In last nights weather forecast, there was only the remote chance of a thunderstorm in the Twin Cities Metro. No severe weather was forecast.\n\nI was in my theater last night and watching via my HTPC. It was after dark and the blinds were down.\n\nAll of a sudden, there was the loudest thunder clap I have ever heard, just microseconds prior, there was the sound of a large arc, and then a lightening flash and at the same time the enormous single thunder clap. There was no gap between the lightening flash and the thunder bolt. That was the only thunderclap close, but there was some lightening far to the north. There was a brief burst of very heavy rain following the lightening flash and thunder. The three theater UPS units reverted to battery momentarily. The HTPC malfunctioned, but was able to be rebooted, and has fortunately worked perfectly since. My wife was using the the 3.1 system in our great room downstairs. She reported that the power in that system briefly switched to the UPS battery.\n\nI inspected the whole house surge protector at the main switch and breaker at the service entry on the East side of the house this morning. The surge protector indicated it had taken the hit, and needed replacing. I have sent for the electrician to perform that task.\n\nNormally if there is very severe weather I go to generator. In the 15 years I had surge protectors and UPS units at the lake, I would not infrequently go to generator, and power cuts in storms were not infrequent and we had miles of above ground cable. Here in the metro, we have underground service. In almost three years we have only had two power cuts. One was related to severe weather, and the other because a squirrel shorted out a power transformer.\n\nI hate to think what would have happened without the high level of protection we have here. Nothing has had any damage done. However, I think without the protection I have engineered in here, results would have been very different with serious damage.\n\nI am pretty sure this house took a direct hit, and I'm glad that it is a concrete house! From the ground I can not see any roof damage.\n\nI report this incident, to make the point that lightening can be very unpredictable. So this reinforces my view that actually all houses need protection now, with whole house surge protection. It is not just your AV gear, but pretty much everything electrical has complex electrical boards. That now includes Internet infrastructure, ovens, cooktops, micro waves, HVAC, fridges, washer, dryers and more. The losses can really mount to staggering dollar numbers in the modern house.\n\nWhole house surge protection at service entry is essential now, in my view. I think it should be code. For your fragile AV equipment, UPS units are strongly recommended. Insurance claims are a real hassle, and with the cost of home insurance premiums, I suspect most like me, carry a significant deductible.