It is generally known that the forces of nature can be destructive, as proved time and again by storms, tsunamis, tornados, tidal waves and earthquakes to mention but a few. Fortunately, the occurrence of these awe-inspiring natural forces is rare. The thunderstorm, a more frequently occurring phenomenon with less impact than any of the above (but by no means less dangerous), is caused by electricity (at an enormous scale), which makes it suitable for detection by electronic means.The author got the idea to design this circuit during an outdoor sports event. Many among the audience were quick to deploy their umbrellas when it started to rain. This happened while a distant sound of thunder could be heard. All of a sudden, a large group of people appeared to throw their umbrella to the ground.