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Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

Mentioned in a few other posts but I thought it might be worth a thread of its own.

It's very noticeable since around 2016 and more particularly 2020 how the character of February has markedly changed. It hasn't been an especially cold month for a while now (last notably cold one was 1991) but on the other hand we did see plenty of settled and anticyclonic Februaries from 1992 to 2015. Further back we had eight benign Februaries on the trot from 1981 to 1988.

Since 2016 to a degree and more particularly since 2020 it seems to have become a month in which the Atlantic swings into overdrive: exceeding October and even perhaps December for relentless Atlantic domination. 2020 was the most extreme example, basically stormy from start to finish with constant SW-lies and literally no break. 2022 was a variation on the theme with the jetstream somewhat further N (hence less wet) and did feature a fine few days near the end, while 2024 had equally frequent but less intense lows meaning it was almost was wet as 2020 but less windy.

Contrast that to preceding years, when very mild and wet Februaries were less frequent. There was 2014. Possibly 2011 but the EWP was significantly lower than 2020, 2022 or 2024. Before that 2007, 2002, 2000, 1997, 1995, 1990 and 1989 and then we have to go back to 1980 for the next mild and wet February (and even that had a dry second half).

There was perhaps a similar cluster from 1995-2002 but on the other hand we didn't get so many extreme 100mm+ months.

In contrast, earlier in the winter seems to be no more zonal than before and has even featured significant anticyclonic spells.

I wonder what is driving the emergence of February as possibly one of the three most reliably very wet, mild and Atlantic-driven months of the year (along with October and December)? We've had three 100mm+ EWP Februaries since 2020 and there is at least a chance of a fourth, on current model output.

I guess higher SSTs might play a part: historically this was a time of year when the SSTs started dropping towards their spring minimum, meaning less scope for monster lows to spin up. So effectively modern Feb SSTs are more like late autumn or early winter SSTs of old.

On the other hand, that would presumably mean Nov/Dec SSTs are even higher than before and would cause even more intense lows to spin up? But November in particular seems to have shown no significant increase in storminess: indeed we've had plenty of relatively benign Novembers in recent years.

Edited by Summer8906
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Posted
  • Location: Islington, C. London.
  • Location: Islington, C. London.
Posted

Well I've wondered if it's the gradual warming of the NH as the sun gains strength combined with the fact that most of the month is likely to be zonal by default, essentially squeezing the gradient to bring mild and stormy conditions due to an enlarged Azores and a strong PV.

It seems October was the first month to go, weirdly warming by 1C in the mid-20th century. We think of a 10C October as normal but historically that was actually mild before approx 1940. The 9s were average so to speak. Then March became ridiculously mild in the late '80s and through the '90s then February followed suit. You'll actually notice how many mild Februaries there were between 1988 and 2002, though punctuated with cold/average ones. The pace February has picked up since 2016 has been silly though. The 10 year average is tracking warmer than a normal March 50 years ago. Yet January remains static since 1988. Strange.

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Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 LetItSnow Interesting, though I would expect the effect of the sun gaining strength in late winter would be minimal over the oceans, indeed SSTs are lowest in March IIRC. Even in April, tropical maritime air would be relatively cool (only marginally above average by day) with most warm airmasses arising from a continental source (and explaining, perhaps, why low formation in spring is often over the European continent).

For that reason I'd expect the contrast between tropical maritime and polar maritime to be less in February than say December or even November, when SSTs at lower latitudes would be seriously warm but the polar night is already in place. So I'd expect, say, November, to be far more prone to huge lows as a result - yet Nov 2021 and 2024 were both mostly benign, Nov 2020 wasn't especially stormy (though dull and drizzly) and even Nov 2023 was less unsettled than most of the autumn and winter months last year.

Edited by Summer8906
Posted
  • Location: Islington, C. London.
  • Location: Islington, C. London.
Posted

 Summer8906 I'm thinking more of the impact on the stubborn heights over Europe which have become omnipresent, basically it fuelling that.

Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 LetItSnow Perhaps though if early-in-the-year warming is taking place, it might be more likely to happen over continental areas such as southern Europe, leading to higher temp contrast north-to-south over continental Europe in Feb compared to the pre-AGW era. That might, in theory, lead to more lows and frontal systems forming over continental Europe, meaning spring blocking patterns develop earlier?

Rarely seems to happen though, March isn't usually blocked, never mind February.

Edited by Summer8906
Posted
  • Location: Islington, C. London.
  • Location: Islington, C. London.
Posted

 Summer8906 Here's the mean pressure of the past 10 Februaries.

Must be a very dry month over to the south of us by now.

image.thumb.png.795489f9f0b24eac3cdc36f54603bb41.png

Compared to January which has seen a higher tendency for low pressure to cut into central Europe.

image.thumb.png.ffbfdf7d620177fe3f4035fa46ba5a18.png

Weirdly, December seems to be getting higher pressure almost everywhere - yet still ending up unfavourably for UK cold.

image.thumb.png.1d95e83cebf85d512bd8c24ccee972f5.png

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Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 LetItSnow I suspect one cause of the increasing tendency towards summer drought and wildfires in Greece is that high in February. As big a problem as hot summers is the lack of rainfall in the winter months: post-Christmas seems to be particularly bad in that respect (though Oct-Dec can be wet). The Mediterranean climate is "supposed to" be wet in winter but that seems to be less the case nowadays.

A most unfortunate mean pattern which does just about nowhere in Europe any good. Causes damp, gloomy weather here - but not enough rain elsewhere. The anticyclonic SW-lies also kill Alpine snow. Can that pattern be any worse?

I wonder what the mean would look like if you remove 2018 and 2023? More cyclonic for us I'm sure but with that high anomaly still over SE Europe.

Edited by Summer8906
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Posted
  • Location: SE Wales.
  • Weather Preferences: Cold snowy winters, mild/warm summers and varied shoulder seasons
  • Location: SE Wales.
Posted

Good question. I do have a theory that due to the Arctic region warming we aren't getting as much cold in autumn and early winter which means no cold to fire up the jet, set up a strong polar vortex or spawn lows hence more anticyclonic weather that time of year. It seems the only way we can get wet autumns those days is with NAO- regimes (Unlike NAO+ NAO- doesn't need as much energy to sustain wet cyclonic weather as you can just keep shoving in slack but very wet lows from the Azores/Biscay or get a stable Euro low).

 

By Feb we do get some solid cold with polar night still going strong so finally then you can get cold drop south and fire up the jet therefore lowmaking therefore wet zonal weather,typicaly you get westerlies and zonal set ups when you have a large temp gradient. Basically what used to happen in November or December now happens in February instead. This happened in Feb 2022 for sure (Winter 19-20 was just a freak show you had a very strong IOD+ which basically means the PV gets injected with borderline illegal experimental strong steroids).

Feb 2024 was different as I've mentioned a few times around here I wouldn't call Feb 2024 a fully zonal month at all it was very NAO- actually just a very west based one hence SWly lows for western Europe (The 2nd half did feature a more typical NAO+ zonal set up though).  The increase in zonal Febs is supported by the Feb map that LetitSnow posted above. Very classical NAO+ with what seems to be a low over the Iceland/Greenland area and a high over Europe hence westerlies and a pattern you'd associate more with early winter. 

Feb 2024 first half (Very textbook west based NAO-)
image.thumb.png.09b4b668701211db8cf1c6cb1846df3d.png

Feb 2024 2nd half (More typical zonal NAO+ pattern) 

image.thumb.png.cd6c977bfdd860e03374c93603e28a78.png


(BTW IOD+ means the western Indian Ocean is warmer than the eastern Indian Ocean and its linked to a strong PV over Greenland in winter hence Europe gets blasted with zonal turbo westerlies, I don't understand it fully though.) 

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Posted
  • Location: Coventry, 95m asl
  • Weather Preferences: Snow Nov - Feb. Thunderstorms, 20-29°C and sun any time!
  • Location: Coventry, 95m asl
Posted (edited)

Great post by @WYorksWeather on the sudden warm up in recent Februaries.

image.thumb.png.6bbb9ec4062687f91f85a104cbbf800d.png 

Shows up well on the graph they made. Very notable indeed and is quick becoming an early spring month (March) most years now.

image.thumb.png.af865633f084867249b7c7f849fe583a.png

 

Edited by Metwatch
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Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 Catbrainz Interesting theory, makes sense to me thinking about it.

We do often have a spell of zonality in December too albeit not as strong as that in February: while Dec 2021 and 2023 were very mild, dull and damp they didn't really have any notable storms, IIRC, just a long sequence of moderate-strength lows and much Tm air.

Regarding your wet autumns comment I have noticed that wet weather in October in particular seems to come from a different source than winter: it does indeed seem to be large, but somewhat slacker, lows on a more southerly track (west based NAO-) which have caused wet Octobers recently. I seem to remember October 2022 and 2023 featuring a lot of these kinds of lows, for example, also October 2024 to a somewhat lesser extent. Essentially the lows move through more slowly in autumn which means when it's wet it's very wet - but the quieter spells between the lows also seem somewhat more significant.

Edited by Summer8906
  • Like 2
Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 Metwatch Indeed. It is quite disturbing though, mild late winter more than any other time of year can have a really profound impact on nature.

Essentially these mild Februaries are ending spring early. May isn't really a proper spring month anymore, arguably, as a result - certainly not the second half. The best of the spring flowers are invariably over by May 21st and increasingly even May 10th-15th, with April being easily the peak month for spring beauty and March unambiguously a spring month when the weather is fine. The most beautiful Mays are those which followed atypically cold late winters or early springs - 2010, 2013 and 2016 being good recent examples. If the weather hadn't been so foul, May 2021 could potentially have been another one.

So the mild Februaries are both robbing time from winter (as cold and snow are rare in Feb now) and from spring (as May is increasingly being stripped of its natural beauty).

The only way spring is saved is if March and April are (on the one hand) fine and settled so we can enjoy spring's new peak or (on the other hand) cold so nature is delayed and May's classic beauty can be retained. 2022 is a good example of the former, while 2016 is the best example of the latter. 2024, on the other hand, was a complete disaster as we had an extremely mild February and then the peak spring months of March and April were dull and wet.

It's a shame this is happening in February more than any other month - it literally could not come at a worse time of year. If only comparable warming could occur in July or August, where it's perhaps most needed and welcome...

Edited by Summer8906
  • Like 3
Posted
  • Location: Coventry, 95m asl
  • Weather Preferences: Snow Nov - Feb. Thunderstorms, 20-29°C and sun any time!
  • Location: Coventry, 95m asl
Posted (edited)
6 hours ago, Summer8906 said:

So I'd expect, say, November, to be far more prone to huge lows as a result - yet Nov 2021 and 2024 were both mostly benign

This is mainly because of what happens in Asia (mostly the east half) and the Pacific. They're indirectly the main drivers of the downstream pattern over the North Atlantic / NW Europe along with the stratospheric polar vortex in the cold half of the year. They're very often different each year, leading to different conditions from month to month in the UK.

You've got the MJO (tropical convection in the Pacific which the outflow of that convection affects the jetstreams), then the global wind osciliations / atomospheric angular momentum which is to do with upper level wind budget in the troposphere and earth's rotation, which is also linked with the mountain torques depending on the pressure pattern in east Asia (Himalayas). Those then influence the jetstream further north in the Pacific, and eventually leading to downstream effects in north America and the Atlantic. The Atlantic sea surface temps and Europe itself alone isn't a major driver of the more local synoptic pattern.

Just following from what some of the posters who post about the teleconnections in the mod thread though. Still learning which phases lead to what patterns closer to our shores 😅 but usually positive AAM will lead to more blocking meaning -NAO and often wet if it's west based.

 

There are some guides on this forum for all of that i've found in recent years:

 

Edited by Metwatch
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Posted
  • Location: West Yorkshire
  • Location: West Yorkshire
Posted

 LetItSnow  Metwatch The most striking bit is probably that the linear warming trend for February over the last 30 years is now at 0.5C per decade. That's ludicrously fast. If the trend continued, it would imply that a typical February in the 2050s would be as mild as a 1961-1990 November. Looking further ahead, towards the end of the century, a typical February would be as mild as a 1961-1990 April!

I do think this warming trend for February might slow down or balance out a bit with the other months, in the sense that some of it is just statistical variance. Hence that extrapolation is probably not valid, but even at a slower 0.3C to 0.4C per decade it'd still be quite transformative in only a few decades.

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Posted
  • Location: Islington, C. London.
  • Location: Islington, C. London.
Posted

 WYorksWeather another fact about it which makes it so ludicrous is that with the average being 5.4 it makes a very tame February 3.8 be 1.6° below average which is the 1961 to 1990 average. So an average February then would be 1.6° colder than average today which would be the equivalent of a 2.2 C February back then. bonkers!

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Posted
  • Location: West Yorkshire
  • Location: West Yorkshire
Posted

 LetItSnow Or taking it to extremes, relative to average, a February below 3C (historically only about the coldest quarter) is now about as extreme to the modern average as a February like last year.

Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 WYorksWeather So examples of that might include February 1983 (mean temp 2.5C at Heathrow so CET even lower) or even 1981 (mean temp 3.5C at Heathrow so CET could have been below 3C).

1983 did feature snow and was generally cold but it certainly didn't feel extreme. 1981 just felt like a normal February in my limited experience at the time: frosty, settled, and a brief fall of snow.

I would consider only one February of my lifetime extremely or severely cold, and that was 1986. All the other cold ones, including 1983, 1985 and 1991, merely felt rather cold but nothing extreme. By contrast I would consider a vast array of Februaries extremely or "severely" mild.

In my head I'm still on 61-90 though, so every February since 2019 has felt anything from mild to silly-mild. Last February I would consider "normal" in my head would be 2018.

 

Edited by Summer8906
  • Like 1
Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 WYorksWeather It would be interesting to see whether it is indeed just a blip due to natural variation, we've just been unlucky (depending on POV) to have a cluster of very mild, zonal, Atlantic-dominated Februaries of late in the same way that we had a cluster of warm, sunny and dry Julys (and summers in general) from 1989 to 2006 which was perhaps historically atypical - or a cluster of cold winters from 2009 to 2013.

Perhaps Feb 2026 will be the coldest since 1991 and we won't see a Feb with above 5C CET from 2026-2029, you never know. But if the mild trend continues for the rest of the decade I guess we can conclude that it's a permanent feature.

Edited by Summer8906
Posted
  • Location: Hampshire
  • Weather Preferences: Warm-by-day sunny thundery summers , short cold snowy winters.
  • Location: Hampshire
Posted (edited)

 LetItSnow Interesting the 30-year rolling average is now 5.4, that is equivalent to the Heathrow mean for February 1982, a month I considered at the time to be thoroughly and unambiguously mild and, when the sun shone, spring-like.

So Feb 1982, one of the three mildest Februaries of the 80s, would now be considered a cold Feb (as the CET must have been below the Heathrow mean)! Now that is frightening.

Feb 1988 likewise with 5.25 mean at Heathrow, a month that was generally on the mild side but did turn somewhat chilly later.

Essentially what we're saying is that the 1995-2024 mean is milder than 8 out of the 10 Februaries of the 80s, including two months I considered mild at the time, and every February from 1981-88.

 

Edited by Summer8906
  • Like 1
Posted
  • Location: Cleeve, North Somerset
  • Weather Preferences: Continental winters & summers.
  • Location: Cleeve, North Somerset
Posted
19 minutes ago, Summer8906 said:

So Feb 1982, one of the three mildest Februaries of the 80s, would now be considered a cold Feb

5.4°C I would still consider mild in Feb. 6 very mild, 7 exceptionally mild, 8+ simply not Feb!

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Posted
  • Location: SE Wales.
  • Weather Preferences: Cold snowy winters, mild/warm summers and varied shoulder seasons
  • Location: SE Wales.
Posted

If I had to say what I’d classify as a mild Feb going by the likely 2010-2040 average for Heathrow (since that’s basically what we have now being midway into the period)

Mild=10/3

Very mild= 12/5

Record breaker=15/8

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Posted
  • Location: Newington, Edinburgh
  • Weather Preferences: The seasons as they should be
  • Location: Newington, Edinburgh
Posted

 WYorksWeather I suspect that rate of warming will slow down. Mean February temperatures did slowly dip through the 20th century (RJS drew my attention to this in past CET threads, and it's also apparent on your plot) despite background temperatures rising.

My guess is that the recent rapid rise is due to a bounce-back from a naturally-driven cooling trend atop steadily increasing baseline temperatures.

Posted
  • Location: West Yorkshire
  • Location: West Yorkshire
Posted

 currents So do I. I think working from the background rates, I'd expect an equilibrium somewhere around 0.4C per decade for the UK on the whole. Background warming rate is now at least 0.25C per decade, and the UK is warming faster than the global average (ocean warms slower). But that is still incredibly fast. Pinning it down to February specifically is harder of course - there will be a mixture of weather-related variation and background warming to consider.

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Posted
  • Location: Irlam
  • Location: Irlam
Posted (edited)

I posted this some years ago on the strange run of mild Februarys during  the Victorian era. 

 

Edited by Weather-history
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  • Like 3
Posted
  • Location: Perth, Scotland
  • Location: Perth, Scotland
Posted

I feel recently with winters, January has been becoming more settled, colder and much sunnier whereas February is generally getting much milder, wetter and stormier. Almost like they have swapped completely. The February’s of 2024, 2022, 2020, 2017, 2014, 2011 were all wet, mild and dull. Whereas here all January’s since 2019 have been significantly sunnier than average and often much drier than average. (2025 is on par to be similar as well). The January’s of 2022, 2021, 2019, 2017, 2015, 2012 were all very dry and very sunny. One exception I would say especially in the north was February 2021 which brought some extremely low temperatures and significant snowfall to the north. 
 

My first weather memories were generally January’s being mainly mild , unsettled, wet and stormy with the occasional heavy snowfall and the odd very cold spell. February’s I always remember being much more settled, often colder with many heavy frosts, ice but generally pleasantly calm and cold sunny days. In recent years however it’s been January that has delivered that type of weather and then February has generally been much more unsettled. Glad it’s not just me that’s noticed this.

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Posted
  • Location: Twickenham, London
  • Weather Preferences: Csa/Csb
  • Location: Twickenham, London
Posted

In which average set will February break the 10c average high here - 2001-2030 or 2011-2040? The most up to date February average high is 9.0c at Heathrow and 9.2c at Kew.

I feel that February, especially the 2nd half of the month, feels more like early spring than winter. Plenty of insects around, plants budding, some flowers/blossoms out.

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