I'm going to be cheeky and suggest cropping it right across the middle to lose the blue patch above the main sweep of cloud: *for me* it distracts and makes the sky too complicated, plus it suggests this isn't really a big deal after all.
Thanks for the comments! It was a spectacular afternoon, with big clouds passing by at regular intervals. Regarding cropping across the middle - yes, I can see that would work; I love panoramic format images.
This one was taken four minutes earlier -
Once you start getting too close (metaphorically speaking, that is) you start noticing all the paraphernalia surrounding the stones, but that is another story altogether.
That's a good point; The second was taken about four minutes before the first. In the meantime, I changed my location, and focal length, and the big cloud was moving steadily across the sky. But the light was the same!