Thanks, Terry! Can you clarify?
What I see in the mid-greys is noise or texture. If you mean something else, how would you remedy it?
Yes, there is texture and some noise. What those middle greys, in the middle of the cloud mass, might benefit from is increased local contrast, just to make them slightly more "lively". Often photographers reach for the Clarity adjustment brush (in Lightroom) to do this. Try this, by painting over the middle greys and adjusting the value whilst examining the photograph on screen. it might just be the answer, but it may also make the greys too salt-and-pepper or grainy looking.
The way I see it, is you want to raise the lighter valleys while keeping the lower values the same. Another way to approach this is by, again, painting over the area with an adjustment brush and using a combination of increased Contrast and, perhaps, increased Highlights.
It's a subtle change you're after, just enough to, as I said earlier and have no other way to describe it, enliven the greys, give them some presence.
Good luck!