Friday 31st July 2020 – Heat & Thunderstorm Update

So it’s midday and already 32.5’C in Reading. 34’C has been recorded in parts of London. 35’C looks likely, if not 36’C.

There will be a bit more cloud around from 2pm, and one or two scattered thunderstorms should break out. I still think no higher than a 20% chance of one.

Interestingly lightning is more likely than heavy rain, as any rain may evaporate before it lands, should we catch a thunderstorm. That said, there is still a chance of torrential downpours, and possibly hail. Overall no higher than a 20% chance that we catch a thunderstorm, I’d suggest 3pm to 5pm the most likely slot, though evening also possible.…

Thursday 30th July 2020

One very hot day ahead. And then a return to changeable conditions.

Thanks to Jonathan for the photograph.

Tonight will be clear, warm and rather humid in a southerly breeze, 18’C.

Friday starts sunny and will quickly become hot, it could be 30’C as early as 10am. A cold front will be approaching from the west later in the day, and there is a small chance, say around a 20% chance of a thunderstorm mid/late afternoon with torrential rain. A similar kind of chance of a bit of rain, and around a 60% chance that it remains dry but with more cloud. As often is the case, the breakdown and chances of any thunderstorms will remain uncertain right until the time.

Maximum temperatures will depend on exactly what happens with this cold front and how much cloud/rain it generates. I expect 33’C to be reached, I would not rule out 36’C. And it will be humid.

However, it will become less hot fairly quickly during late afternoon – temperatures probably peaking around 2pm, give or take. Variable cloud overnight, still warm and humid but becoming less so as the night goes on, 18’C.

Saturday will still be very warm, but nothing like Friday, and we are back in a more westerly flow having lost the southerly.

There will be sunny spells and variable amounts of cloud. A small chance of an afternoon shower. Very warm, around 24’C. Mostly clear overnight, down to around 12’C.

Sunday sees more sunny spells. Some cloud will bubble up, particularly around the lunchtime period, and there will be a small chance of an afternoon shower. Warm, 23’C. Fairly cloudy overnight, probably some rain but the extent and timing uncertain at this stage, 15’C.

Monday is a bit uncertain. It looks like a decaying low pressure will be heading towards the south of the UK, either brining cloud and bits of showery rain – or sunny spells and showers. Rather cool if cloudy, though on the warm side if sunny. It should be mostly clear and dry overnight, around 13’C.

Tuesday is also uncertain – good job I am not planning to do anything more exciting on my week off than clean the fridge. The general pattern looks like a deepening area of low pressure will be heading towards Scotland.

Exactly where the low pressure will be and associated rain fronts will determine our weather – it could easily be 15’C with strong winds and heavy rain, or we could end up very warm and humid with hazy sunshine – the weather front staying to our north.

Guess what? Wednesday is also a bit uncertain, the low pressure probably decaying but bringing some heavy showers, and likely warm.

What I am more confident about (though by no means 100%) is that Thursday will see high pressure in a more favourable position, similar to the end of the current week, allowing very warm air to spread up from the south again.

So the more likely outcome is Thursday sees sunny spells and temperatures around 25’C – give or take a couple.

Assuming we go for this hot southerly plume then the most likely outcome for Friday would be a hot and sunny day. 30’C easily. Maybe more. Maybe I haven’t booked the worst week to have a holiday after all?

At some point under this plume scenario a breakdown will come (thundery?!), but more likely than not the heat will last at least to Saturday.

Not bad for heat lovers or those with trusty air conditioning units.

Have a good weekend…I’ll update on tomorrow’s possible thunderstorm, in the morning, if there is anything to update you on. If you don’t hear from me than I have no further information!…

Monday 27th July 2020

So, can we get to 30’C for the first time this July? It’s certainly going to warm up by the end of the week. Briefly!

Thanks to Jo for the photograph.

This evening sees one or two scattered heavy showers – these will fade to leave clear spells overnight, 12’C.

Tuesday sees high pressure ridging it – the weekend’s low pressure will be heading to Scandinavia, and the low pressure system in the middle of the Atlantic will be what pumps the heat up for the end of the week.

Tuesday itself will start with sunny spells, but cloud will bubble up from late morning onwards – with more cloud than sun for most of the rest of the day, but still bright. 18’C in a cool north-westerly wind. Clear spells overnight, down to around 11’C.

Wednesday starts with sunny spells. Cloud bubbling up again from late morning, a bit less than Monday but still more cloud than sun overall. More sun later in the day, and warm again, 22’C. Quite a lot of high cloud overnight, 14’C.

By Thursday we’ll have high pressure squeezed just to our east – low pressure close to the west of Ireland and a quite hot southerly flow.

Long spells of sunshine all day – just a tiny bit of occasional summer cloud. Quite hot, 26’C likely – 28’C possible. Clear and warm overnight, minimum of 17’C.

Friday morning will see long spells of hot sunshine – 30’C likely, 32’C possible and likely humid. The afternoon and evening may see showers break out – perhaps thundery, but this is uncertain at this stage. A warm and humid night, showers remain possible, around 20’C or just under – a tad fresher by dawn.

Saturday is a bit uncertain due to the usual vagaries regarding the break down of the plume of hot air. It should see sunny spells and it will remain very warm – yet feel much fresher. Around 24’C, give or take.

Sunday looks fine with sunny spells – though more in the way of cloud bubbling up. Around 21’C.

Next week looks mixed – some warm, sunny days – some showery days too. Suggestions of another very warm/quite hot spell for the weekend around 8th August, but it is quite far out to have any confidence.

Overall August does again look rather mixed with low pressure often close to Scotland which does suggest that there will be quite a few spells of showers – but I’m also expecting some very warm, sunny days too – the middle third of August currently looks more likely for the warmest and sunniest conditions, though again I state this with low confidence.

Have a good week.…

Monday 27th July 2020 – Rain Update

Mostly cloudy this morning with showery rain for the next hour or two – some heavy bursts. A short dry spell for an hour or two follows later this morning, this then followed by another hour or two of showery rain – you can see the dry slot on the radar image, with the second band of showery rain over Wales.

Once this clears, say mid-afternoon, there will be some warm sunshine but also a scattering of heavy showers.

Full update tonight.…

Saturday 25th July 2020

I know that July hasn’t been glorious, but there hasn’t been that much rain either, at least in our parts of the world. We should get some today.

Today will often be cloudy – a bit of brightness at times. Some scattered bits of rain this morning but nothing notable.

From around lunchtime we should see some scattered heavy showers developing, but also some general heavy rain spreading up from the south-west.

There is some uncertainty as to how far that heavy rain will get – it may just be the far south-east of England – if it doesn’t get here, we’ll get some very heavy showers anyway, with hail and thunder possible – if it does then we will get more general heavy rain with some very heavy rain possible. Not entirely different either way but one of those where we’ll have to wait to see what happens.

Such is the nature of showers, you might miss them (assuming the rain stays south-east) but unlikely to do so. It will feel warm and humid, especially this morning when it could still reach 22’C – a tad fresher later and breezy too.

Sunshine and showers tomorrow but nothing especially heavy.

I left you with some uncertainty for next week, last time we spoke.

So the likely low pressure for Monday/Tuesday that I spoke about looks like it will spread rain across during Monday daytime – some heavy but also showery. Tuesday being fresher with some sunny spells and a small chance of a shower.

Wednesday sunny spells and warm, Thursday sunny spells and very warm/quite hot.

The other question was the mini-plume for next Friday/Saturday – it does now look like it is on, not certain but probable. So the question is now how many hot days – just Friday? Friday and Saturday? Or could we even squeeze a third day. Uncertain still.

I think Friday and Saturday yes, but with thundery downpours either Friday night or some point Saturday and fresher by Sunday as the most likely outcome right now, but it is still uncertain.…

Thursday 23rd July 2020

Low pressure takes control. Well, it hasn’t rained that much recently, despite the amount of cloud.

Thanks to Andy for the photograph even though there’s a bit too much sunshine to match the upcoming forecast. Though there will be some sunshine…

This evening will be cloudy with the odd spot of rain from a weak weather front as it slowly moves south-east. Staying mostly cloudy overnight, 14’C.

Friday just about stays under control of a ridge of high pressure. Quite a lot of cloud, more cloud then sun overall, but it will be bright with some sunny spells. A small chance of an afternoon shower. Very warm, 24’C. Mostly cloudy and on the warm side overnight, one or two splashes of rain but dry for most of the night, 16’C.

Saturday sees low pressure in control, just to the north-west of Scotland.

The morning looks mostly cloudy, a few bright spells but more in the way of showery rain – some heavy. Perhaps a bit more sunshine in the afternoon but also some very heavy showers around, potentially merging into longer spells of rain – torrential downpours, thunder and hail all possible. Breezy but on the warm side when not raining at 21’C. Heavy showers/showery rain still likely in the evening but slowly clearing overnight, down to around 12’C.

Sunday starts with sunny spells – some cloud but fairly pleasant. The sun will be hazier in the afternoon with a scattering of showers too, but not everywhere getting a shower and not likely to be especially heavy. Warm, 23’C. Clear spells overnight, down to around 13’C.

Monday is uncertain. The general picture is that another area of low pressure will approach from the south-west and bring some rain at some point either Monday or Monday night, and perhaps lasting into Tuesday.

So Tuesday is therefore also uncertain.

Potentially there could be some very heavy rain mixed in and possibly some very warm, humid air too before it rains – but it will be another day or so until the details are ironed out for Monday/Tuesday.

Wednesday looks like seeing high pressure build from the west – not especially warm with a north-westerly flow again, around 19’C with the odd scattered shower, but nothing of note.

Thursday sees high pressure over the UK, good sunny spells, some cloud bubbling up at times and a small chance of a light shower but otherwise a warm, pleasant day. Around 23’C. Low pressure will be close to the west though!

Next weekend is uncertain, though the slightly more likely outcome sees low pressure stalling to our west and allowing a brief southerly flow for a day or so.

Assuming so, Friday looks very warm/quite hot and sunny – 26’C, give or take.

As I said, I doubt the mini-plume will last more than a day, but if it lasts into Saturday then 30’C is possible, but rain and showers will be approaching from the west, and more likely Saturday is wet/showery.

If we do squeeze another quite hot day on Saturday, then most likely we go back to cooler and showery from Sunday.…

Monday 20th July 2020

A fine start to the week with warm sunshine, some showers later in the week – and low pressure in control by the weekend.

Thanks to JoJo for the photograph. Well, for many photographs but I only choose one!

Tonight sees mostly clear skies, down to around 10’C.

For Tuesday we have the Azores High stretching across the UK, bringing further fine weather.

Good spells of sunshine for the morning, but quite a bit of cloud developing from lunchtime and during a good portion of the afternoon – likely rather cloudy, but some bright spells possible especially later in the afternoon. Warm, 22’C. Variable cloud overnight, down to around 11’C.

Wednesday again starts with sunny spells and again sees more cloud bubble up for lunchtime and early afternoon – though not quite the cloud coverage I expect for Tuesday so it should remain bright, and sunshine amounts then increasing later in the afternoon. Very warm, 24’C. Clear spells overnight, some cloud, 13’C.

Thursday is a mostly cloudy day. Some brightness at times, more notably in the morning, but a weak weather front will bring a fairly overcast afternoon and evening – with the odd light/moderate shower possible. Around 20’C. Mostly cloudy overnight, the odd spot of rain possible early on – some clear spells to end the night. Mild, 15’C.

Friday sees sunny spells but also a fair amount of cloud bubbling up – roughly equal amounts of sunshine and cloud during the day. A small chance of an afternoon shower, say 20% chance. Around 22’C and fairly warm. Clear spells at first overnight, cloud thickening after midnight – perhaps some rain before dawn, though timing uncertain. Around 14’C.

By Saturday we have low pressure to the north in control.

Details not determined for Saturday yet, but it looks like a day of sunshine and heavy showers, perhaps with hail and thunder, some chunky downpours also possible. Probably one or two organised bands of showers in the mix. Breezy but on the warm side, 21’C. Mostly dry overnight with clear spells – though still a chance of a shower, 13’C.

Sunshine and scattered showers for Sunday – not confident on details but I suspect less showers around than Saturday. Still on the warm side, around 21’C.

The start of next week will see further showers or perhaps general rain at times, but also some sunshine. Temperatures around normal.

Hints of the Azores High building across the UK, or at least the southern half by the end of next week to bring a warm and sunny spell for the end of next week and into next weekend – though some cloud also possible, as per recent conditions.

Probably quite mixed for the first week or so of August – some showery days but also some warm, sunny days. Hints of something very warm around the middle of August, before becoming more unsettled towards the end.

Low confidence for anything further ahead, a weak signal for a wetter than average September, but I’m not yet fully bought in.…

Thursday 16th July 2020

Starting with a question. What’s your perception of the weather so far this summer? No wrong answers, just curious.

Thanks to Paul for the photograph – nice and horizontal – fits my website perfectly!

There is somewhat more sunshine and warmth in the forecast – the same overall picture remains of the Azores High trying to ridge in from the south-west, with low pressure systems to our north near Iceland occasionally bringing weather fronts with rain and fresher conditions.

Clear spells tonight, particularly late in the night and a warmish night, 16’C.

For Friday we have the Azores High ridging in, bringing the warmest day of the month so far (I think!) – with low pressure close to Iceland which will spread a weather front down from the north-west during the weekend, with fresher air to follow…more on that shortly.

Friday will see good spells of sunshine – there will be some cloud bubbling up, more so in the morning, but overall and especially in the afternoon there will be more sun than cloud. On the hot side, 27’C. Mostly clear overnight, though some cloud towards dawn, 15’C.

Saturday sees a weak weather front slowly edging down from the north-west. Before that arrives, there will be some cloud at times, more likely in the morning, and some sunshine also – which will be hazy at times, especially later in the day. But overall fairly pleasant and very warm, 24’C. The weather front bringing a spot of rain later in the evening, and something more persistent overnight, down to around 15’C.

Sunday starts with some showery rain but this will continue to clear south-east during the morning. Likely a fair amount of cloud to follow, but I’m hopeful for some sunny spells as the afternoon goes on. Around 20’C. Mostly clear overnight, down to around 11’C.

By Monday we are back to the Azores High making another attempt to push in – though with fresher air having migrated down from the north-west.

Decent spells of sunshine, particularly in the morning – there will be some cloud bubbling up, more so for the afternoon. Pleasant at 21’C. Mostly clear overnight, down to around 11’C.

Tuesday will be similar, some decent spells of sunshine but also some cloud bubbling up, more notably during lunchtime. Around 20’C, which is a few degrees below average for the time of year. Mostly clear overnight, down to around 9’C – rather cool for the time of year!

Wednesday sees high pressure over the south of the UK. Good spells of sunshine, some cloud around but not that much, warm at around 23’C. High cloud overnight, 13’C.

Thursday should see high pressure cling on, but I’m not 100% confident. Assuming so, then expect more warm sunshine and temperatures around 23’C – give or take.

Confidence is breaking down by this point, though I think the more likely outcome is that low pressure will arrive from the west either Friday or Saturday, to bring more in the way of rain or showers for the weekend.…

Monday 13th July 2020

Our stuttering summer continues – definitely an improvement of sorts this week, though more cloud and a bit of rain at first – warmer and sunnier by for the end of the week.

The overall picture remains one of the Azores High trying to build from the south-west but the jetstream relatively close to our north (though meandering plenty), which is bringing occasional weather fronts and varying temperatures.

Thanks to Jo for the adorning photograph.

This evening will be cloudy with some showery rain – a few heavy, perhaps very heavy bursts mixed in later, though some places just seeing light/moderate rain only. Rain becoming generally more light and patchy after midnight. Around 14’C.

Tuesday will be rather cloudy, but there will be some sunshine at times. Likely to start overcast with the odd spot of rain, and a light shower is possible at any time during the day, though it will be mostly dry. A north-westerly breeze, around 21’C. Fairly cloudy overnight, 12’C.

Wednesday starts quite cloudy but with a bit of sunshine, it will quickly become overcast and stay like that all day. A bit of occasional light rain in the mix too. 19’C. Variable cloud overnight, 14’C.

Thursday starts to see an improvement as the Azores High makes a more substantial build over the south of the UK.

However there will still be more cloud than sunshine. Starting rather bright, likely becoming mostly cloudy, but then a bit more brightness as the afternoon goes on. Warm, around 23’C. Clear spells overnight, 15’C.

Friday sees further improvements (assuming you like sunshine/warmth), still quite a lot of fair weather cloud around especially around the lunchtime period, but there will be more sunshine than of late, and temperatures getting to the quite hot range, say 26’C, perhaps more. Clear spells overnight, 13’C.

Saturday looks like a fairly weak weather front is going to slowly push down from the north-west, but timing is uncertain. Before it arrives potentially warm and sunny (unless it arrived early morning!), fresher and sunny once it has cleared – and cloudy with bits of showery rain for the spell where it is overhead. Feasibly it could arrive any time from early morning, up to evening. There is even a small chance that it may not arrive and we hang onto the quite hot conditions.

Sunday should therefore be sunny and fresher, with fair-weather cloud and temperatures around 22’C. This does assume on the weather front having crossed during Saturday.

Next week should see yet another attempt at the Azores High to build over the UK! Expect more warmth and sunshine, but don’t expect perfection – there will likely be further interruptions from weak weather fronts.

Hints of something more broadly unsettled around next weekend – though that is some way off, and has little confidence at this stage.

For the very end of July and first part of August, we should go back to a similar pattern to now, generally settled but some cloudier days, occasional weak weather fronts, but often sunny and warm.…

Thursday 9th July 2020

Time to switch summer back on. Kind of. There will be interruptions though…don’t expect glorious sunshine.

No photographs. Not even a barely useable one! Pah. I’ll just use the rain radar instead.

So you can see that there is still bits and pieces of rain around this evening – most of it is light but there are one or two heavier bursts around. This continues all night though becomes more patchy as the night goes on. Quite humid at first, down to 13’C.

Friday starts cloudy, perhaps a bit of rain still. The sun should quickly come out with fresher air arriving from the north-west. Sunny spells, fair weather cloud and a 40% chance of a shower for the rest of the day. We might squeeze 20’C though I feel that is ambitious. Mostly clear overnight, down to around 9’C.

Saturday sees the Azores High spread towards us – summer! Ish.

It starts sunny, but cloud will bubble up by lunchtime – it will still be bright with some sunshine, albeit with plenty of mid-level cloud. A very small chance of a stray light shower. 20’C or just under. Not amazing – but not dull and drizzly! Though I quite like drizzle. Anyway, variable cloud overnight, down to around 10’C.

Sunday sees high pressure in control and warmer air sneaking in. A sunny start, there will be cloud bubbling up – likely more cloud than sun through the lunchtime period, before the cloud slowly reduces during the afternoon. Very warm, 24’C. Variable cloud overnight, down to 13’C.

Monday still has high pressure over the south of England. It starts sunny, though it will become increasingly hazy during the afternoon as a very weak weather front approaches from the north-west – a small chance of a light shower later in the afternoon as it approaches. Very warm, around 24’C. This very weak weather front crosses overnight, bringing cloud and a bit of patchy rain, 14’C.

Exact details for Tuesday are not nailed down, but broadly speaking, more cloud, some sunshine and some showers around. A bit fresher but still warm, 22’C. Cloudy and warmish overnight.

For Wednesday it looks like we’ll see low pressure close to the north of Scotland, but exactly where is uncertain and this will have a big impact on the conditions here.

The model marked UKMO in the top-right corner, ie the UK Met Office, suggests high pressure hanging on so another very warm and sunny day. Yet other models are different – the one marked ECM which is generally very trustworthy suggests low pressure close by, which means at least cloudy, but perhaps with some rain.

The ECM route would also take us into a few cooler and showery days – but followed by a build of high pressure from the west, and more warmth and sunshine. I think this outcome is around a 30% chance.

So for Wednesday around a 50% chance of very warm and sunny, 20% chance of rather cloudy and warm.

And until we sort out this low pressure system near Iceland on Wednesday, I’m not sure what route our weather will take for the few days after.

I do think we’ll end up with low pressure over Scandinavia and high pressure over the UK by the week after, perhaps even by the weekend, which isn’t an especially hot set-up, but should end up quite hot – it is July, after all, so 25’C to 28’C…and the first couple of days being only warm. And generally pretty sunny but not without interruption from the odd weak weather front or a day or so of scattered showers.

It’s just Wednesday to Saturday/Sunday next week that is the tricky part and I don’t yet have a more likely outcome.