well im not from coventry, but the climate here west of birmingham is fairly similar to that of coventry. thunderstorms occur here on rare occasions; every now and then, and usually when they do occur, they are quite tame in nature, with occasional hail, moderate gusts, and lightning. however, scattered showers are often the norm when it comes to convection, with light/moderate showers and good sunshine in between, which happens quite frequently. as you have already sussed, our climate is fairly benign and boring at the best of times, with slow moving, repetitive high pressure systems often hanging round for ages when they come along, mixed with changeable low pressure systems, though in summer, they tend to be more slack in nature. the most memorable extreme weather event here is probably the birmingham tornado of 2005, whereby a tornado of f2 intensity ripped through the kings heath and moseley areas, and although it was nothing like a canadian/american storm, it was pretty severe for here. that is very rare in the are though.