I do some tower climbing and on occasion have downtime to just gaze up at the sky. Was eye-opening to see a plane go over, contrail form and then see feathery streamers rushing to the sides of it. Freaking thing turned into a cloud over the course of about an hour. And then it happened again as I was wrapping up the job. It's real. Atmospheric conditions must have been perfect for it to form so fast, normally takes a lot longer.

Edit: By turned into a cloud I mean literally. Contrail widened by about 30 - 50(?) times original width, became dense, and had no visible streaking or resemblance to a contrail. Variable wind conditions made wavy eventually, but yeah contrail into cloud, freaky.

I do some tower climbing and on occasion have downtime to just gaze up at the sky. Was eye-opening to see a plane go over, contrail form and then see feathery streamers rushing to the sides of it. Freaking thing turned into a cloud over the course of about an hour. And then it happened again as I was wrapping up the job. It's real. Atmospheric conditions must have been perfect for it to form so fast, normally takes a lot longer.