Discussion:
An occluded front will develop into an area of low pressure as it propagates eastward during the day, allowing scattered heavy and perhaps thundery showers to develop widely. Isolated lightning strikes are likely across northern parts of Wales during the morning due to orographic lift; however, the lack of diurnal heating and CAPE will limit the lightning intensity.
During the late morning and early afternoon, the area of low pressure will center itself over East Anglia, creating a cold pool for thunderstorms across Northern England. Meanwhile, a surface convergence zone will develop across parts of southeastern England and East Anglia, allowing heavy showers to develop. These showers are likely to be thundery and perhaps strong and long-lasting due to the moderate deep-level shear and low-level shear. Due to the moderate shearing, rotating updrafts are also possible within these showers, potentially leading to the formation of funnel clouds or tornadoes. Strong CAPE (700-1000 J/kg) will also promote the amount of lightning.
The occluded front across Northern England should clear away during the early afternoon, leaving behind a cold pool. Accompanied by a sufficient amount of CAPE (500 J/kg), isolated thunderstorms should be able to pop up widely. However, due to the lack of shearing, especially across Northwest England, these thunderstorms will be short-lived and sporadic. Shearing will be slightly stronger across Northeast England; therefore, one or two stronger cells might develop in these areas, allowing some frequent lightning locally, most likely along the coasts. Written: @Handry_Outlook