During the evening and night hours, an upper low will swing across Ireland, into western Britain later in the night while deepening significantly. This will see an increase in instability, and a steepening of mid-level lapse rates, particularly over the Celtic / Irish Seas and adjacent coasts during the early hours of Saturday morning. Consequently, an increase in deep convection is likely over these areas during this timeframe, although complicated somewhat by approaching frontal rain courtesy of a rapidly deepening low under the influence of the left exit of the strong upper jet, which will essentially restrict the window for potential sporadic lightning. For now, have refrained from introducing a SLGT, but some squally gusts of wind may occur.