Since 2003, the IEM has been producing a number of RADAR GIS web services allowing for easy access to this imagery in real-time and even archived modes. Perhaps the number 1 feature request I have gotten over the years is the addition of a forecasted RADAR layer.
I've now implemented a workflow to process the "1000m simulated reflectivity" from the NCEP HRRR model into GIS RASTERs and then make these available over WMS/TMS web services. The HRRR model updates a 18 hour forecast hourly with data available every 15 minutes. You may have previously noticed animated GIFs like so before showing this imagery on a static map.
PS. An archive of these animated GIFs exist.
So feedback is certainly welcome and hopefully there is enough detail on the website to get interested folks up and running with the data.