There are, however, many things that cause glitches on radar displays. Lots of interesting things make signals that aren’t rain: the rising and setting sun, swarms of insects, dust clouds, chaff dropped by military planes. Sometimes you will see a signal radiating from a thunderstorm complex that’s associated with gusty winds propagating away from the storm. You can also see signals coming from storms that should not be seen on the display because they are too far away, but their signals get "folded" into the radar display. I am absolutely certain that the images you have seen have nothing to do with government weather modification.