A sharp upper trough will approach from the Atlantic on Tuesday night, drawing most low-level air northwards on its forward side beneath cool air aloft. Behind the main frontal precipitation, elements of embedded convection seem likely during the early hours of Wednesday, arriving from the Southwestern Approaches and creeping up the Irish Sea. Instability is marginal, but given steep mid-level lapse rates, upper forcing and reasonable shear, a few sporadic lightning strikes are possible.