Thursday 30th September 2021

Well, it is definitely autumnal – and there is a wet and windy weekend to come.

Thanks to Paul for the photograph.

Tonight will be cloudy with occasional bits of rain – mild and windy at around 15’C.

Friday sees low pressure in charge to our north.

It will start cloudy with bits and pieces of light rain, followed by around 2 hours of heavier rain shortly after dawn, say 8am onwards approximately. Sunny spells will follow, the odd scattered shower at first but becoming mostly sunny for much of the afternoon. 16’C and winds lessening. Clear skies at first overnight, down to around 8’C, but cloud thickening as the night goes on.

You may remember me talking about the secondary low expected for either Saturday or Sunday – a low that develops south of the main low pressure system, and deepening rapidly.

This will arrive on Saturday morning, bringing rain – often heavy, from around mid/late morning onwards. It looks like the core of the low will be a little further south-east of us, say over Kent where winds will be strong enough for some damage/disruption – though for us gusts of 40-45mph more likely the maximum, during the afternoon and evening.

The rain will clear around late afternoon/early evening. 13’C for most of the day though a tad milder in the evening. There is a chance of a further spell of rain moving up from the south-west overnight – this is uncertain, and may track further east – really kind of 50/50 scenario at the moment, maybe 40/60 in favour of staying dry.

Sunday looks kind of reasonable. Sunny spells, fair weather cloud, around a 40% chance of a shower or two – certainly an improvement from Saturday. Around 16’C and quite windy. Variable cloud overnight, down to around 10’C.

Monday will be similar to Sunday, though a greater chance of showers – say around a 70% chance of a couple of showers, probably on the heavy side too. Some sunny spells and temperatures around 16’C, breezy. Heavy rain and strong winds likely overnight from another secondary low.

Tuesday sees this secondary low over us or close by – somewhere between north France and north England will likely see gales or severe gales depending on the exact track, but that won’t be known until closer to the time.

Also, Hurricane Sam to the east of America will be determining our weather for later in the week – more on that later.

Tuesday will be unsettled with either heavy rain or heavy showers – depending on the track/timing of this secondary low. Around 14’C.

What happens then depends on Hurricane Sam and how he/she interacts with the jetstream.

The slightly more likely outcome is that it interacts with the jetstream and pushes it north of us, allowing high pressure to build with some lovely October tropical air for us – and hopefully some warm sunshine.

The slightly less likely outcome is that it has minimal or no interaction with the jetstream, temperatures remain a little low and our weather is changeable – some sunshine, but also some bands of rain – less than the current pattern though.

Details for Wednesday onwards are therefore uncertain, though in either scenario some rain/showers looks likely at some point on Wednesday and/or Thursday – though in the warmer scenario you’d be noticing the warmth by Thursday.…

Monday 27th September 2021

Autumn has returned and it is an unsettled week or so to come.

Thanks to Tracy for the photograph.

Tonight sees clear skies and will be breezy, down to around 9’C. Cloud thickening by dawn.

Tuesday sees a large low pressure trough from roughly Greenland to the UK, with the main low over Iceland and a secondary low forming over us.

It starts bright with some sunny spells, but cloud will bubble up and heavy showers will spread inland – likely all seeing a few heavy showers, a small chance of thunder. By late afternoon/early evening, a band of heavy/very heavy rain will spread across from the west, lasting around 2 hours, perhaps longer – a bit of uncertainty on how quick it clears. Reaching around 17’C and breezy. Reasonably clear skies overnight, a very small chance of a shower, down to around 8’C.

Wednesday will be fine with good sunny spells, but feeling cooler in a north-westerly breeze at around 15’C. Some cloud around, notably late morning to mid-afternoon, and a small chance of a shower. Clear skies for much of the night, though cloud thickening before dawn, perhaps a light shower by dawn, 8’C.

Thursday sees the next weather front spreading down from the north-west but a weaker affair this one. Bright to start, some hazy sunshine but plenty of cloud and maybe a light shower. Generally fairly cloudy in the afternoon, some bits of rain at times, a little brightness, becoming windy and a bit milder, 16’C or so. Cloudy overnight with occasional bits of rain, mild and windy too, 15’C.

Friday is a tad uncertain on details, but broadly sees heavy showers and/or heavy rain moving east – but timing is uncertain with some sunny spells possible. Windy and around 16’C – showers less likely later in the afternoon. Clear spells overnight, down to around 7’C.

Same kind of pattern into the weekend – the main low pressure system to our north with a developing secondary low probably heading our way – these secondary lows can be quite nasty if you catch them in their peak development phase so there is a small-moderate chance of some very strong winds – but not possible to determine until closer to the time.

The whole development of this probable second low is uncertain (timing, track and whether it even develops at all), so it is possible that it arrives during the day and brings a wet and windy day for Saturday – but more likely it doesn’t and it will be quite reasonable, with decent sunny spells and just a small chance of an afternoon shower. Quite windy, around 15’C.

Assuming this secondary low develops as per more likely outcome, then overnight will see heavy rain and strong winds.

That would leave Sunday windy with sunny spells and scattered showers – likely on the cool side too, say 13’C very approximately.

Again, I stress the uncertainty over details – this possibly nasty low could be Saturday day, is more likely Saturday night, but could even be Sunday instead. It should track over England, but it isn’t impossible that it would be further south over France and we’ll miss the heavy rain/strong winds. There is a small chance of gales or even severe gales.

Next week likely starts windy and showery, perhaps with another area of rain.

Tentative suggestions that high pressure may build from Wednesday to re-assert more dry, sunny weather – we may even see more relative warmth at some point.…

Thursday 23rd September 2021

Well, it has been a pretty nice, sunny and warm September so far, and we can just about squeeze enough out for the weekend too.

A change to something more autumnal will occur on Monday – though changeable rather than outright unsettled.

Thanks to Claire for the photograph.

Tonight will see mostly clear skies, a small chance of some mist/fog by dawn in a few spots, down to around 11’C.

Friday sees high pressure remain in charge, though low pressure is not too far to our north.

Long spells of sunshine in the morning, some cloud will spread from the west during the afternoon but it will remain pleasant. Very warm, 24’C. Clear spells at first overnight but low cloud and possibly fog forming widely by the early hours, around 14’C.

Saturday starts dull and cloudy, perhaps foggy. This will take a while to break up and likely there will be spells of cloud for much of the day – but some sunny spells at times. A small chance of a shower, around 21’C. Clear spells at times overnight, though a small disturbance in the early hours may bring a shower or two – very hit and miss. Around 13’C.

Sunday is the last of the warm days. Sunny spells with variable amounts of cloud – a few scattered showers too, more likely during the morning and lunchtime period. Around 21’C. Cloud increasing overnight with rain by the early hours, some heavy bursts possible. A warmish and windyish night, 16’C.

Monday sees fresher air having spread across from the west.

The band of rain should have cleared by dawn, or will do a little after. Sunny spells and scattered showers will follow, around 18’C and breezy. Clear spells overnight, down to around 11’C.

Tuesday looks like sunny spells and showers. Perhaps a more organised band of heavy showers with hail/thunder possible – though details uncertain at this stage. Around 16’C. Clear skies overnight and chilly, down to around 7’C.

Wednesday is uncertain. The more likely outcome sees a spell of rain, the less likely outcome keeps it sunny all day. Around 15’C either way.

Thursday probably sees rain spread down from the north-west – uncertain on the timing so there could be sunny spells before and/or after. Temperatures somewhere between 12’C and 18’C depending on the timing.

Friday and into next weekend are uncertain on details, but looks like low pressure will be in charge, crossing to our north, but high pressure close to the south will have influence also.

Expect it to be windy but fairly warm, with at least one spell of rain in this period, and possible showers too – but also some bright spells too. Perhaps more likely back into the cooler air for Sunday.

Fairly low confidence – neither a washout or a warm, sunny weekend can be ruled out.

I do expect further warmer than normal weather after this short changeable spell – or as part of it, so October probably will end up warmer than normal too, and should settle down after this short changeable spell.

Looking further ahead, and my confidence for a colder than normal November and December is growing, the polar vortex is not forming in any meaningful way – similar to last winter – which will give higher chances of cold weather than normal.

Further to that, background signals remain supportive of a cold end to autumn/start to winter – and longer range models are already signalling an early season sudden stratospheric warming event.

I’m not sure how accurate such modelling is this far out, I don’t recall seeing an SSW modelled this far away.

But if one happens then it could be a notably cold November/December. Maybe make sure you have some alternative heating sources with the gas prices as they are!…

Monday 20th September 2021

Autumnal weather has been postponed and we’ll stay reasonably pleasant and warm this week.

It did look like we were going to get a notable taste of autumn late this week, however an ex-tropical storm in the far west of the Atlantic is taking a more southerly track than expected, pushing high pressure further east – which means that the north-westerly flow I was expecting by the end of this week is kind of getting squashed away.

Twice this September, at short notice, ex-tropical systems have affected our weather for the better.

Thanks to Paul for the photograph.

Mostly clear skies tonight, a few patches of mist and fog will form by dawn, down to around 10’C.

Tuesday sees high pressure in charge.

Early mist/fog patches will lift to sunny spells and variable cloud. Likely more cloud than sunshine during the afternoon but remaining bright with some sunny spells. Around 20’C. Fairly clear skies overnight, a small chance of mist/fog patches forming, down to around 10’C.

Wednesday will see good spells of sunshine. Some cloud at times, notably early-mid afternoon, but mostly a fairly sunny day. Around 21’C. Variable cloud overnight, down to around 11’C with a north-westerly breeze picking up.

Thursday morning will be cloudy due to a weak weather front, perhaps a spot of light rain. Becoming sunnier during the afternoon. Warm, 22’C. Clear spells overnight, down to around 12’C though with fog forming in places before dawn.

Early fog patches will clear on Friday, with good sunny spells following. Perhaps clear skies all day – perhaps some fair weather cloud, but either way pleasant and warm, 23’C. Clear at first overnight but low cloud and/or fog forming quite widely, around 13’C.

Saturday starts with either fog or extensive low cloud. It will probably take a little while for it to clear, but the sun should break through for another pleasant day with sunny spells, though not yet certain. Assuming so, then reaching around 21’C. A chance of showers spreading up from the south overnight – though very early stages and very uncertain.

Sunday is more uncertain. Those possible overnight showers could be Sunday morning showers instead – once that clears then again we should see at least some sunny spells, and we will still be in the warm air. But details on that possible area of showers Saturday night/Sunday morning, and levels of sunshine/cloud after are still uncertain.

Early next week probably sees fresher air with some rain/showers push in from the west, but I’m not yet convinced – it is the more likely outcome.

I still see further warmth and sunshine likely around end of September and into the beginning stretch of October – maybe even into mid-October – though occasional rain too.…

Thursday 16th September 2021

The reasonable weather continues (for now), though some showers possible and some cooler nights.

Thanks to Tara for the photograph.

Tonight will be fairly clear, albeit with some high cloud, down to around 12’C.

Friday morning sees hazy sunshine. General cloud will bubble up from late morning, and for a while there will be more cloud than sunshine – but becoming sunnier again later in the afternoon. Still warm, 22’C. Quite cloudy overnight though some clear spells, down to around 13’C.

By Saturday, the general picture is of a somewhat more energised Atlantic trying to push weather fronts in from the west – but coming up against a big block of high pressure to our east, with some unusually cold weather for the time of year in Scandinavia/Russia.

It will be pleasant for us, some decent sunny spells though a fair amount of cloud too. A 20% chance of a shower, more likely in the afternoon, but also possible first thing. 23’C. Rather cloudy overnight, a little bit of rain at some point as a weak weather front tries to push east, 15’C.

Sunday is a tricky forecast, the aforementioned weak weather front will sporadically be moving east, but will also start to intensify. Getting the location of where it will be when it starts to intensify during the morning is tricking – but most likely we’ll see showers or showery rain slowly and erratically pushing east. Don’t be shocked if it stays dry, it will depend on how far east the weather front pushed overnight, but most likely it won’t. Temperatures somewhere between 16’C and 20’C. Uncertain overnight – it is feasible that the weather front could get stuck in place, and we end up wet, but more likely it will have pushed east and we’ll see clear spells and around 10’C.

Monday is also a bit tricky. Broadly speaking, some sunny spells and quite a lot of cloud. However it is feasible that the weather front is either still stuck over us, or heads back west over us – and brings some more showers/showery rain. Temperatures around 19’C. Clear spells overnight, down to around 8’C.

Tuesday is easier – sunny spells, fair weather cloud – likely more cloud than sunshine around the lunchtime hours, and around 18’C. Clear skies overnight, down to around 8’C.

Wednesday sees a weather front spread down from the north-west, but more likely it stays dry for much of the day, with spells of sunshine, albeit increasingly hazy. Around 20’C. Timing is uncertain on the weather front as it spreads down from the north-west, but more likely either evening or overnight – bringing a spell of rain and some strong winds. Down to around 10’C.

Thursday looks like autumn announces its arrival – with low pressure spreading down from the north-west with more seasonal temperatures.

Some sunny spells, but also some cloud with either scattered showers or a band of general rain – uncertain right now. Quite windy and around 16’C. Variable cloud overnight, around 9’C, a shower or two possible in the wind.

Friday will be broadly similar, showers or rain, windy, cool – though some sunny spells also possible. Around 15’C.

Next weekend is uncertain at this stage. Slightly more likely outcome is that we stay in this cooler, north-westerly slow, windy, some showers but some sunshine too – or something like that.

Further warm days remain likely for the end of September and into the start of October, often dry with sunshine – but also weather fronts bringing rain, wind and fresher weather occasionally.

As October progresses, I do expect more north-westerly flows, so expect more wind, showers and cooler than normal conditions at times.…

Monday 13th September 2021

A mixed week ahead – some sunshine at times, but some showers and rain too – especially tomorrow.

Tonight will be mostly cloudy, some showery rain after midnight but pretty hit and miss, some places getting some light rain, some places staying dry, some places may see a heavy shower or two. 15’C.

Tuesday morning sees heavy showery rain spreading up from the south – it will intensify in places so some may get some heavy downpours, but for others just some showery, heavy rain. Brighter in the afternoon, but still some heavy showers around. Reaching around 20’C. Mostly cloudy overnight, perhaps a spot of light rain by dawn, around 15’C.

By Wednesday, we see Tuesday’s little low pressure in the North Sea, with high pressure building from the south-west.

Cloudy to start, perhaps a spot of light rain, slowly during the day some sunny breaks appearing though probably not until mid/late afternoon when there will be more notable sunny spells. Around 20’C. Fairly clear overnight, some high cloud, around 13’C.

Thursday starts sunny. Cloud will bubble from late morning, overall a little more cloud than sunshine, but pleasant enough and warm, 22’C. Clear spells overnight, though some high cloud, around 13’C.

Friday starts bright with some sunny spells. A weather front will push in from the west bringing cloud and some showers – timing uncertain but more likely afternoon/evening – though perhaps not until overnight. Warm, 23’C (unless the showery rain arrives earlier). The weather front likely continues to slowly cross overnight bringing some showery rain, around 15’C.

Saturday should be fine with sunny spells, some fair weather cloud and around 21’C. However there is a little bit of uncertainty due to Friday’s weather front – there is maybe a 20% chance instead that it lingers and we get something showery and around 19’C.

Similar for Sunday, assuming that weather front cleared east overnight on Friday, then Sunday will also see sunny spells, variable amounts of cloud and temperatures around 21’C. But if Saturday was showery (the 20% chance) then Sunday probably will be too.

The more likely outcome for next week is that high pressure hangs on, bringing mostly dry weather – though the odd weak band of rain may well progress south-east once or twice next week. Otherwise, fairly warm, some sunshine and some cloud.…

Friday 10th September 2021

Mostly warm/very warm over the next week or so, but changeable too.

Forecast is a day later than normal as I didn’t forecast staying out for work drinks until that late. Oops.

Scattered showers will fade this evening, mostly cloudy overnight though a few clear spells, another warm night at around 16’C.

Saturday sees our low pressure trough easing away north-east with high pressure building behind.

Quite a lot of cloud during the day, especially in the morning, but some sunny spells at times. Around a 20% chance of a shower. Warm, 22’C. Quite cloudy overnight, down to around 13’C.

Sunday will be quite cloudy, more so in the afternoon this time, but again some sunny spells. Feeling a tad fresher, around 20’C. Some patchy rain possible in the evening/overnight – but some uncertainty on the track and development at this stage. Cloudy and around 14’C.

Again a bit of uncertainty for Monday, but broadly fairly cloudy, some occasional brightness/sunshine, some occasional bits of patchy rain. Around 19’C. Quite cloudy overnight, some patchy rain possible at times, around 14’C.

Again uncertainty for Tuesday, with a tricky series of low pressure troughs to our south making it a challenging forecast. The more likely outcome would see a fine day, small chance of a shower, sunny spells, around 21’C. There is a small chance of wet weather instead – though more likely that is to our east. Also a small chance of something very warm and humid instead.

The most likely outcome for Wednesday is warm with sunny spells and a small chance of a shower. Around 22’C.

Thursday I’m actually more confident on, and we’ll probably see a build of high pressure bringing good sunny spells. Temperatures a bit uncertain, anywhere from around 19’C to 25’C, though I slightly favour the higher end.

For Friday we should just about hang onto the warm sunshine, but Atlantic weather fronts should be pushing in from the west by this point – so maybe by afternoon/evening we’ll see some showery rain, but maybe not until overnight. Temperatures somewhere around 22’C, give or take.

Interestingly there is likely to be some notably cold weather heading south into Russia next weekend and a strong block of high pressure should form to our east, somewhere roughly over Scandinavia.

The positioning of this will be key for our weather next weekend and into the following week. If it is around our latitude, then low pressure systems will struggle to gain a foothold – we should get some weak weather fronts crossing at times in this case, but the emphasis on dry weather.

Should it build further north instead, then we’ll likely get 7-10 days of unsettled conditions, starting next weekend.

Lots of uncertainty both short-term, and medium-term.

Enjoy your weekend.…

Monday 6th September 2021

OMG. It’s sunny. It’s hot. And you have another two days of this to go.

Thanks to Tara for the photograph.

Clear skies overnight and a fairly warm night, down to around 16’C. One or two patches of mist or fog by dawn.

Any mist/fog patches will quickly clear on Tuesday to leave glorious sunshine all day. Did I mention that I’ve got the day off? Hot, 28’C, maybe 29’C. Clear skies overnight and a warm night, eventually down to 17’C.

Wednesday sees low pressure approach though we’ll have some more hot sunshine first.

Glorious sunshine in the morning and a fair portion of the afternoon, cloud bubbling up from around mid-afternoon. 28’C should be achievable, though dependent on when cloud starts to arrive. A band of showers will cross at some point during the evening, perhaps heavy and thundery though uncertain at this stage. Another warm night, around 18’C.

Thursday sees a slack area of low pressure in charge. Basically sunshine and showers, though likely more cloud than sunshine overall, especially in the morning. Showers possible at any point, no guarantee of catching one but most likely you’ll get a few – they could be heavy/very heavy with a small chance of thunder. Still a warm feel, 22’C. Mostly cloudy overnight, one or two scattered showers and still on the warm side – no lower than 17’C.

Friday will be very similar, overall more cloud than sun but there will be sunny spells, especially in the afternoon. Some showers breaking out, they could be heavy. Still on the warm side, 22’C. Fairly cloudy overnight, down to around 15’C.

By Saturday, high pressure looks like it will be building in from the west – as we’ve seen recently it isn’t the sunniest or warmest position for it to be. That said, it looks reasonable, more cloud than sunshine overall, more cloud in the morning, more sunshine in the afternoon and a small chance of a light shower. Around 21’C. Variable cloud overnight, down to around 13’C.

Sunday will see high pressure in charge, but a northerly breeze may cool it down. Uncertainty on cloud amounts but more likely more cloud than sunshine, but still some reasonable sunny spells. Likewise on temperatures, somewhere closer to 18’C looks more likely, but it could be a few degrees either way.

Next week should start with high pressure in control, though positioning to be determined and it is really too early to have any thoughts on cloud amounts and temperatures. But settled is the theme.

Low confidence for the rest of next week due to the uncertain of Hurricane Larry’s track and the effects that might have on the jetstream for next week – slightly more likely that high pressure hangs on for a couple more days, perhaps becoming very warm/quite hot, with something more changeable from around the weekend. But could easily go unsettled instead.

Overall the second half of September looks like being warmer than normal, some wind/rain/showers at times after mid-month, and hints for drier conditions towards the end of September once more – potentially a pleasant finish and start to October.

I do wonder if September’s average temperature might be warmer than August’s?…

Thursday 2nd September 2021

Me again. Fancy a taste of summer?

There’s been a pretty sudden change in modelling this week, caused mostly by Hurricane Ida.

When I wrote on Monday, I was expecting a low pressure trough to cross England Sunday/Monday, however the remnants of Hurricane Ida to the north-east of USA are going to affect the jetstream sufficiently so that the aforementioned low pressure trough gets cut off to our west – which then pumps up hot air from the south.

I often say that the tracks of hurricanes can affect our expected weather patterns, and this is a good example. And a beneficial example if you want some hot sunshine.

Thanks to Chris for the photograph…from a few weeks ago.

Tonight will be rather cloudy, though some clear spells at times. Down to around 13’C.

Friday will be rather cloudy, more so in the morning and around lunchtime, but there will be more sunny spells than of late – some in the morning, more as the afternoon goes on. 22’C – and yes, we’ve finally lost the north-easterly breeze. Some clear spells, some cloudy spells overnight, down to around 13’C.

Saturday morning will be mostly cloudy. As the afternoon goes on there will be some sunny spells, likely ending mostly sunny. Around 21’C. Variable cloud overnight, around 14’C.

By Sunday we have high pressure to out east, low pressure to our west, and we start to see the much warmer air drift up from the south.

There will be cloud, overall probably more cloud than sunshine, but there will be sunny spells – particularly as the afternoon goes on. It will feel warmer, around 23’C, but if sunshine amounts surprise then maybe 25’C. A very small chance of an afternoon shower. Clear spells overnight, though low cloud and perhaps fog forming by dawn in a few places, around 15’C.

Monday is a bit uncertain in terms of cloud amounts, more likely to be cloudy in the morning with that small chance of early fog. It should become more widely sunny from some point, say late morning onwards, though still some fair weather cloud around and reaching around 26’C.. There is a small-moderate chance that cloud hangs on until say mid-afternoon, which would mean temperatures closer to 23’C. Variable cloud overnight, down to around 16’C.

There is still some uncertainty on cloud amounts for Tuesday, possible rather cloudy at times, but the more likely outcome is that it will be mostly sunny. Assuming so, then a rather hot 28’C should be reached. I happen to have the day off work too! Yes, that is a co-incidence this time. Clear spells overnight, down to around 16’C.

Wednesday should still be hot and sunny, though the afore-mentioned low pressure trough will be edging closer.

Good spells of fairly hot sunshine are probable in the morning, possible in the afternoon – though some heavy, possibly thundery showers are likely either during the afternoon or evening – well, perhaps not until overnight. Reaching roughly around 27’C. Showers or thunderstorms possible overnight.

By Thursday uncertainty is quite high, as it will depend on positioning of the low pressure trough.

Likely the heat will have gone, but probable that it will still be warm or very warm. Broadly something like sunny spells and showers, though sunshine amounts and shower frequency/potency uncertain.

Very low confidence for next weekend, but the slightly more likely outcome is warmish and fair – some sunshine, some cloud, the odd shower.


Autumn 2021 Weather Forecast

Autumn is here and so is my Autumn 2021 Weather Forecast.

Seasonal forecasts are experimental and things go wrong. My summer forecast accuracy was mixed at best – so do take this as a guide more than an actual forecast. Hopefully more will be right than wrong.

Was more right than wrong for my summer forecast? Hmmm. In terms of weather patterns, for example high pressure being dominant in August, then I’m happy with it. Alas, I had assumed it would be a sunny high as most high pressure systems are in summer – we’ve been really unlucky with the wind direction and hence all the cloud. So, though I may have predicted high pressure to be dominant – I also predicted it would be mostly sunny too. Is that wrong? Half-right?

Same with June and July, though I again feel that the main patterns were reasonably accurate, I vastly underestimated rainfall in June – I totally didn’t expect weak low pressure after weak low pressure to trundle across and set up over south-east England. I don’t think anyone did.

So don’t take this forecast as gospel.

Please can you also share the forecast in some way. Invite friends on Facebook, retweet on Twitter, e-mail it to your boss. Whatever works. Or don’t share it, I’m not fussed.

Finally thanks to Eve for the photograph. Please get in touch so I can make the charity donation!

Background signals

La Niña. This is expected to develop again over autumn, which tends to promote unsettled conditions in September and settled conditions later in autumn.

Polar vortex. Every August the polar vortex starts to develop – a weaker vortex is more likely this autumn/winter, similar to last year, this increases the chance of “stuck” weather patterns, and reduces the chances of weeks of low pressure systems going west to east on a strong jetstream, like we can often have in autumn.

Hurricane season. This is a curveball rather than a signal, but I do expect a busy September for Atlantic hurricanes and they can significantly alter expected weather patterns. This does make September especially difficult to forecast.


September is a difficult month to predict. It starts dry, and likely becomes very warm/quite hot, though after a couple of hot days thundery downpours may develop. After around 9th, things get tricky. A changeable two or so weeks is the more likely outcome, with some warm sunny days, some cooler cloudier days, some showery/wet days – probably warmer than normal.

However, if we strike it lucky with an Atlantic hurricane curving up and way north of the UK, it could reinforce the previous change to very warm/quite hot conditions – and we could end up with a mostly very warm and sunny middle of the month. This is an unknown curveball.

Towards the end of the month, a change to more settled conditions (assuming we had a changeable two weeks) is the more likely outcome, with temperatures around normal.

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

Confidence level of 40%. Which is unusually low.


There are fairly strong signals of high pressure being close to our east for the start of October, which should translate to warmer and sunnier than normal.

A change to more unsettled conditions is likely after the first 7-10 days, with spells of wind and rain, temperatures around normal.

Low confidence by the end of the month, I’d suggest broadly changeable, some wind and rain, some drier spells. A very slight signal for colder north-westerly/northerly flows being more likely.

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

60% confidence.


Again no real signal for the beginning of November, I’d assume fairly mixed, some rain but nothing too much, more dry conditions with variable amounts of cloud. Probably on the mild side.

There is a stronger signal from around mid-month, maybe a bit earlier, for high pressure to build to our west, allowing colder north-westerly or northerly flows, with some showers at times, and a mixture of sunny and cloudy spells otherwise.

Any showers more likely of rain down here, but wintry showers will be possible in any more potent northerly. Overnight frosts more likely too.

Overall I expect slightly above-average temperatures (though colder than average later in the month), around average sunshine amounts, somewhat below average rainfall.

Summary and Winter Thoughts

So, if I’m reasonably on target, we should have a warmer/milder autumn than normal though with the second half of November more likely to be colder than normal. A bit drier than normal overall, though some wet spells. Sunshine amounts around normal.

Background signals are mixed for winter – nothing new there. La Niña would tend to suggest a wetter winter, assuming it develops to be quite strong as expected (weaker La Niña’s are more supportive of cold weather) – yet there are plenty of background signals that suggest that cold spells are more likely than normal too. Kind of contradictory.

On balance, I’d say a colder than normal start to winter, ie late November and into December is more likely.

A mixed January.

A wet and windy February.

Winter always has the wild card of sudden stratospheric warming events, roughly every other winter. We had one last winter and it did bring some cold northerly weather at times, albeit minimal snow. Impossible to predict the chance of one occurring this far in advance.

That’ll do. I need some dinner.…