Hey thanks everyone!
@Bob: nice idea. It's probably not so easy to do, I don't think I'm going to try it this time, as it would just change the image appearance too much.
@freelancah: I hear you - I thought the same.
@Jack: it's really just the cumulus pack V2 from NWDA, with an extra, lower, softer layer added to the fat cumulonimbuses. But there is also another technique used that is not available yet to everyone.
@Ulco: lighting-wise, I'm attempting to create an image like a camera would expose for it. I've attached an example photo for you. If you expose for a sky like this, the ground gets dark, up to being black. My render is already quite HDR compared to this
I know you like low-contrast images, but then, you rarely make scenes where you expose for the sky with a very bright cloud, which is quite a game changing constraint
Cheers,
Frank