Another hot and humid day, with chances of thunderstorms.

It starts cloudy, a couple of thundery downpours have already broken out, however this short band of storms will continue to move west/north-west and there will be good spells of hot and humid sunshine for the rest of the morning, albeit quite hazy at times. Temperatures should reach 28’C, if not 30’C or a tad more – and 28’C should be enough to fire off thunderstorms any time from early afternoon onwards.

It’s likely that they will first form in what is known as “convergence zones”, where winds from two directions meet and force the air up, and hence create thunderstorms, and exactly where these will be is uncertain at this stage, but should be somewhere over the south of England – and I’d suggest this is slightly more likely to our south, and they will be slowly moving west-north-west. So around a 50-60% chance of a thunderstorm or two this afternoon.

In the evening, there are suggestions of more widespread thunderstorms across the Thames Valley.

Main risks are localised flooding from torrential downpours and fairly frequent lightning. There is also a lower chance of largish hail and strong wind gusts.

Full update tonight – there will be more heat, humidity and thunderstorms in the forecast, though the very hottest conditions should now be over.