On Wednesday afternoon, a large waterspout formed over Lake Constance, between Germany, Austria and Switzerland.

Waterspouts are essentially nothing more than tornadoes over water. The waterspout was triggered by a violent thunderstorm that lingered over the lake for almost an hour.

Tornadoes typically form in late summer and early autumn, when the water is still warm but the air above it is already cool. However, following the heatwave, Lake Constance is currently exceptionally warm, which has probably contributed to the formation of the whirlwind.