Back in late November/early December we had a long spell of clear frosty weather, very good for the production of con trails. There were long delays on the A6 caused by resurfacing, so I had lots of time to observe the con trails while waiting for a bus to fight its way through
One thing I saw may provide an explanation for my mystery photos. There were 2 trails, crossing each other at angles like a saltire. One, thin & holding well together, was well below the other which was much less defined & cotton-woolly. But the thin one was rising quite rapidly, so that it eventually passed through & was then above, the fatter one. Unless it was an optical illusion, but I think not. I saw no evidence of a kink in either of them though while they were crossing over
The other thing that surprised me about these 2 trails, though it should not have done, was that they were both being blown across the sky. In the time I was looking, which could not have been more than about 10 minutes, the 2 trails moved about a mile to the (east) south east
