You can detect severe weather including tornadoes by locating lightning strikes:
Network for Lightning and Thunderstorms in Real Time
The organization is a volunteer, global effort to map lighting strikes.
You can join by making your own lightning detector. Here is a brief description:
Project Description - (14. February 2016, 11:10) Assembly Instructions System Blue - (under developement)
Our newest detector system is called "System Blue". It will replace the former detector system called "System Red". The essential difference between the two systems is the way how these systems are assembled. System Red is a kit with mainly wired components. System Blue contains mostly SMD parts. It will be delivered partially assembled. In addition, the amplifier and filter system have been changed as well as the digital part. System Blue is also prepared for an installation in a compact housing. This is achieved by the dimension of the controller board and the arrangement of the terminals. We will probably start with a minimal basic version similar to that what we are currently testing, see the pictures above. Later on, the system can be extended by further components and adjusted according to the experience acquired.
The current system Red is described here. I mirrored the pdf file to reduce the load on their server and to increase your download speed:
The closest lightning strike I ever experienced was in 1985. I was washing my car in my front yard under a torrential downpour when it struck a tree at the far end of my backyard, 60m from where I was standing. It was LOUD, louder than when a bomb exploded 30m from my house some 15 years ago. My servant, who'd been looking out a back window, said that he was almost knocked off his feet by the shockwave.
But the biggest lightning strike by far in my experience was in September 1984. I was in a friend's house when it struck at about
7 pm. It felt really really close. The TV died immediately. Half an hour later, their daughter cam home from night college half a kilometer away and she said that it felt like the strike was right next door. The next day, I received reports of lightning damage from power stations in various parts of the state, some of them 150 km apart. The strikes all occurred at the same time and everyone claimed that the strike was really close to them.