I stumbled upon this video. Not sure where it was taken, but the person speaks in Russian with Ukrainian accent. In the video he described that for an entire hour he was able to observe a lightning storm, but totally silent one. No thunder and no rain.
Perhaps there is an explanation for it from an "Electric Universe" point of view?
And there is this video of strange clouds, somewhere in Russia, but based on related weather report, it was probably in South Siberian area.
Granted, there are areas in the World, where such clouds are not extraordinary, but they are for this region, and are considered to be very rare. And the thing is that I saw similar clouds very recently during a day with strong winds.