I am neither a meteorologist nor clouds specialist, but I think this is a very nice and large example of a cumulus congestus over the Rhine bridge, when freight train 44692 from Limmattal shunting yard to Schaffhausen-Singen is crossing the river near Eglisau.
For the train and storm chaser. Trains with thunderstorms, dark clouds, rain, lightning, hurricanes - tropical storms, funnel clouds, storm light, rainbows, and snow storms.