Seems a bit silly having multiple threads going when it might be quite a lively summer. It looks lively again this week anyhow.
We have met office thunderstorm warnings for the next three days.
www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings#?date=2019-06-23
Tomorrow storm potential looks to be areas away from the SE, including northern England and the Midlands, but I'm also keeping an eye on the SE for tomorrow night. By mid week the storm potential really grows though and by Wednesday we could have some really cracking storms.
Thunderstorms are notoriously difficult to forecast. Not only whether they will happen, but where they will happen. I'll see if I can find the link to the excellent met office tweet about that earlier this week.
It's all being driven by very hot air being drawn up from Africa, through mainland Europe, which could see temps close to 40C. We could see temperatures touching 30C by Thursday. It's going to be humid and uncomfortable I'm afraid.