Not sure what your asking, but the shadow is generated real time.
HiTech
It's hard to figure it out because you have a layer of clouds. If the layer is missing one cloud, is there a 'hole' in the layer's shadow or is it a generic real time shadow for the layer of the cloud. If you have only one cloud, is the shadow on the ground have the shape of said cloud?
To go further and I know you usually do not answer 'direction' questions but in case

: are you hoping to go deeper with the clouds? As of including CB shape clouds and have turbulences inside of them. (not that I think it'd bring anything to actual gameplay).