co. ARES
Chillicothe MO
Grudgingly sent from an iPhone
You can get the rain accumulation in the last hour from the REST API. You could probably use something like IFTTT to get this info logged to a spreadsheet. If you have any programming experience or a hunkering to learn, could also write some fairly simple program to do it.
Anything that floods due to the rate it can drain like a creek or gutter could also be of interest. In my display I graph the rain rate to give myself a visual quantity over time.
And if you wish to create a display to suit your specific decay time then there is a thread describing how to import your data into excel.
Thanks to @sunny Excel trick to get data directly from tempest - #13 by sunny
Cheers Ian