I saw this cloud formation as I left physical therapy this morning. The local weatherman explained it a bit and I learned this from Google.
Very glad I got to see it and that I had my tiny camera with me!.

A “Hole Punch” cloud is a non-technical name given to a cloud formed from an aircraft dissipation hole or trail. They are also called "Punch Hole" clouds. Rather than extending as a line, Hole Punch clouds appear as a circular or oval hole in a deck or thin layer of supercooled water clouds. They are not uncommon where jet flight paths intersect altocumulus layers. What is uncommon is when they form in a perfect circle that persists for a length of time to be widely observed.