UFO?

After driving through some incredible weather, hailstones, lightning, flash floods and bizarre cloud formations, we stopped the car so that Peter could take a picture. I was taking a picture of him with the silo and rainbow behind him, when a black dot appeared in the sky. In a fraction of a second it had grown to the oval shape you can see, and in the time it took me to click the photo, and look up from the phone, it zoomed off to the right and disappeared. I have a photo taken the second before, where there is nothing in the sky above him.