looks to me like you have a high intensity, moving, light beam in the shot. It all seems to originate from a specific point amongst the buildings. I live by a beach and see such things as part of light shows. Across the estuary from us (about 20 miles away) is another seaside resort (Blackpool, UK, famous for light shows) I can see their light beam displays from my house.
It doesn't look like it was on for long, just a few flickers across, but it may well be that your aperture stopped it showing unless it was pointed right down your lens.
The weird thing is that the beam seems very concentrated, any pattern that takes place in the angle of hitting your lens wouldn't show up as movement at the other end. Maybe it was a just a particularly bright light source, stationary, but on a mast and as the wind moved the mast it drew those patterns?
Definitely looks like a strong light source in the shot caused this, one way or the other. If you go back and look at that part of the shot again, at night, you will probably spot what caused it.