https://radar.weather.gov/ridge/standard/ -- I think this is every NWS radar station with a 30 minute animated gif loop, along with the individual frames that make up that loop.

I know it used to be possible to get these same images -- but with the actual radar imagery separated from the base map, didn't have time to find those, but I'd guess they're still around somewhere.

Edit: a bunch of different radar-imagery only layers from each station over a longer time period: https://mrms.ncep.noaa.gov/RIDGEII/L3/

There's an Android app which seems to surface this exact same data: https://github.com/dh4/WeatherRadar

MRMS is generally much better than RIDGE