Otherwise, the main focus will be later on Monday night associated with the approaching Atlantic upper trough. To the south of the main backbent occlusion, instability is expected to increase with several hundred J/kg CAPE. Increased forcing as the upper trough approaches from the west may lead to deep convection evolving over the Celtic Sea / S Ireland around midnight, this then quickly extending eastwards towards Wales / SW England during the early hours of Tuesday. 

Given the environment in place - marked mid-level dry intrusion, significant potential instability, strong shear, and reasonable CAPE - some well-organised convection is possible, perhaps even one or two low-topped supercells, which would be capable of producing sporadic lightning and strong gusts of wind. However, there is some uncertainty over the exact forecast evolution, and for now have refrained from introducing a SLGT.