Monday night, while working at my computer, a strong thunderstorm moved through this area, which is a very damp valley leading to the Loch Raven Watershed area in MD. Hearing several thunderclaps seconds after flashes, I considered shutting down my computer and disconnecting the power cord and phone line. A few seconds later, I saw a bright flash and an immediate loud "boom", and all power went out. I smelled something that could have been ozone or burnt phenolic. I set up emergency lighting, looked for any signs of fire, and took a brief look outside. Electrical power along the road up to the junction with a main three phase feeder was out, and both my phone lines were dead. Luckily my pets and I were not.
BGE arrived about 5 AM the next morning, determined that a fuse had blown, and power was soon restored. When it was light enough to see, I looked for other signs of damage outside. I have two houses separated by about 80 feet, and at the corner of the second house (used for storage) stands a huge Sycamore tree, probably 150 feet high. I found some wet, broken branches, and some pieces of bark, but no signs of major damage. However, I noticed that several panes of glass in a window just about two feet from the tree were broken, and two of them appeared to have blown outward. It looked like a raccoon may have jumped through the glass (which is possible, as I have found them in that house). Also near the tree is a 240 VAC twisted utility line, actually touching the tree at one point, and a drop cable to a meter box which is disconnected. I do have power to the house through a UF cable for convenience, fed from my residence on two 20 amp breakers. Also just below the power line is my active phone line, which connects to an interface box and then through a four wire line to my residence.
I discovered that one of the breakers had tripped, and I reset it with no problem. There was a second storm in the afternoon that caused loss of power again, but it was soon restored. The telephone technician found 48 VDC and a dial tone on one of the pairs, but not the other, and replaced a blown protector device which restored one line, but the other seemed to be an open circuit to the pole. An access box on the pole was open, possibly from the lightning strike or perhaps it was being repaired by another technician.
The damage to my equipment included a blown modem in my computer, damage to my computer speaker internal amplifier, and a damaged phone answering machine. I feel lucky.
I don't know the exact path of the lightning, but I think it may have hit the 15 kV (probably) main line and arced over to the transformer secondary and over to the tree, where it traveled down the ground paths. I think a direct hit to the tree would have caused more damage. I am curious about the pattern of the broken glass in the window, however. At first thought, I would expect lightning to ionize the air and create steam pressure from rain, so it would be an explosion with outward force. I think this caused some of the initial damage to the window, as evidenced by glass shards inside the house. But I think this may have been followed by a partial vaccuum that caused the sudden expulsion of higher pressure air in the house through the cracked glass. I will take pictures of it before I repair it.
It was almost prophetic that I was just reading some posts in SED referencing high voltage arcs and lightning, and also now reading the other post about conductivity of trees.
Now it's raining again, and I think I hear thunder.. AIEEE!
Paul