The map is automatically updated every 15 minutes and shows the lightning recorded by an antenna located at the Pre-alpine Geophysical Centre (Varese). The location of lightning could be subject to a few mistakes, especially along the Alps because of a variable attenuation of the signal due to the mountains. The upper left pane indicates the number of lightning registered during the last minute.
The lightning are indicated by small spots (from cloud to ground) or crosses (from cloud to cloud).
The different colors indicate the recording time of lightning.