An upper trough will be situated across Britain on Tuesday with a reinforcing sharper upper trough approaching Ireland from the northwest later in the day and overnight into Wednesday. Scattered to numerous heavy showers and thunderstorms are expected to develop across northeastern Wales through much of England (apart from far western areas) and into southern and eastern Scotland by late morning and through the early evening. 

Much like previous days surface convergence will be the focal point for shower development, and this is particularly the case for showers that develop from N Wales across to eastern England and northwards into southeastern Scotland during the afternoon and early evening. The shortwave trough axis and associated PVA will drift eastwards across S/Cen England towards western parts of E Anglia during the late afternoon and early evening perhaps giving a slight uptick in lightning potential in these areas later in the afternoon. 

CAPE amounts of 500-800 J/kg will develop widely in the SLGT area by midday and into the afternoon. This combined with PWAT values of around 30mm and surface dewpoints of around 15-16C indicate humid air in place and due to the slow-moving nature of the convergence driven convection, some localised spots could see 50-70mm of rain in a short period leading to the risk of flash flooding. There is little to no shear present so updrafts may be relatively short-lived, although outflow from developed storms combined with further convergence may help to develop daughter cells in the vicinity mature storms. 

Severe weather will be limited mostly to flash flooding, although some small hail may be possible in the tallest thunderstorms. There may also be the risk of some funnels or a brief tornado in the early stages of more vigorous convection during early afternoon.