I saw another clip, but it showed someone with a tablet inside the heli. Still not sure what it is.

Looks like when you seed the clouds with magnesium and ignite it it catches fire that creates a hot steam that expands rapidly like a pan of super hot oil when you dump a cup of water in it.

The rapid expansion of the water molecules hitting each other causes the rain to pour down in a minute like this unlike its natural state where it slowly binds with each other to create rain.

Where some see weather,
I see Galactics BBQing Lizards.

It feels 'reversed' to me, as in the video is playing backwards (sound seems legit).

Any 'sauce' on the authenticity or who shot it/when it was shot.

Don't interpret this as questioning you, I've seen this for a few days - but only the video. Looks more than a Project Blue-Beam exercise/performance either way.

1. Video manipulation (reversed w/audio track overlay)
2. CGI
3. Real

Dunno, totally.