A warm but unsettled week, with low pressure developing…though it quickly becomes uncertain as to when it will rain. But it will rain.

Thanks to Andy for the photograph.

So the general set up for the start of the week sees high pressure out to our west, over the Atlantic, and another large area of high pressure over Russia and eastern Europe (confirm Prague was hot and sunny the whole time I was there). And in the middle, a weak low pressure drops south over the UK – which will develop into more of a feature later in the week.

Today starts mostly cloudy with bits of light rain/drizzle at times, and the odd shower. It will brighten up somewhat during the morning, though some scattered heavy showers will develop also. During the afternoon, more in the way of sunshine, still some cloud and a smaller chance of a shower. Warm, we should get to around 22’C. Some cloud and some clear spells overnight, down to around 13’C.

Wednesday starts fairly cloudy, though some sunny spells. Some showers around also – these likely becoming heavy and slow-moving in the afternoon, so catch one and it could last an hour or two, but also this means you may miss them all too. Around 20’C. Further showers or showery rain probable overnight – though exactly where it will develop is uncertain. Potentially heavy/very heavy. Around 14’C.

By Thursday the low pressure is centred over western UK, pulling warmth from the continent into it – and developing further.

Most likely we’ll see showery rain through the morning, if not persistent rain – which could be heavy/very heavy, with a trend to drier conditions later in the day. Around 16’C, but feeling quite humid.

However – the position of the low pressure is still a little uncertain, and hence weather fronts could be further south of us, and we get a mostly dry day, or just a bit of rain at some point. In such scenario, temperatures closer to 21’C – and on the humid side.

Uncertain overnight – the low pressure will likely have kicked off some thunderstorms over the continent, and they may develop into a spell of heavy, perhaps thundery rain – which may then cross the southern half of the UK overnight. Or it may stay to our south. Either way, a warmer night likely, around 16’C.

Friday is also highly uncertain. Where will the rain band be? More likely over southern England, and hence us, so a spell of rain, perhaps heavy and thundery at some point on Friday is the more likely outcome, but with some very warm air overhead it will be warm and humid too. And breezy.

However, again it could be further south – in which case we’d be looking at long spells of sunshine and temperatures around 25’C – or even further north of us, in which case still around 25’C, though hazier sunshine. The wetter outcome is more likely, but it is another uncertain day.

Saturday, of course, is uncertain. The low pressure probably a tad further south, so I’ve got higher hopes for some warm sunshine for at least a chunk of the day, though the chance of heavy showers, perhaps thundery either developing here, or moving up from France, is quite high, later in the day. Temperatures on the warm side, roughly between 22’C and 25’C.

Sunday likely sees the low pressure move back north again towards us, so further rain/showers likely at some point – but details impossible. Who knows, it could be dry. It should still be on the warm side though.

No much confidence on details for next week, though perhaps something notably cooler later in the week.

Next full forecast will be on Friday, the autumn forecast I will do as soon as I get time, but probably this weekend at the earliest.