Yes. I worked for a city and was tasked with occasionally reading emails that had been reported. I got to read some interesting ones, but the one I’m talking about: The auto-theft detective was informing patrol officers about the setting up of the device I described. It would send an email when a vehicle’s license plate was scanned and was returned with a STOLEN result. The majority of the email was about how the officers should not mention the device and only say that they had received a tip about a stolen vehicle.
We aren’t talking about the permanent sorts of signs, like those described by @[email protected]
The evidence I’d add to that is it seems to start in the middle of a section of clouds, and then slowly change the width of the disturbed area. If the line makes that hard 90 degree turn that OP mentioned, it could be the final descent pattern of a plane landing at an airport.