Elevated convection is likely to be ongoing across parts of Wales / Midlands and/or SW England, perhaps as far east as The Wash, on Saturday morning, drifting NNW-wards. In its wake, provided there are sufficient breaks in cloud cover to allow insolation, then 800-900 Jkg^-1 may allow isolated thunderstorms to develop during the afternoon and early evening, especially within the SLGT. It appears timing is crucial between the passage of a shortwave trough and maximum solar heating, with an earlier arrival shifting the focus for initiation farther north and probably at an earlier time. It is worth stressing that these thunderstorms are likely to be fairly isolated, with a good part of the highlighted areas likely to remain dry - had storms been expected to form more widely, then this forecast would be upgraded to MDT.

20kts DLS is marginal but may allow some organisation of any isolated thunderstorms that do develop, although the overall risk of severe weather is considered fairly low, with the main threat being from minor surface water issues from heavy downpours (given PWAT 20-25mm). Given expected CAPE and some organisation, then hail up to 2.0cm in diameter is possible from any strong cells that develop.

There is also scope for further elevated convection, in a messy fashion, to either be imported or develop in-situ across Hampshire / IoW / Dorset / Devon on Saturday night, drifting NW-wards towards Wales. Once again, uncertainty exists concerning coverage and lightning frequency, otherwise there would be scope to upgrade Channel coasts to SLGT.