This being the second instance in a couple of weeks, sort of begs the question of how unusual this actually might be. But, I’ve been a weather geek for most of my life, and do not recall ever seeing this sort of thing until the last several years. I’ve had a few meteorology courses, and to my mind, the two or three cloud formations present in the photo are not possible, side by side, naturally, let alone within a near perfect circle.
A jet didn’t do this. Jets have been around for over half a century. It’s got to be some sort of military tech. That weatherman out in Colorado might not be the nut he’s been made out to be.
His website is down. Must be looking for work again.
It also looks like something headed off to the right, with the outer edges of the cirlce following, somewhat, in the direction of what left it.
A jet may have disturbed the area to cause some sinking of air but the most likely cause is just some cooler air above the cloud deck descended through it. The air warms as it falls and that dries the cloud portin out. It’s a reverse thermal.
I saw these things a lot in Illinois especially after an Alberta Clipper descended over the plains. Cold dry stable air, cloud cover above the inversion and then mixing at the inversion level. The coolest one we saw actually formed right before our eyes as we were outside doing a rawinsonde run.