https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings#?date=2023-06-25
It seems that Sundays are the day for storms this month, though I know there have been lots of other warnings.
As cooler (not not colder!) weather comes in from the west, heralding a more westerly, unsettled feel for a little while, thunderstorms may develop in the east Midlands through to NE England and Scotland. Torrential rain and other associated hazards are possible.