Behind the cold front, which will have brought outbreaks of rain earlier in the day, some modest heating of a residual moist low-level airmass (dewpoints of 11-13C) may provide a conditional risk of surface-based convection across SW England during the second half of the afternoon and early evening. As such, there is a the chance of a few heavy showers/one or two thunderstorms developing here, drifting northwards into parts of south Wales. However, model guidance has been rather inconsistent with this conditional threat, and so confidence is low - but have introduced a low-end SLGT/extended existing SLGT northwards. Regardless, there will also be the risk of some elevated shower/thunderstorm activity during the evening/night hours, which also extends across other parts of southern England (see below) - but the extent of lightning activity is also uncertain.

As the cold front drifts across East Anglia, and more especially offshore over the North Sea, model guidance suggests an uptick in elevated convection is possible through the late evening and overnight hours, and could lead to a fairly active band of thunderstorms well-offshore. Forecast profiles reveal some notable CAPE over the North Sea from parcels lifted from a warm nose in the 800-900hPa layer. There is some uncertainty how much of this lightning activity could develop close to the coast of eastern England as it progresses northwards through the night, perhaps as far north as SE Scotland by the end of Thursday night - but the vast majority of any lightning will likely remain offshore.

One or more waves of shower activity may drift northwards from northern France, affecting the Channel Islands, English Channel and portions of southern England, during Thursday evening and night. However, once again confidence is low on the coverage of lightning given only modest instability. Not anticipating widespread lightning, but a few pockets of sporadic strikes are possible in places. There may also be additional showers/weak thunderstorms that develop further north over north Wales and the north Midlands for a time during the evening/night, but the probability in any one location is too low to warrant a SLGT here.