Elsewhere, rapid cyclogenesis will occur as a surface low deepens while tracking NE-wards across the Celtic Sea on Sunday afternoon. Strong upper forcing and notable dry intrusion (steepening mid-level lapse rates) may provide enough forcing for deep convection on the inside of the wrap-around, and hence some sporadic lightning is possible despite seemingly weak instability.

The forward side of the next sharpening upper trough will then provide a favourable lifting environment for lines of squally showers to develop over the English Channel, and then push farther inland. Some uncertainty as to how far inland these showers may extend depending on the exact shape of the upper trough, and hence exact direction of the steering flow, but potentially as far north as Swindon - Cambridge - Lowestoft.

Away from the English Channel instability will be weak, but in a strongly-sheared environment this may be enough to compensate to produce a few isolated lightning strikes - and some notably gusty winds.

During the early hours of Monday, increasing instability will develop over and to the west of W Ireland as the next upper trough approaches from the Atlantic. An increased coverage of showers is expected, which may produce a few sporadic lightning strikes.