I witnessed an event bearing signs of such manipulation. Although not completely unlikely for the season, two enormous thunderstorm clouds passed over within half an hour, direction north-east. Both clouds were unlikely dense and accompanied by intense lightning and thunder which seemed somewhat exaggerated to me. According to media, the storm also included hail, which I did not see, and caused significant damage to plantations in the central region of Switzerland, the first of august 2017, which, funny enough, is the countries national holiday.