The post-frontal environment will then be characterised by increasingly steep mid-level lapse rates and a few hundred J/kg CAPE, as a notable cold pool aloft approaches from the Atlantic atop relatively warm SSTs. Showers will become increasingly widespread on Sunday night, initially over Ireland, but also feeding into western Britain, occasionally organised into more distinct bands as troughs and occlusions move eastwards in the flow. A few sporadic lightning strikes will be possible, particularly coastal parts of W / NW Scotland and NW Ireland. Given steep low-level lapse rates and some backing of the surface winds, an isolated tornado may be possible. Some attention is given to the Celtic / Irish Seas and W Wales / SW England for a few hours late evening / midnight where the environment may be favourable for some supercell characteristics with any convection that can become organised.