Here is a short video showing someone doing almost exactly this: https://m.youtube.com/watch?v=X_2lZqyCmls
Point being the initial path creates a plasma channel that then bridges the gap and lets current flow.
https://www.youtube.com/watch?v=gOT8jx4jEzM
Is the arc dissipating because an automatic system is killing power to the lines? Is there going to be damage elsewhere in the system from events like 3 and 2 in the video there?
https://en.wikipedia.org/wiki/Thyratron
Here is a short video showing someone doing almost exactly this: https://m.youtube.com/watch?v=X_2lZqyCmls