Through the night and into the early hours of Wednesday, the main area of interest as indicated by the map above is firstly the south west, then extending north into Wales and other Irish Sea Coasts towards the end of the night and start of Wednesday morning, some places here could see high rainfall totals, with strong winds and hail mixed in in places. Another batch of storms may also break out further inland towards the midlands during tomorrow night, these may head northwards towards southern parts of northern England before dissipating.
During Wednesday, during the late morning anyway most of the “storm” activity is forecast to peter out for a time, with just a few rumbles and heavy rain across Scotland, maybe Northern Ireland around lunchtime. After lunch time though and through the afternoon, temperatures will soar which will be the main ingredient for more thunderstorms, hit and miss however some could be fairly intense, locally severe across central and eastern England, perhaps a few popping up across the south to. These storms will head off into the north sea during Wednesday night. There is also the risk of importing an MCS (mesoscale convective system), from France, into Kent/ south eastern fringes of England, during Wednesday afternoon and evening, this is a very low risk however it’s one that needs watching closely, as slight changes in forecast output could mean that this becomes a significant part of the forecast.