For the time lapse video, note the natural cumulus clouds forming over the moisture-accumulating mountainous region. With the help of high-altitude aerosols that are sprayed in the sky, leaving behind metallic particles, you will later see "clouds" generated and shaped with NEXRAD frequency. The metallic particles respond to these electromagnetic waves being fed by the NEXRAD station.
On the NEXRAD radar animation, the natural cumulus clouds appear as rounded blobs, whereas the EM-induced clouds are generated and held in place with the NEXRAD frequency at the Doppler station in Missoula, Montana (47° 2' 28" N and 113° 59' 10" W).
|The NEXRAD facility in Missoula, Montana can be found here|