Time to play the thunderstorm guessing game...
The breakup of cloud over the south from around Bournemouth eastward is still going, and producing some very hot feeling sunshine in places. This may be a result of sunshine 'burning' through the cloud, or descending air from aloft related to the earlier storm systems, or most likely a mixture of both.
A region of convergence continues to bring heavy, thundery rain with embedded thunderstorms along the western flank of this clearing zone - a line running north from the coastal stretch from Weymouth to Poole has been getting hammered for hours on end, including Mattyland judging by his reports...
Storms continue to track North from France and are now starting the channel crossing. An area aiming for the Isle of Wight and Portsmouth looks particularly energetic, and when that reaches land again and encounters a low-level environment heated thanks to those breaks in the cloud, things could get quite explosive... though as always, nothing guaranteed.
Behind those is another area of cloud breaks, and to the east of them is a quite large clear zone heading for the far SE. These look to allow for some afternoon solar input provided storms don't initiate within them before they arrive (models don't see that happening but you know how it is!), and I believe GFS is seeing this, as it shows a marked temperature rise in many areas between noon and 3pm, away from the area NE of London where it seems to have predicted too much heating during the morning - Gravesend would be hitting 28*C by now if it was correct, which looks to be about 4*C too high. I reckon the high 20's temperatures will instead be achieved in the coming 3 hours instead as that clear zone moves over.
It's this afternoon heating that looks to set the stage for the most intense homegrown storms, as GFS shows CAPE peaking between 3pm and 6pm.
The big question then is whether the convective inhibition associated with those clear pockets is overcome by that surface heating. If yes, kaboom, if no, a fine, very warm but relatively quiet late afternoon period could unfold.
Phew. Let's see how that goes
Originally Posted by: Stormchaser