A few spring to mind.
End of May 99 - Storms moved up from the SW and hit us head-on one afternoon. Day darkness, green swirling sky, rotating ground dragging scud and then the heavens opened with incredible hail, lightning and thunder.
June 2014 and the Bournemouth supercell.
23rd July 2019 - the most recent entry. The lightning was off the hook. War of the Worlds vibes from that one.