Who knows....
Lifted index looks goodish for EA and SE according to gfs (lifted index is one way of looking how unstable the atmosphere is)
The honest reality is though that I have no idea where any storms will form, but if I figure it out I'll let you know.....
The other unknown is how far cooler air will actually penetrate. It looks like the south won't really cool down much at all. (apart from far SW)
Hot Saturday coming up! 30C in places.