Based on the question and answer here, regarding the uses of Illusory Reality and Hallucinatory Terrain, the question that popped into my mind is:
Are clouds in the sky "terrain" such that they may be the object of those two spells? In some cases flying creatures might treat them as such.
You make natural terrain in a 150-foot cube in range look, sound, and smell like some other sort of natural terrain.
Since clouds obstruct vision and have something in them (even if it's only bits of water) it appears that this spell can change part of a cloud.
You can choose one inanimate, nonmagical object that is part of the illusion and make that object real. The object remains real for 1 minute. The object can’t deal damage or otherwise directly harm anyone.
While this application seems mostly related to aerial combat, or detection, do these spells affect clouds in that way (opening up other useful applications of these spells?) Is there a reason to believe these two spells would not so affect/interact with clouds?