Visibility V / V
There are already several observations of this flash here. Personally, I noticed the flash indoors. At first I saw a very bright flash and already during the flash a very hard and long roar began. The sound and brightness were so loud that I first imagined it was some kind of ball of light. Immediately after the collapse, there was a commotion from the roof, probably dripping snow or something like that. There was a slight plague like an electric fire outside. On the Finnish Meteorological Institute's website, the lightning was also visible on weather maps.