Thursday 30th April 2020

Well we managed one day of April showers in April – further showers in the forecast but certainly less so than the last few days.

Thanks to Paula for the photograph.

So we start with low pressure over the UK.

Blue denotes lower pressure on this chart – not colder!

The main bulk of showers have cleared east, still a small chance of catching one this evening, and a very small chance of a passing shower overnight – otherwise variable cloud and down to around 6’C.

Friday sees further showers. Less of them than today, no guarantee of catching one but most will catch at least a couple. Again they could be heavy with thunder, perhaps hail mixed in. There will also be more in the way of sunny spells, and we should get to around 15’C. Clear spells overnight, down to around 5’C.

Saturday starts sunny. Cloud will bubble up during the morning – a bit of uncertainty as to how much, potentially rather overcast but still kinda bright. One or two scattered light showers. Increasing amounts of sunshine later in the day. 16’C or so. Variable cloud overnight, down to around 5’C.

Sunday starts with sunny spells. Cloud gradually thickening during the afternoon but remaining bright with hazy sunshine at times. Feeling warmer, 18’C. Fairly cloudy overnight in a light southerly breeze, 8’C or so.

You may remember me talking about the expected Spanish Plume during the last forecast. By Monday, temperatures will have shot up in Spain itself, yet high pressure building over Scotland looks like it will scupper the heat from making it here.

The oranges denote higher pressure – not higher temperatures!

So Monday will see high pressure building. Some sunny spells but also some cloud likely, again more likely to be rather cloudy during the middle portion of the day. Reaching somewhere between 16’C and 18’C and a very small chance of a light shower. It should be dry overnight, down to around 6’C.

Tuesday is quite uncertain, and will depend on how the attempted Spanish plume and build of high pressure to our north develop. The somewhat more likely outcome is sunny spells, around 16’C with scattered showers. Could instead be rather wet with rain moving up from the south-west – or indeed warmer with sunny spells.

Wednesday is a bit more nailed down – the most likely outcome sees high pressure to our north-east, low pressure quite far to our west. Sunny spells and around 18’C – give or take a couple.

Thursday and Friday probably stay under the influence of high pressure, with sunny spells and temperatures back to around 20’C. A small chance of a heavy shower. Note I am not especially confident about this outcome.

I’m not going to attempt forecasting next weekend yet as it is very much in the balance!…

Thursday 30th April 2020 – Mini Update

Sunshine and showers today – lots of showers, often heavy or perhaps very heavy, very possibly some thunder mixed in. Smaller chance of hail.

Around 13’C. Showers have already got going and are now pushing inland so expect some this morning, with the most frequent and heaviest between 11am and 4pm. Sunshine will be limited, but there will be a bit, mostly early morning and late afternoon/evening.

Full update tonight, though in brief, Friday showers though less showers, Saturday and Sunday quite cloudy but some sunshine and a bit warmer.…

Monday 27th April 2020

Goodbye sunshine. Hello rain.

Thanks to TC for the photograph showing the portender of change.

A small chance of a shower this evening, rain will spread up from France by around midnight or a bit before. Showery at first, becoming more persistent and heavy as the night goes on. Around 8’C.

Tuesday starts with heavy rain, perhaps very heavy at times, though occasionally not so heavy too. The rain will become lighter during the afternoon and gradually more patchy. 10’C at a push…yeah. Mostly cloudy overnight, still the odd splash of light rain possible, but mostly dry. 5’C.

By Wednesday, the doors have temporarily opened for the Atlantic to send low pressure systems our way.

Starting with some bright spells, a band of rain will cross roughly 11am to 4pm, give or take, some heavy bursts mixed in. Some sunny spells will follow, though another band of rain will cross late evening and overnight – clearing by dawn. 13’C by day, 6’C by night and a bit windy too.

Thursday starts sunny. An area of of showers associated with the centre of the low pressure will cross – plenty of showers, some heavy, perhaps with hail and thunder – or instead they may merge into longer spells of rain. 13’C at best and quite windy. Clear spells overnight, down to around 3’C.

Friday sees more showers, though less than Thursday. Plenty of cloud, some sunny spells – an improvement of sorts for sure. 15’C at a push. Variable cloud overnight, down to around 7’C.

The most likely outcome for Saturday sees some sunny spells and a scattering of heavy showers – though how much of a scattering is uncertain at this stage. It should be a tad warmer, maybe 17’C or so.

Confidence then breaks down – it looks like the first Spanish Plume event of the year will then happen, bringing heat and humidity from Africa across western and/or central Europe. So we may find some notable warmth and humidity for 12-48 hours, starting Sunday, Monday or Tuesday – quickly followed by heavy and possibly thundery rain.

So much uncertainty on this right now, it could all be further east than here and be a non-event for the UK, it could start anywhere between Sunday and Tuesday, could last anywhere between 12-48 hours – though it almost certainly will be followed by heavy, possibly thundery rain.

Thursday 23rd April 2020

Mostly fine and fairly warm for a few more days but something cooler and showery from next week.

Thanks to Eloise for the photograph…had a few good ones to choose from this week.

Tonight will be fairly clear, a bit of cloud around, mostly high cloud. 6’C.

Friday still sees high pressure vaguely in control, but fading as a presence and a little low pressure system to the west of Iceland starts to meander towards us.

Long spells of sunshine all day, with a bit of fair weather cloud bubbling up later in the afternoon. Warm, 22’C should just about be reached. Some cloud, some clear spells overnight, down to around 9’C.

Saturday sees a bit more cloud around, though still bright with it – and more sunny spells than cloudy spells overall. Temperatures a shade down, 19’C. Mostly clear overnight, down to around 6’C.

Sunday sees a mixture of sunny spells and cloudy spells. Perhaps more cloudy early-mid afternoon than at other times, but still bright when cloudier. Fairly warm, we might squeeze 20’C again. Just a very small chance of an isolated shower in the afternoon. The mixture of clear spells and cloudy spells continues overnight, 8’C or so.

By Monday we see low pressure developing to our north-east.

Still sunny spells, though again more cloud around and likely more generally hazy during the afternoon. A few scattered showers around and perhaps some general rain in the evening or early part of the night though that is uncertain. Reaching 17’C, perhaps a tad more.

Tuesday is a bit uncertain. Most likely somewhat cooler, say 13’C to 15’C and a fair chance of showers.

Day to day details are sketchy from here but the pattern is fairly likely, and that is one to a change back to unsettled conditions with low pressure systems moving west to east. Well, we’ve had a good run!

So Wednesday onwards, bands of rain interspersed with heavy showers. Windy at times too and temperatures back down to normal for the time of year, somewhere between 12’C and 15’C.

Not every day unsettled, the odd fine day, and it doesn’t look like it will be a long-standing pattern, a week or two of unsettled weather followed by high pressure building. Too early to be certain, but I’d suggest after a week of unsettled conditions, we’d get into a pattern of 1-2 fine days, 2-3 unsettled days, before we go full-time settled, warm and sunny once more for most of the rest of May and much of June.

Hope you are staying sane.…

Monday 20th April 2020

A fine week ahead and it will gradually warm up. Something different for you next week…probably.

No photograph. Don’t blame me!

Tonight sees mostly clear skies, down to around 8’C though that chilly easterly wind persisting.

Tuesday will see long spells of sunshine. The easterly wind persists once more taking the edge off, but we should reach 17’C. A little bit of high cloud at times. Clear overnight, down to around 9’C.

Wednesday sees long spells of sunshine again. The breeze lighter and temperatures up to around 19’C, maybe 20’C. Clear overnight, down to around 6’C.

Thursday sees long spells of sunshine again. I should really just copy and paste the above. Warm, 22’C, maybe a bit more. Clear overnight, down to around 6’C – maybe a bit of high cloud around.

Friday sees a bit more cloud around, mostly high cloud so we’ll still have a fine day with sunny spells – just hazy sunshine. Warm, 20’C – maybe a bit more. Variable cloud overnight, 8’C.

For Saturday we are in this zone of nothingness – a Col to go by the official name.

Neither high or low pressure close by, sunny spells, some cloud will bubble up with a smallish chance of catching a shower. Around 18’C. Variable cloud overnight, down to around 6’C.

Not especially confident yet for Sunday, but the most likely outcome is for more cloud than sun, and some showers around – a small chance of more general rain. Around 16’C but could easily be a few degrees either side.

Next week is still in the balance. Probably going to be cooler. Probably going to see some more rain/showers.

The general picture likely sees high pressure to our north and low pressure to our south, the uncertainly is mainly over position and strength of low pressure – we could end up with a rather cool and showery week, or we could end up with a rather cloudy and cool week. Broad trend – some differences.

I did mark out end of April and beginning of May in my seasonal forecast as potentially unsettled, and I’m still sticking with that.

I’m also still sticking with a plenty of sunny warm/hot weather for the rest of May and much of June.…

Saturday 18th April 2020

Quite a nice shape to this system has developed overnight.

Some heavy showery rain for the first part of the morning, this will clear north, but remaining cloudy and dull for most of the day – the odd bit of light rain might get squeezed out.

We should see a bit of sunshine by the evening, or late afternoon at a push. 14’C or so. Some cloud around overnight, down to around 5’C.

Sunday sees more sunshine though there will be areas of cloud floating around, perhaps more likely early afternoon for cloudier skies. 17’C, feeling warmer with just a tiny chance of an afternoon shower.

A reasonably fine week ahead, a cool and stiff breeze for Monday/Tuesday, warmer after that. And plenty of sunshine.…

Thursday 16th April 2020

Showery rain spreading up from the south for the next couple of days but plenty of fine weather to follow.

Thanks to Kathryn for the photograph.

We start the forecast with high pressure centred to the north-west of the UK though stretching across the UK – and low pressure edging closer to the south-west of the UK.

Clear spells at first tonight but cloud gradually thickening – one or two scattered showers overnight, but the bulk of the rain staying to the south of the UK. Down to around 8’C.

Friday will be a rather cloudy day, though perhaps some brightness both first thing and late. Showery rain will spread up from the south – some heavy bursts, possibly a rumble of thunder too. No specific guidance on timing, but could be a significant portion of the day. 15’C…maybe at a push.

Further heavy showers look like spreading up for the evening, probably late evening which could be very heavy and thundery. Clearing north as the night goes on, down to around 8’C.

Saturday starts cloudy – still possibly some heavy rain to clear if you are aware early enough. Sunny skies will spread up from the south late in the day, circa late afternoon, with a small chance of a heavy shower. Around 17’C once the sun comes out. Variable cloud overnight, down to around 7’C.

Sunday looks fair with some sunny spells. There will be cloud around at times, more likely early morning and mid-late afternoon onwards – but generally fair and we might squeeze 20’C again. Rather cloudy overnight with an easterly wind picking up – 8’C or so.

Monday looks rather cloudy but there should be some hazy sunshine. A weather front will be to our south/west and should stay there, though there is a small risk of it bringing a bit of rain – at the moment I think just a small chance. 15’C in a notable easterly wind. Fairly cloudy overnight, 9’C or so.

By Tuesday, low pressure is well to our south and high pressure is building to our north-east.

Tuesday looks a windy day with a cool easterly but otherwise lots of sunshine. Around 14’C but the wind making it feel lower. Mostly clear overnight, down to around 8’C.

Wednesday looks sunny. The breeze less notable, but still taking the edge off, say 17’C. Clear spells overnight, down to around 6’C.

Thursday sees long spells of sunshine in light winds, perhaps getting to 20’C once more, or close to. Clear overnight, down to around 5’C.

Friday is getting towards uncertainty zone, but the more likely outcome is for more sunshine, and temperatures close to 20’C. However, there is a smallish chance of something cooler and more showery instead…the less likely outcome but could happen.

Next weekend is uncertain, though the more likely outcome sees somewhat lower temperatures – possibly rather cool, possible rather average, with a chance of showers but overall reasonably fair.

High pressure likely remains in control for much of the coming weeks – often warm and sunny, but occasional outbreaks of showers.…

Monday 13th April 2020

A dry and sunny start to the week – it will become warmer but the shower/rain risk increases towards the end of the week.

Thanks to Tom for the photograph of distant thundery showers from Sunday – I had one in Harrow so I was happy!

I hope that you are settling into the new website if you are using it – it does allow me to use more images, like this chart showing high pressure over UK as we start the week – with low pressure to our south centred just off Portugal:

Tonight will be a chilly night, down to around 1’C – a touch of frost possible, more likely in rural areas.

Tuesday starts with some cloud around, but this will clear east as the morning goes on to leave good spells of sunshine during the afternoon. Lighter breeze and temperatures recovering to 13’C, perhaps 14’C. Variable cloud overnight, down to around 2’C – a chance of a frost in the most rural spots.

Wednesday sees long spells of sunshine. A bit of high cloud in the afternoon, otherwise glorious sunshine. Becoming quite warm once more, 16’C, maybe 17’C. Mostly clear overnight, chilly, down to around 3’C.

By Thursday, high pressure will be drifting north of the UK, allowing low pressure to the south to edge a bit closer. Long spells of sunshine once more, though increasingly hazy during the afternoon, with a small chance of a shower late in the day. Warm, 20’C or just below. Quite a bit of cloud overnight, some clear spells, a small chance of a spot of rain too, around 9’C.

For Friday you can see high pressure to the north of the UK, low pressure to the south/south-west.

It’s a bit of a close call at the moment as to the weather for Friday, and will depend on how close the low pressure system gets to the south of the UK.

The more likely outcome is that a band of rain will develop and spread north – will it reach us? More likely than not at this stage. When and for how long are still very uncertain – it could even arrive Thursday night, it might not arrive until Friday night. There would likely be some heavy rain mixed in too, but before it arrives, depending on timing, there could be some warm, bright weather too.

Details sketchy for Saturday. Likely fairly cloudy, perhaps still some showery rain around. Some bright spells also possible. Around 13’C give or take a couple.

More in the way of sunny spells for Sunday, probably nothing amazing but fine enough. Around 16’C.

This kind of pattern looks to repeat itself for the week after. High pressure over the north of the UK or to the north of the UK, allowing for often warmish/warm sunshine. Low pressure to the south – occasionally bringing rain or showers to us in the south of the UK – Monday looking a reasonably good candidate at this stage, though no certainty this far out.

I stress that it should be warmish and sunny more days than not.…

Seasonal Forecast – Spring 2020

[Note that this is not a new forecast – this was issued at beginning of March. I just wanted to ensure that it displays on the site, and have also had a couple of requests to do so!]

Welcome to my Spring 2020 Weather Forecast.

I’ll start with a word of caution. I remind you that I am not a professional meteorologist (I’m a software engineer in case you wonder!) and seasonal forecasting is experimental.

For winter, I went for a mostly mild and unsettled winter, alas I predicted a dry February – and it has been the absolute opposite. At least I suggested wintry showers to end.

So some of this forecast will be wrong. Hopefully I’ll get far more right than wrong.

Also I request that you put a bit of work in now – just a share, retweet, whatever you fancy to say thank you for the work I put in. I don’t ask for much!

And thanks to Rachel for the spring-like photograph.

There are less background signals available for spring forecasting – well, they are available but they have less impact.

Most notably is the still very strong polar vortex, which will help to promote a westerly-based flow, at least for the first part of spring.

At some point during spring this will recede, and after winters with an undisturbed polar vortex (ie no major sudden stratospheric warming events) there is a higher chance of a more notable final warming event of the stratosphere.

A notable final stratospheric warming event would likely mean a notable cool, showery spell, potentially with Arctic air, for around 2-4 weeks, would be likely. Impossible to be sure, but I’m factoring this chance in.

I do also wonder if a notable final warming event subsequently leads to greater oscillation of the jetstream, therefore allowing for more extreme temperatures to follow…a theory I have but not seen any research to back up or dispute this.

Otherwise, El Niño is neutral so no effect, and I’m not sure there is much else in the way of other background signals that will have an impact.

I do expect our summer friend, and snow-lovers enemy, the Euro high, to often be present to our south/south-east – which is pretty much the ideal position for high pressure if you like warmth.

March starts with a southerly-tracking jetstream and fairly mixed conditions. Some showers or rain at times, and with colder air in the mix, some sleet or even snow could be mixed in – though more dry days than of late.

High pressure will be starting to have more influence, and by the middle of the month will be reasonable dominant – yet varying in position so there will be a mix of mild days and chilly days depending on wind direction, some showers and still possibly wintry showers. We could easily see days with maximum temperatures of 7’C and 17’C fairly close by. Also some frost and overnight fog.

For the latter third of March, it should be mostly dry, and high pressure should be in a favourable position for some warm sunshine most days. I’m fairly hopeful that we’ll reach 20’C before month end.

Overall I expect somewhat below average rainfall, somewhat above average rainfall and temperatures to balance out slightly above average – though with quite a wide range of temperatures through the month.

Confidence level 65%.

April looks like starting warm, sunny and dry – with high pressure either over the UK or a bit to our south-east.

The second half of April probably a bit more mixed, with some showers and perhaps a bit of cooler weather mixed in – but still quite often on the warm and sunny side.

There is a risk of a strong final warming of the stratosphere bringing something more notably colder and unsettled towards the end of April.

Overall I expect below average rainfall, above average sunshine and above average temperatures.

Around 70% confidence.

May looks more mixed to start, perhaps arguably the more unsettled part of spring – with the aforementioned risk of a strong final warming of the stratosphere bring a higher than normal chance of northerlies…but timing of this is a total guess.

Again towards the end of the month, I expect our Euro high friend to promote much warmer conditions, perhaps quite hot – though with a chance of some downpours or thunderstorms developing.

Overall I expect slightly above average rainfall (though dependant on catching some downpours…there could be wide local variations), around average sunshine and temperatures averaging out above average – but like March, quite a range of temperatures.

Around 60% confidence.

So, not bad at all – if I, and the long-range models that I trust are correct.

A look ahead to summer?

Currently I’d suggest that summer, particularly June and July will see some hot or very hot conditions at times – but there are no signs yet of prolonged settled conditions.

Above average rainfall currently looks like the more likely outcome for summer as a whole, perhaps more widely unsettled for August but that is a very weak signal.

June and July currently look favourable for Spanish Plume events – 2-3 hot days, becoming very humid with thunderstorms breaking down – and repeat.

Europe could well see more heatwaves with some hot, dry conditions expected to dominate.

These are just early summer thoughts and my thoughts are bound to change at least somewhat.…

Sunday 12th April 2020

Today will be the last very warm day before things change.

Long spells of sunshine again, reaching 24’C, maybe 25’C. There will be some high cloud around, and there will also be some thundery showers breaking out this afternoon.

The risk seems greater over the Midlands, and this is how the ECM model handles it for 5pm, for example:

Despite the fact that the greater risk seems to be over the Midlands, I still think there is a 30% chance of a thundery shower for us, any time from 2pm – hail possible, heavy rain too.

Tonight sees cloud and cooler conditions move south, down to around 7’C.

Easter Monday will start cloudy, but the cloud will gradually shift back east to leave good spells of sunshine, in an easterly breeze – 12’C at a push.

Full update tomorrow evening.…