Being in 'thunderstorm alley' so to speak, I've learned to be careful ;-). The electronic black boxes are in the garage, out of the rain. They are connected to the mains first through a large surge protector (we do this on all the expensive kit in the house - computers, big TVs etc), and the house has a 'whole house' surge protector. We also have a whole house standby generator, which also has a surge protector. Then, after each session I disconnect the feed from the black boxes to the line that goes to the radio control transmitter/receivers. The power to the tracks goes from the control station to the tracks via two feeds that are capable of being unplugged. - so I unplug them!
Yes, 400+ feet of brass track does act as an aerial for lurking electricity, whether that's coming down (or up) a lightening bolt, spreading out through damp ground or just in the air. I found this out the hard way.
I always, when living in the UK, thought unplugging the TV was my father being paranoid, but living in the northern Gulf Coast I can see what damage even a small blast can do!