Friday 29th December 2023

Rain before the year ends, and rain to start the new year too.

A rare indulgence from myself for the photography this time, with a glimpse of the rare nacreous clouds that I had the excitement of seeing on Christmas Eve up north.

Tonight sees showers fading, reasonably clear skies for a time but cloud will gradually thicken with a little rain arriving before dawn. Down to around 5’C.

The general picture for Saturday sees the next low pressure system arriving.

It will be mostly cloudy, perhaps a little brightness at times. The main band of rain stays to our west, but there will be occasional bits of rain throughout the day, more so in the morning. Becoming windy but also milder, 11’C. The band of rain will get its act together in the evening and push east – a little uncertainty on timing but anywhere from 8/9pm onwards, give or take. It does look like there will be a squall line mixed in – 15 to 30 minutes of very heavy rain and gusty winds, perhaps causing some isolated damage, say 11pm/midnight – but timing a little vague. Further showery rain will follow the likely squall band. Dry and cooler later in the night, down to around 4’C.

New Year’s Eve starts dry, and likely sunny. Cloud soon develops and a fair scattering of showers will push across – most places catching a few showers, some heavy/very heavy and quite squally in gusty winds. 8’C. Some showers overnight, but they will tend to become fewer – some clear spells and down to around 4’C. Still quite windy.

New Year’s Day is uncertain at this stage – the next low pressure will be approaching but there is also likely a cut-off low ahead of it, where the models are struggling to handle the direction. It’s roughly 50/50 as to whether it heads to southern UK or northern France, maybe 60/40 in favour of the UK. If so, then, well, it will be wet. If not, then sunny. Around 7’C either way. The next area of rain will arrive either in the evening or overnight, and winds will become strong again too. Will I make it to 2024 without booking a holiday?

Low pressure will be in control for Tuesday.

Details uncertain at this stage, but likely to involve rain and/or showers at some point. Around 10’C, give or take and breezy.

Wednesday is more likely sunny spells and heavy showers – perhaps a spell of general showery rain. Around 10’C or so.

Thursday and Friday more likely sees low pressure still around, with showers or rain at times and temperatures more likely in the range of 8’C to 10’C.

Next weekend may become colder – there are certainly fairly strong signals for high pressure to form either over the UK or to the north/north-west/north-east – all of which are cold solutions. Though perhaps next weekend might be a little too soon, and it happens into the week after.

This probable cold spell (as much as any weather patterns against the norm can be probable 8-10 days away) is nothing to do with the possible sudden stratospheric warming (SSW) event, which the media now seem to have picked up on…and right on cue it now looks more like a minor warming event than a major one.

Whether a minor SSW, if this is what it will be (still 10ish days away from happening), will affect our weather later in January is debateable. But before then, we already have a weak tropospheric polar vortex, along with an easterly QBO, El Niño and now a possibly favourable phase of the MJO – all things I mentioned in my winter forecast – all things that increase the chance of cold spells in northern Europe in winter.

Interesting times ahead…but no guarantees of cold – remember, it goes against our normal weather patterns in autumn/winter, so it takes something notable to overcome the mild.

Have a fun weekend and enjoy your New Year’s Eve if you are celebrating. Thanks for reading during 2023.…

Tuesday 26th December 2023

One fine Boxing Day, but then the wind and rain is back – with the jetstream starting to track further south. More profound wintry changes down the line to come, perhaps.

Thanks to Jonathan for the photograph.

Boxing Day starts sunny. High cloud will build during the morning, and gradually this will thicken, making things hazy – but it remains bright and pleasant. Cooler than of late, 9’C. Some outbreaks of rain later this evening and overnight – though the more persistent and heavy rain will be further north – breezy too. Down to around 6’C for a time but becoming milder later in the night.

So the general picture for Wednesday sees low pressure arriving, on a more southerly track of the jetstream.

A cloudy start for Wednesday, some little bits of light rain but mostly dry. During the afternoon, showery rain spreads east – some heavy, and the winds become strong and gusty too once more. 12’C. Dry in the evening for a time, though a heavy shower or two passing through late evening – then likely dry overnight. Remaining windy and down to around 8’C.

Thursday remains windy. Some sunny spells at times, but also some heavy, squally kind of showers passing through – most places catching at least a couple but a small chance of missing them all. Around 11’C. Fairly clear skies overnight though tending to be more cloud later, down to around 6’C.

More in the way of cloud for Friday, though some sunny spells likely at times. Some showers likely, or perhaps showery rain but quite some uncertainty on this aspect, in terms of timing, intensity and frequency of showers. Around 8’C and still quite windy. Further showers possible overnight.

Saturday looks quite uncertain though the broad pattern is waiting for the next low pressure system to arrive – maybe it arrives in the afternoon bringing rain, maybe it arrives in the evening/overnight but there are showers beforehand.

New Year’s Eve looks windy, with rain clearing to showers – again the uncertainty on timing.

Into the start of 2024 and it looks like further low pressure systems will head our way, but tracking further south than usual due to the jetstream being further south than usual. This means colder air can filter down and perhaps there could be some sleet/snow mixed in (ie rain turning to sleet/snow, etc) – low chances but possible. Though also possible that they go further south of the UK, and we’ll be cold with overnight frosts instead.

Quite a lot of uncertainty for January, but higher chances of notably cold spells than normal – not only do we have a possible SSW event which could impact our weather later in the month, we also have a disrupted polar vortex and various other background signals, both short and long-term that favour colder weather. It’s a bit too far out still, but the second week of January certainty has possibilities in terms of cold conditions.

Enjoy your Boxing Day – next full forecast (with a bit more research!) should be on Thursday.…

Thursday 21st December 2023

It’s the last forecast before Christmas and it isn’t very interesting – broadly speaking, mild and windy with only bits of rain – becoming cooler and more unsettled after Christmas.

Thanks to Kate for the photograph.

So tonight will be cloudy and fairly windy, the odd splash of light rain at times. The rain a bit more persistent later in the night, but still light/moderate. Down to around 8’C.

The general set-up sees a large area of low pressure to our south-west – with the jetstream fairly strong to our north, and hence the windy and mild weather.

Friday starts cloudy – some bits of light rain but this will fade. Mostly it stays cloudy, and windy, but there may be a bit of brightness at times. Around 11’C. Cloudy and fairly windy overnight, perhaps a bit of drizzle, down to around 7’C.

Saturday will be cloudy and fairly windy, perhaps a bit of light rain or drizzle at times too. Around 11’C, maybe 12’C. Cloudy and windy overnight, a weak weather front will bring something in the way of showery rain from late evening onwards – mostly light/moderate so amounts minimal. Down to around 9’C.

Christmas Eve will be cloud and windy – some notably strong gusts at times. Some bits and pieces of mostly light rain around at times. Mild, 13’C. Cloudy with outbreaks of mostly light rain overnight, still windy but nothing to stop Santa, still around 12’C.

Christmas Day will see outbreaks of rain at some point – though some uncertainty on timing. It could be morning, it could be on and off all day, it could be evening, or it could be morning and evening. The rain generally light to moderate. Quite windy and still mild at around 13’C.

Uncertainty certainly increasing by Boxing Day, but the more likely outcome is for a bright, perhaps sunny day (remember that stuff?) but cooler, around 8’C. Some uncertainty as to when the next low pressure system arrives – perhaps later on Boxing Day, but more likely overnight or the day after.

Wednesday and Thursday, potentially wet and windy, but a lot of uncertainty as to the track of this low pressure and how it will develop in general. It could even be a named storm, with some disruption – so worth keeping an eye on if you have travel plans, as I do.

Most likely it stays unsettled over the New Year and into the start of 2024. Temperatures generally around average, but some colder weather possible. Cold enough for snow is unlikely, but cannot be totally ruled out.

Looking further ahead, there are rumblings of a possible sudden stratospheric warming event for the beginning of January – and such events significantly increase the chance of (but far from promise) notable cold spells 2-4 weeks following, such as the Beast From The East event in 2018, which was a fairly perfect response.

It’s a long way from being an event in the stratosphere, let alone having any impacts on the troposphere, where we live. If, and it is a big if, it is going to have wintry consequences for us, then this would be mid-late January onwards, give or take.

That’s not to say that cold spells cannot happen before then, or if the SSW doesn’t occur – certainly short cold spells could happen in the first half of January, but the main theme for the first half of January looks like rain and wind.

That’ll do you.

I wish you all a very merry Christmas, and if you don’t celebrate Christmas, then enjoy the extra time off work. And if you don’t celebrate Christmas and have to work bank holidays then maybe, erm, enjoy the wind.

I don’t know when the next forecast will be but I’ll find time at some point, even if for a short update.…

Monday 18th December 2023

Nothing very interesting ahead, a lot of cloud, some bits of sunshine, a little rain and quite a bit of wind. Maybe colder for Christmas Day…maybe.

Thanks to Louise for the photograph.

Tonight will be cloudy with some showery rain developing from around midnight onwards. Mild and breezy, 11’C.

The general picture for Tuesday is that our high pressure that has kept us dry and increasingly mild the last few days has moved west, allowing wind and rain to our north to encroach at times – but not take over.

Tuesday starts cloudy with outbreaks of rain, quite heavy for a time. This starts to ease around late morning, and it will become dry and eventually there will be some sunshine by mid/late-afternoon. Generally breezy – mild in the morning at around 12’C, though dropping a little when the rain clears. Fairly clear skies overnight, though too breezy for a frost – down to around 4’C.

Wednesday starts bright with some hazy sunshine, though cloud will thicken and mostly it will be cloudy – some occasional brightness, but also perhaps a bit of light rain/drizzle at times. Fairly windy, around 10’C. Cloudy overnight, perhaps a spot of drizzle at times and around 10’C. Windy.

Thursday generally looks cloudy, some occasional bits of light rain/drizzle, and it will be windy – some fairly strong gusts at times. Maybe a little sunshine at times later in the afternoon. Mild, around 12’C. Rather cloudy overnight, some occasional bits of rain/drizzle, windy and around 10’C.

Not much difference for Friday, still cloudy, still windy – a little less so than Thursday. Some bit of showery rain around and around 11’C. Cloudy, windy with bits and pieces of occasional rain overnight, around 9’C.

You can probably write this yourself by now, but Saturday will be – yep, cloudy, windy with bits and pieces of occasional light rain/drizzle. Around 11’C. Same story overnight.

Christmas Eve? More likely cloudy, windy with bits and pieces of showery rain at times. A tad milder, 13’C.

Too early for much confidence for Christmas Day but there’s at least a chance of something colder and sunnier spreading down from the north-west. Though the more likely option remains some continuation of mild, cloudy with some showery rain.

This possible 1-3 day colder spell could arrive Christmas Eve – low chance, Christmas Day or Boxing Day, though its not an especially high chance – and mild/wet should replace it fairly quickly.

Next forecast will be on Thursday, all being well.…

Thursday 14th December 2023

Mild and dry for a while…colder in time for Christmas? Maybe. And the wind is a feature too.

Thanks to Lene for the photograph…though not sure I can offer you much sunshine.

Tonight sees some cloud, and some clear spells – down to roughly around 3’C for most, but quite give and take as it will depend on how much in the way of clear spells – some spots perhaps just about getting a frost.

So the general picture sees a large area of high pressure to our south-west – starting to suck up much milder air but also a lot of cloud – and this high pressure in this kind of position until Monday.

Friday sees hazy sunshine for most of the day – sometimes the cloud perhaps thickening up to blot out the hazy sunshine, and becoming a little breezy later. Around 7’C, maybe 8’C – mild air not yet here. Fairly clear skies to start the night, though a layer of high cloud remains – cloud tending to thicken as the night goes on. Down to around 3’C, again pretty give or take depending on cloud amounts – so a small chance of a frost in some locations.

Saturday will be mostly cloudy – some occasional bits of sunshine, but mostly cloudy. Breezy and mild, around 11’C. Likely cloudy for most of the night, but some clear spells possible. Down to around 7’C and windy.

Sunday has more scope for sunshine though there will be cloudy periods, and when sunny, the sun may be hazy at times. Mild and quite windy, around 11’C. Plenty of cloud overnight, though some clear spells at times, more so earlier in the night. Down to around 6’C.

Monday looks cloudy once more – perhaps a spot of drizzle at times as a weak weather front edges closer. Still quite windy and around 12’C. The weak weather front continues to sink south overnight, more cloud and some light rain – perhaps something more persistent. Around 11’C.

Tuesday likely starts with outbreaks of rain – some uncertainty over this, and also when it will clear, but assuming it clears during daylight, then it will be followed by sunny spells and something cooler. Reaching around 12’C though temperatures dropping once the sunnier weather arrives. Still breezy. Fairly cloudy and fairly windy overnight, down to around 4’C.

By Wednesday our high pressure is now further west – and the flow gradually turns more north-westerly.

Details uncertain for Wednesday – likely windy, but otherwise sunshine/cloud amounts uncertain, there is a possibility of some showery rain. Around 9’C.

Likewise details uncertain for Thursday, Friday and into next weekend – but the north-westerly flow should bring some rain at some point, and will likely be windy, perhaps strong winds – with a chance of a notable storm system bringing disruption, say around a 25% chance. It definitely needs watching if you have travel plans later next week (as I do).

This may be followed by 1-2 days of colder weather, perhaps a wintry shower – though the form horse looks like a return of milder weather in time for Christmas Day.

A White Christmas isn’t impossible, but remains just a 5% chance.

Have a good weekend.…

Monday 11th December 2023

One more low pressure system before it settled down for a little while.

No photograph this week.

Clear skies at first tonight but a band of showers slowly crossing from around late evening onwards – potentially heavy/very heavy showers overnight. Down to around 4’C at first but becoming milder later.

General picture for Tuesday sees low pressure pretty much over the UK.

Some sunny spells, mostly in the morning, but a fair few heavy showers around – most places catching a few during the day. On the mild side, 11’C. Mostly cloudy with occasional showers in the evening and overnight, down to around 8’C. Becoming quite windy later in the night.

Wednesday starts cloudy, with bits and pieces of light/moderate showery rain. This gradually fading in the afternoon, perhaps a little sunshine to end. Feeling chilly in the wind, 8’C. Clear skies at first – down to around 1’C, cloud thickening as the night goes on and a weak weather front approaches.

Thursday starts cloudy, some bits and pieces of light rain/drizzle. Becoming sunny during the afternoon. Around 9’C. Reasonably clear skies overnight, though high cloud tending to increase later. Down to around 1’C – a frost possible, especially in more sheltered spots.

By Friday, high pressure nudges closer to the UK.

It looks like there will be quite a bit of cloud around on Friday, especially later in the day – more variable in the morning so some sunny spells. Around 8’C. Likely cloudy overnight, and assuming so then around 8’C.

Saturday looks cloudy but mild. Breezy too, around 11’C. Likely cloudy overnight, and assuming so then around 8’C.

Sunday is probably cloudy and mild too. Around 10’C.

The more likely outcome for next week is that high pressure moves back west into the Atlantic, and we end up more changeable – with wind and rain becoming more likely once more.

Something a bit colder is plausible for a day or two later next week, though generally the temperature theme is more likely average to mild, and that goes through until Christmas.

Chance of a White Christmas? Well, it isn’t impossible but I wouldn’t put it higher than 5% right now.

Better chances of something wintry after Christmas and into the New Year – though that’s a very long way away meteorologically.…

Friday 8th December 2023

Back to unsettled for a while, though probably dry by next weekend.

Thanks to Lucinda for the photograph.

Not too bad a day today for December, decent spells of sunshine, some cloud – more so in the afternoon and becoming breezy. 11’C – a small chance of a passing shower but more likely dry. Clear skies at first overnight but clouding over with showery rain spreading up from the south-west in the early hours. Down to around 6’C.

So the general picture for Saturday sees a large low pressure system far west over the Atlantic, a smaller one closer to the UK, being driven along on a powerful jetstream – powerful enough to push the high pressure block to the east away.

A wet morning, some heavy bursts mixed in, but dry by late morning, lunchtime at the latest. Sunny for the afternoon, a little cloud and an outside chance of a shower. More notable will be the wind – windy all day with some notably strong gusts – not far from gale force in the evening, so the odd bit of damage/disruption possible. Mild, 12’C. Mostly clear skies overnight, the wind slowly easing, down to around 5’C.

Sunday starts sunny, but it will quickly cloud over with around 3 or so hours of heavy rain over the lunchtime period, and then brighter skies to end the day. Breezy and fairly mild, around 11’C in the afternoon. Variable cloud overnight, a stray shower not impossible in the breeze, down to around 7’C.

A ridge of high pressure for Monday will lead to sunny spells and variable amounts of cloud during the day – around 11’C. Clear spells at first overnight though it looks like a band of heavy/very heavy showers will cross later in the night – some uncertainty on this development.

Low pressure over the country on Tuesday will mean heavy showers are likely – some sunny spells in between. Around 12’C. Showers possible overnight.

On Wednesday, low pressure should be over the south-east of the country – drawing in somewhat colder air from the north-east. Generally kind of cloudy, with some showery bits of rain – but fairly limited amounts. Around 7’C and feeling cooler.

By Thursday we should see the Azores high nudging in, so bringing something more settled – longer spells of dry weather. Uncertain on cloud/sunshine amounts at this stage – not impossible there is still a weak weather front to clear on Thursday still. Temperatures more likely around 8’C.

Friday and over the weekend are likely dry – uncertain on cloud/sunshine amounts at this stage. Fog and overnight frost possible, perhaps the former more so, though details will take a few more days to resolve.

Enjoy your weekend…I better do some work.…

Winter Weather Forecast 2023/24

Welcome to my weather forecast for winter 2023/24 for Reading & Berkshire, though it is broad scale enough to easily be applied to much of central/southern England.

Firstly the usual caveat – seasonal forecasting is experimental, and I actually seem to be getting worse at it! Some of this will be wrong – there is nobody who can accurately predict a month of weather repeatedly, certainly nobody can do three months. If this is all right, then it is at least partly down to luck.

But, we can still have a reasonable idea about the more likely outcomes, given background signals, especially in winter where background signals are always much stronger and more effectual on our weather.

That said, events happen that shape the weather outside of the background signals – and this is where long-range forecasts tend to go wrong.

Also thanks to Louise for the photograph. Yes, I am braving a snow photograph – though how could I resist the accomplices?

Background Signals

El Niño tends to mean milder and wetter conditions earlier in the winter, drier and colder later in the winter.

We are in the easterly phase of the Quasi-Biennial Oscillation (QBO), which tends to mean the westerly flow is less strong – so high pressure and even easterly flows can be more likely (ie colder conditions).

The wild card in winter is always the chance of a sudden stratospheric warming (SSW) event – and these seem to be more common in winters that have the combination of El Niño and an easterly QBO. SSW events can lead to events like 2018’s Beast From The East – many significant winter events in years gone by had an SSW 2-4 weeks beforehand – but it never guarantees anything cold, just significantly increases the chances.

The sea surface temperatures in the Atlantic are in what is known as a tripole – warmer than normal to our north-west, cooler than normal to our west, warmer than normal to our south-west. This is thought to increase the chances of the jetstream tracking further south, and hence allowing colder air south – winters of 2009/10 and 2010/11 had such a pattern.

These are all in favour of cold weather during winter, or at least parts of winter.

However, we live in a warming climate – this year is likely the warmest on record so there is that to take into account.

And the Indian Ocean Dipole is in a strong positive phase, which a fair few years back was thought to be the main driver of our mild winter, when it looked like the background signals were pointing towards cold. So there is some conflict in background signals, as there normally is.

In the shorter term, the Madden-Julien Oscillation is pointing towards the chance of colder conditions towards the end of December.

December

After a cold and fairly dry start to the month, the Atlantic will take over and it will become unsettled, with rain and sometimes wind. Generally becoming milder, though the odd colder day possible. Around or just after mid-month, high pressure will likely try to establish itself, at least for a few days.

Before Christmas, more likely we revert back to something changeable, with some milder days with rain, some drier and cooler days, though less confidence on this period. Towards the end of the month (perhaps in time for Christmas but more likely after), increased chances of cold weather spreading down from a more northerly context – snow and ice become possible, though it may well be fairly marginal with the jetstream not likely to especially calm down.

Overall I expect above-average rainfall, slightly above-average temperatures, slightly below-average sunshine amounts.

Confidence level of 75%.

January

January does look like a particularly unsettled month – probably on the cold side to begin, with chances of snow, though again quite possibly marginal with mild weather trying to regain control.

It shouldn’t take too long for this to happen – and become generally mild with rain and wind, perhaps some named storms. It likely wouldn’t always be mild – some colder conditions will be plausible as low pressure systems clear with short spells of north-westerly or northerly winds, perhaps with wintry shower and overnight frosts. But generally the theme for January is unsettled and fairly mild.

Suggestions that towards the end of the month, high pressure over the continent may become more influential – so drier, perhaps cold and frosty – though less sure on this.

Overall I expect above-average rainfall, slightly above-average temperatures, slightly below-average sunshine amounts.

Confidence level of 65%.

February

The signs point towards an SSW being a bit more likely than normal this winter, so I’m tentatively suggesting February as a cold month, but I’m also assuming that both an SSW happens, and it is favourable for cold conditions in the UK.

Cold, with overnight frosts and snow showers at times, especially if we end up with an easterly flow, though often dry.

However, if an SSW does not happen, I still think a fairly dry and fairly cold month is the more likely outcomes, with overnight frosts and fog possible.

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

Confidence level of 40%.

In Summary…And Early Spring Thoughts

In summary, I’m expecting an unsettled and often mild December and January, though with some potential for cold and wintry spells. February has higher chances of cold and snow, though nothing is certain in long-range forecasting.

Early suggestions for spring, are of a colder than normal spring, at least to start.

Enjoy! And roll on spring warmth so I can get back into the sunshine.…

Tuesday 5th December 2023

The cold air relents and the Atlantic wins – expect more wind and rain, and it to gradually become milder. For a while.

Thanks to Clare for the photograph.

We start Tuesday with low pressure slowly easing away – struggling to move far into the continent due to the high pressure block to the east, with the next low pressure systems waiting to the west.

It starts cloudy and damp, with bits and pieces of mostly light rain/drizzle. This gradually fades during the day, and the cloud will break to allow a bit of sunshine at times this afternoon. Still fairly chilly at 6’C. Reasonably clear skies overnight, a few fog patches forming, and a frost for most – generally down to around -2’C, give or take.

Wednesday starts frosty for most, foggy for some – the fog becoming more extensive for a time before slowly fading away – most places should see some hazy sunshine in the afternoon. Reaching around 4’C, maybe 5’C – though if fog lingers into the afternoon (it should clear) then a little lower. Cloud gradually thickening overnight, with patchy rain from late evening onwards – and becoming quite windy. Around 5’C.

Thursday will be cloudy with patchy rain, until a more organised band of heavy rain crosses in the afternoon. Windy too, around 7’C. Variable cloud overnight, a stray shower possible – around 8’C.

Low pressure over England for Friday which will bring quite a lot of cloud and some showers – perhaps merging into longer spells of rain. Breezy but milder, 10’C. Fairly cloudy overnight, around 7’C.

Saturday sees the next weather front cross, bringing another spell of rain – possibly heavy though some uncertainty as to this aspect. Mild and breezy, 12’C.

Sunday, Monday and Tuesday all likely to see rain/showers at some point – though timing uncertain, hence me grouping them together! Generally mild and windy at times.

More likely staying fairly changeable until around Christmas, though short colder and drier spells should be mixed in – the general theme mostly should be often unsettled and fairly mild.

I will do the winter forecast when I get time…not sure when that will be! This week I hope.…

Winter Photograph Request

Gosh it’s winter (and I very much know going outside), so I need to do the winter weather forecast.

Usual rules:

  1. Must have weather. Must have winter weather of some description! I choose to fit the forecast.
  2. Must be the local area.
  3. Can be from any year, doesn’t need to be recent.
  4. Must be landscape-orientated, ie the width longer than the height. I know plenty of people ignore this, which is totally fine, crack on! But I only use landscape-orientated images.

I will donate £10 to the charity of the winner’s choice…I will be in touch with whoever I choose.

Whoever’s photograph I choose will adorn the forecast and also be the cover photograph on Facebook for the next 3 months.

Please add them to the Facebook post or e-mail them.

Not sure when I’ll get time to write the forecast as my life is still chaos, probably will be next week.…