My kind of day! I don’t know what the cloud is like in Reading, but in my corner of NW London it is certainly bubbling up.
Thundery downpours have broken out in a few places already, and will continue to do so through the afternoon and early evening. I do think the greater risk area is roughly between London and Peterborough (both for higher chances of a thunderstorm and higher chances of severe weather in a thunderstorm), but we are in the game also, and I’d still suggest around a 30-40% chance of a thundery downpour.
For the next couple of hours, storms will probably be quite brief – building up, then fading away very quickly. But later in the afternoon they should be able to survive longer.
Large hail, gusty winds, torrential downpours, flash flooding and frequent lightning could be in the mix, or any combination of those.
But remember, you are more likely to miss them and stay hot and sunny (with some gorgeous clouds) than to catch one – but catch one, and you’ll probably know about it!