So Thursday’s forecast has gone well so far but we are getting to the tricky part.
Today will see more long spells of hot sunshine. Some high cloud at times, particularly this evening, also some fair-weather and mid-level bits of cloud bubbling up. 31’C should be reached – we might get to 34’C.
There is a very, very small chance of an afternoon shower, perhaps with a rumble of thunder, but we are talking 1% chance.
Overnight there is a very small chance of some showers moving up from the south-east, with some thunder also possible. Again, a 5% chance at best, as it stands. Otherwise it will be warm.
From tomorrow through to at least Thursday, the chance of thunderstorms increases, and they could be severe in nature. Frequent lightning, torrential downpours, localised flooding, largeish hail, gusty winds all easily possible. You there might even be reports of a tornado somewhere across England/Wales (they normally only effect very small areas, ie one street or one small patch of farmland).
For Monday, we are looking at more hot or very hot sunshine, at least 31’C, 35’C possible depending on how long it stays sunny for. Around a 25% chance of catching one of these thunderstorms tomorrow.
Such is the unpredictable nature of thunderstorms, you could miss them all and stay dry or at least lightning-free all week. However, it is more likely than you’ll get a few over the course of the coming week, and perhaps some general thundery rain either Wednesday or Thursday.
And they won’t “clear the air”. It is a bit of a myth that thunderstorms “clear the air”. Cold fronts clear the air, and sometimes cold fronts trigger thunderstorms – hence the belief that thunderstorms clear the air. However, if you catch a daytime storm this week, as soon as the sun comes out the temperature will shoot up once more. There is no cold front!
Probably less hot by either Thursday or Friday, though I don’t rule out the heatwave extended through to the weekend – it all depends on what happens with the thunderstorms this week as they likely develop into a low pressure system – and then what that does.
I cannot give you a forecast for Friday onwards yet and I doubt I’ll have the answer by tomorrow evening’s main forecast.