And Another Strange Thing In The Sky That Kind Of Looks Related To The Last Post

Jigsaw clouds -- what could be causing them? Notice how clean and sharp the edges are, at the lowest point of the dip.

Can a 'river' of air become trapped between two clouds approaching each other, acting like a buffer between them? Or is one cloud somehow pushing a layer of air ahead of it as it moves, thereby creating a negative mold of its shape in the other cloud?

Was there a bolus or eddy of high-pressure air moving through a flat cloud, like a ball lightning? It certainly looks as if something formed in that pocket on the lower right and meandered a little before exiting the cloud at the upper left.

Was there an invisible object moving through the cloud?

Edit: It occurs to me that it probably happened in the reverse direction -- that is, whatever it was entered the cloud at the upper left and came to a rest in that pocket; that would explain the increasing sharpness of the trail toward the right. Also, since, leaving a trail of emptiness means the thing was continuously repelling the water vapor around it, it makes sense that there is a larger pocket around the spot where it apparently stopped, stayed a bit, then disappeared (since there is no exit trail). It further looks like once the thing was gone, the cloud was beginning to 'heal' itself -- that is, filling in the empty pocket.