From Met Office:
Although there remains significant uncertainty in location and timing, areas of thunderstorms are expected to move northeast across parts of England and Wales from late Wednesday through to Friday morning. Whilst not all locations will be affected, some intense thunderstorms may occur during this period with torrential rain, hail, frequent lightning and strong gusty winds possible. Rainfall totals of around 30 mm could fall in an hour, with some locations potentially receiving around 50 mm in 2-3 hours, although these will be fairly isolated.
