Residual warm plume will still be in place across eastern England on Friday morning, albeit somewhat moderated compared to recent days. Advancing Atlantic upper trough will tend to merge with the cut-off low over France, before upper ridging arrives from the west. Forced ascent, as the various frontal boundaries associated with a change in airmass continue to migrate eastwards, will likely lead to a messy mix of dynamic and convective precipitation, but given PWAT in the mid-high 30s and slow storm motion, there will be a risk of localised flash flooding from any embedded thunderstorms that do develop, particularly across East Anglia and SE England - especially first thing around London and neighbouring counties.

Reduced instability overall suggests lightning will not be as prolific or as widespread as seen over the previous few days, and in reality many areas may remain lightning-free within the SLGT. 

Pre-frontal medium-level instability release may allow thunderstorms to affect Shetland at times, depending on the exact positioning of the N-S line of development.

A few heavy showers will also be possible in far NW UK, but the risk of lightning is considered quite low.