Ah, it's all about the potential
Still really surprised how things panned out today - it was pretty much overcast all day, with a few breaks in cloud from about 2pm onwards. It was still very hazy but all of a sudden heard thunder at around 3:30pm - temps had just hit ~17C. Sure enough, a fairly decent cell had popped up (still not visible as such - couldn't see the tops or anything, which is why it caught me out - but it was certainly darker looking east!), and the thunder was fairly constant to begin with. When I posted earlier, I reported not being able to see any lightning, only hearing the thunder; maybe due to the haze/visibility, but probably beause it was CC (the thunder wasn't very loud/"rumbly", as you'd expect with CGs), but this situation soon changed.
This cell must've initiated in like 20-30 mins, quite impressive. It moved NWwards pretty rapidly - people in MK reporting getting a storm pretty shortly afterwards.
I am definitely pleased (it probably shows!) but that's because 1) it's only April and 2) it's really the first decent storm we've seen here since 2009 - and that's saying something as it was only around for about 10 mins!