The anti-2023

[LetItSnow!]

Reviving this. Since @Summer8906 mentioned anti-seasonal years being flipped, here's 1974 flipped using my "special methodology". I'm just flipping the Met Office Monthly Weather Report and the C.E.T./rainfall as well as inversed 500mb height anomalies.

The anti-1974 (or 4971!):

January: Cold and anticyclonic. The month was mostly, dry and with high pressure. Freezing fog became widespread on some days, particularly the 8th and the 12th when cold air aloft combined with high pressure readings led to a spectacular Hoar frost. Winds were often light and blew from the north and east with no great gales during the month. Nonetheless, the month started mild with the 1st being bright, sunny and mild with a false sense of spring. Temperatures anomalies saw the biggest departure from normal in the south-east where temperatures ranged from 2.5°C to 5°C below normal, meanwhile across Scotland frosts weren't as frequent due to milder air making inroads at times. The mid-month period was very cold across the country and notably so in the south-east with temperatures falling below -10°C on several nights peaking on the 17th as temperatures fell around the -15°C mark in sheltered areas. It was driest January across Scotland in almost 50 years and in 14 years for the UK as a whole. Parts of central Scotland saw less than 30% of the average rainfall. Meanwhile, some northern, eastern and southern England were rather "wet" due to persistent, though mostly light snowfalls. The 6th to the 11th was particularly snowy with the south coast seeing significant accumulations on the 8th leading to people being trapped in their cars with main routes becoming impassible. Further heavy snowfall, this time focused on East Anglia gave some significant totals on the 17th and 18th. It tended to be dull in most places though not exceptionally so and there were no extended gloomy periods. It was sunny in western Scotland. (0.3 / 53mm)

February: Dry, cold and anticyclonic. High pressure dominated until the 17th but more unsettled weather took place for a time after that. When high pressure dominated, the weather was mostly settled, frosty and foggy with frequent but light snowfalls. Some days were pleasant in sunny spells but nights were cold. After this it became windy and showery with these being of hail, sleet and snow. Pressure was particularly high from the 6th to 12th and this created disruption due to thick freezing fog. Temperatures were below average everywhere though it was less cold in the west than the east with temperatures ranging from 1°C to 4°C below normal. The 21st was a freezing cold day with a notably cold airmass from the east giving the coldest day of the century across the south. It was very dry with large parts of the south only having a quarter or so the normal rainfall. The month was mostly bone dry up until the 17th apart from light snow showers. Snowfall became more widespread and heavier thereafter. Sunshine followed the same pattern as January and was mostly dull but sunny in parts of Scotland. (2.0 / 36mm)

March: Sunny but unsettled with infrequent settled periods. The first half of the month was rather mild but it became colder later. Wet and windy weather dominated, especially in the third week. Eastern and southern areas were often dull after the 21st. Winds were often strong to gale force in the first half but became more easterly in the second-half. A taste of spring from the 9th to the 11th with temperatures into the mid-teens widely. Colder in the second half with some particularly raw daytime highs. The closing days were particularly cold with temperatures falling into double digits in places. Some isolated parts were dry but most areas were wet. Most areas were sunny. (5.5 / 93mm)

April: Extremely wet. Dull in the west, sunny in the east. Low pressure was over the country for virtually the entire month bar some higher pressure in the south on the 27th and 28th. The first ten days saw lots of cloudy, wet weather with low temperatures by day but mild minima, though parts of the east that were sheltered from the westerlies were sunnier. Winds were often quite strong and mainly from the west, though some days in the south were sheltered from this at times. Rainfall was around double the average in every region, though anomalies were extreme in parts of the north-west and across East Anglia where anomalies exceeded 400% in places. Much of northern England/Scotland saw rainfall every day of the month. The 11th and 12th were the only mostly dry days of the month. It was mostly dull to very dull, but isolated eastern coastal districts enjoyed a sunny April. (8.0 / 160mm)

May: Unsettled. Dry in some western areas but exceptionally wet in the east. Despite pressure being relatively high, several very wet spells that occured throughout the month made it very wet overall. Winds were mostly westerly but turned easterly in the final ten days. There were no strong gales but it was rarely settled. The first half was very warm at times. The 8th was the warmest day so early in the year for almost 40 years with temperatures widely into the mid/upper 20s. Another notably warm day on the 12th. Temperatures plummeted in the second half and there were air frosts as far south as East Anglia by the 18th. Away from Northern Ireland, western Scotland, western parts of Wales and the south-west which were dry, everywhere else was wet. It was particularly wet across East Anglia and north-eastern coastal regions. Tynemouth had its wettest May for 48 years and the usually dry East Anglia saw totals of over 100mm, even more notable for following an extremely wet April. Where it was dry it tended to be sunny but most places were dull. There were some long dull spells mid-month and towards the closing days, mostly in the east. (11.8 / 116mm)

June: Changeable. Mostly fine but punctuated by some wet spells. Winds were mostly easterly from the 1st to the 11th and were mostly light leading to some beautiful conditions, especially inland and out west with temperatures widely in the mid/upper 20s away from eastern coasts where fog could be hard to clear. The 6th saw a notably high pressure readings. Settled, warm conditions were replaced with cool westerlies mid-month and it became unsettled, wet and windy at times. It became cool mid-month with temperatures pegged back into the mid-teens Celsius in many places and again in the final ten days, though no exceptionally cold weather occured. Rainfall varied somewhat but it was generally wet further north-west and dry further south-east. Sunshine totals weren't exceptional in any regard in most places, with the north-west tending to be dull and further south-east it tended to be sunny. Despite cool and unsettled spells in the second-half at times there were no protracted dull spells and sunshine was never far away. (15.1 / 64mm)

July: Changeable but hot. High pressure was often in the vicinity, but positioned just far north to allow frequent disturbances to the weather, these usually being of a humid and thundery type rather than typical Atlantic dominated weather. Pressure was often weak with little in the way of big low pressure systems. It was a humid month with frequent thunderstorms meaning that it had the unusual distinction of being very warm but wet. Winds mostly blew from the east and were slack leading to slow moving downpours which lead to very high rainfall totals in places. Temperatures ranged from 1°C to 2.5°C above normal. There was  There was a cooler spell around the 8th and again around the 20th but for most areas in the south the temperature exceeded at least 21°C every day of the month and no notably low temperatures occured. The north-west tended to be driest and avoided the brunt of convective activity so it was dry here but it was very wet in parts of East Anglia and the south-east with totals over double the norm. Flash flooding was commonplace. Sunshine was above average in most areas but it tended to be duller in the north and very dull in the north-west. (17.5 / 94mm)

August: Warm and mostly settled but dull. High pressure was in the ascendancy for the most part but low pressure interludes did occur at times though they weren't overly potent. Most of the month was mostly dry but punctuated by normal wet spells at times meaning rain was rather infrequent. For a settled month it was rather breezy at times with winds often from the north and east. It tended to be warmer (relatively) the further north and west whereas some eastern coastal locations were slightly cooler than average. There tended to be a lot of inoffensive weather with pleasant days. There were no notably cool or dull spells and this helped boost the average, but likewise there was little in the way of excessive heat. East Anglia and the southeast were rather wet, but most places were dry. (16.7 / 70mm)

September: Very warm and settled. High pressure dominated all month with very high readings at times. Any troughs were very weak and short lived. The month was mostly dry, settled and mostly very warm/hot at times. Rainfall was scarce and even in the more unsettled spells many places stayed dry. There were some isolated thunderstorms in the south at the end of the month. High pressure built in and by the 2nd it had turned hot with the first week having hot sunshine and very high pressure. The month was warm everywhere, ranging from slightly warmer than average in the far north to as much as 4°C above normal in parts of the south and west. After a cooler phase it turned very warm again during the final two weeks and by the 27th temperatures were back in the upper 20s Celsius across southern England. Plymouth saw no measurable rain all month. Despite the settled weather, parts of Scotland were rather dull, but England was sunny. (15.6 / 27mm)

October: Warm and changeable. It was settled in the south but unsettled in the north. Winds often blew from the south-west and the south-east and were mostly light. Temperatures were above average everywhere but especially so in the south-east where anomalies were as much as 4°C above normal. Except for a few cooler days warmer than average weather persisted the whole month and many parts of the UK failed to record a single frost. It was wet in the north-west but in the south-east corner it was exceptionally dry with less than a third the normal rainfall in parts. It technically was an official drought as some places saw no rainfall for a month. Away from the SE there wet weather at times with unusual intensity aided by very warm air often associated with it, but there was some fine weather inbetween the deluges. The dry conditions were met in some places in the south-east with severe thunderstorms on the 28th. The north-west was very dull due to moisture laden air bringing lots of cloud, but elsewhere it was a sunny October. (12.8 / 105mm)

November: Dry and settled. High pressure dominated the month and while there were unsettled spells, they were mostly short-lived. In a change from the autumn so far, it was quite chilly as winds tended to blow from the east and north though mostly gentle winds. The 11th to the 14th was very foggy with freezing fog in places causing disruption, an abrupt change to the abnormally warm frost-free weather that had dominated so far. Further foggy anticyclonic gloom dominated from the 24th to the 26th. Temperatures didn't stray that far from normal anywhere with anomalies being around 1°C, mostly cold across England but rather mild in the far north. In the south-east that escaped the rainfall in October it topped off an extremely dry autumn as November was very dry. East Anglia and the south-east saw less than half of the average rainfall. Sunshine varied due to the persistance of fog in places, but it tended to be dull in the south in and sunny in the north. Parts of Essex had the dullest November of the century. (5.9 / 65mm)

December: Extremely cold and snowy. Exceptionally cold weather prevailed. Snowfall occured at times, especially in the south and east where falls were significant at times, meanwhile it was very dry in Scotland. Fog often formed inland. Winds were from a northerly or easterly quadrant almost all month. London was inundated with its heaviest snowfall in years on the 11th where rapid falling snow and light winds created a winter wonderland scene quickly. A week of heavy snowfalls created travel mayhem for Christmas as roads were impossible to navigate by the 17th as snowfall made roads dangerous and trees and branches snapped from the weight of the snow. It was the coldest December for 40 years and contrasted with the exceptional warmth of September and October. Severe cold set in on the 20th after a brief thaw mid-month and temperatures fell so low that it was enough to kill some plant life. The temperature didn't get above freezing after the 20th in snow covered parts. While Scotland saw little in the way of disruptive snow, snow was heavy enough to collapse roofs in Kent on the 11th. Sunshine followed the usual pattern in blocked months with Scotland and sheltered western parts being very sunny but the east being very dull. (-0.3 / 109mm)

Annual CET: 9.27°C

Annual rainfall: 996mm

Edited March 7 by LetItSnow!

[LetItSnow!]

Here's an interesting one, the anti-1740. The real 1740 is by far the coldest year ever recorded. Using the C.E.T. and limited data/reports from this year, here's what its anti may look like. I imagine a year in the 2020s or 2030s could read like this, so it's written in the style of that rather than as "anti-1740". The C.E.T.s are not calculated by the opposite anomaly but by each months relative ranking in the C.E.T.

Jan 7.1 Feb 7.3 Mar 6.8 Apr 9.7 May 13.9 Jun 16.0 Jul 16.5 Aug 16.7 Sep 12.8 Oct 14.3 Nov 9.2 Dec 6.0 - 11.36C

This winter was extremely mild. It included a notably mild January and February, both of which were in the 'top-5' of coldest such-named months. Using the CET series, both January and February averaged above 7.0C, the only time this has ever occured. An exceptionally severe south-westerly gale on the 11th of January accomapnied by remarkably mild temperatures in the mid-teens. London saw its most damaging windstorm since 1703. Much of southern England was completely frost free during both January and February. A notably wet January across England & Wales. Heavy rainfall over the winter culminated in severe flooding in March.

Following a warm winter, a notably warm spring. Temperatures on the 16th of May rose to 32C in London, breaking the record for the earliest 90F ever recorded. A very warm June followed.

After a period of unexceptional temperatures from July to September the anomalous warmth returned in October, breaking the record for warmest such-named month by over 1C. Unusually warm from the 9th to the 12th of October with temperatures into the upper 20s.

Alternatively, the C.E.Ts relative to their rankings at the time instead of all time.

Jan 7.5 Feb 8.5 Mar 7.9 Apr 10.5 May 13.8 Jun 17.0 Jul 18.0 Aug 18.0 Sep 11.5 Oct 14.3 Nov 8.6 Dec 7.3 - 11.91C

Edited April 20 by LetItSnow!

[Summer8906]

 LetItSnow! Interesting on the anti-1974, certainly a lot of extremes though the summer anti-1974 does not sound exceptional for dry, sunny weather - an indication that the real summer 1974, despite being cool, wasn't as bad as all that?

[B87]

An anti 1954 or 1958 would be great.

London anti-1954

Av max/rainfall

Jan: 10.9c / 94.1mm

Feb: 11.9c / 38.5mm

Mar: 13.0c / 26.3mm

Apr: 16.8c / 75.5mm

May: 20.0c / 39.2mm

Jun: 24.6c / 23.7mm

Jul: 28.6c / 29.5mm

Aug: 27.0c / 17.9mm

Sep: 22.4c / 41.1mm

Oct: 14.8c / 76.1mm

Nov: 10.9c / 37.7mm

Dec: 7.9c / 67.6mm

 

A very mediterranean precipitation pattern, a dry summer with the hottest July on record. Jan-Sep with above average temperatures. Oct-Dec below average.

Edited Friday at 16:07 by B87

[LetItSnow!]

 B87 I’ll take a look at the Met Office reports and conjure up a anti report 

[Summer8906]

I guess it's time for an update on the anti-2024.

I think I did both Jan and Feb, so to continue with March:

The month started anticyclonic and dry with variable cloud and temps close to normal. A rather cold and dull cyclonic N-ly with a long sea track over the North Sea intervened for a few days around the 8th, before a much drier and anticyclonic NE-ly type set in for the following two weeks. As a result it was sunny, dry, cold by day and extremely cold by night. Places exposed to the east wind had occasional wintry showers and one or two disturbances in the flow produced longer periods of snow, though these soon melted in the increasingly strong sunshine.

For the weekend of the 23rd/24th the high pressure shifted eastwards allowing a cloudy and rather hazy though still dry SE-ly intervene for a couple of days. Temps climbed to near average. Finally a straight anticyclonic type took over for the final week and it was sunny by day with one or two days seeing temps exceed the normal for the first time in the month. Easter Saturday despite being anticyclonic saw a weak frontal system produce extensive drizzle though Easter Sunday produced very stable and anticyclonic conditions with variable cloud.

Overall, cold, dry and sunny.

And, while the month is not over yet, the direction of travel is apparent so April:

The 1st featured a keen easterly wind as the high of late March moved a little north and it was rather dull and cold but also dry. Easterlies and occasional northerlies took hold for the first 10 days and produced distinctly cold conditions both day and night, with conditions very reminiscent of (real) early April 2013. Exposed parts had some further wintry showers but overall it was very sunny. A notable feature was the polar low feature which moved SSW-wards on Saturday 6th producing a spell of heavy snow for most areas, even in the south. That day was also somewhat dull but the sunshine returned on the 7th which melted the snow cover, in the same manner as the similar April (real) 2008 event.

The 11th and 12th saw a low over the continent gain more influence and as a result, while remaining cold, it turned rather showery particularly to the south.

From the 15th a change of type occurred with a large Atlantic low drawing up southerlies. It turned very much warmer with temps around 17C or so widely, but the proximity of the low meant a lot of cloud around, and wavering fronts brought up pulses of occasionally heavy rain. There were drier days too, but they were very dull. It was unseasonably humid and damp. The 20th and 21st were particularly poor with the low centred over the country and extensive heavy rain, though the southerlies kept it mild.

From the 22nd the low withdrew into the Atlantic and a spell of anticyclonic southerlies produced drier and sunnier conditions, with a few showers to the west. Towards the east temps reached the low 20s for the first time in the year.

At the end of the month the southerly flow was cut off and a more general anticyclonic type returned temps to near normal but it remained dry and sunny.

Overall, dry, sunny and somewhat below normal though with a distinct contrast between a very cold first half and somewhat warm second half.

To this point, all four months of anti-2024 have been dry and below normal, and three have been sunny.

Edited Friday at 15:58 by Summer8906

[Summer8906]

 B87 Was Jan 1954 extremely cold?

An average max of 10.9 suggests an exceedingly mild month (around +4 above normal by max) but didn't think Jan 1954 had a -4 anomaly for maxima. I remember going through the 50s winters some time ago and don't remember Jan 1954 being especially cold.

Edited Friday at 16:20 by Summer8906

[B87]

 LetItSnow! Heathrow anti-1958

Av max/rainfall/sun hours

Jan: 10.0c / 53.3mm / 82.1 hrs

Feb: 9.1c / 31.3mm / 111.9 hrs

Mar: 15.3c / 51.6mm / 143.7 hrs

Apr: 17.7c / 55.1mm / 200.2 hrs

May: 19.5c / 32.3mm / 225.8 hrs

Jun: 23.8c / 21.5mm / 264.6 hrs

Jul: 26.1c / 39.7mm / 245.1 hrs

Aug: 26.0c / 30.4mm / 301.1 hrs

Sep: 20.4c / 15.4mm / 179.4 hrs

Oct: 16.7c / 79.5mm / 136.2 hrs

Nov: 13.3c / 82.5mm / 100.6 hrs

Dec: 9.6c / 29.1mm / 80.4 hrs

 Summer8906 it had an average max of 5.9c in the real world, 2.5c below average. The Jan avg max is 8.4c.

Edited Friday at 16:22 by B87

[Summer8906]

 B87 was the Jan average max for any 30-year period including 1954 as high as 8.4 though?

8.4 sounds like a climate-change-influenced 1991-2020 value, rather than the typical value for the second half of the 20th century.

[B87]

 Summer8906 I used the current averages to see how an anti-1954 or 1958 would end up today.

The 61-90 average, which was one of the colder 20th century averages, was 7.1c for January. The 1900-1930 average high for January at Greenwich was 7.6c.

Edited Friday at 16:27 by B87

[Summer8906]

 B87 Ah OK. To be honest though perhaps we need to use the anomaly of 1954 with respect to one of the 30-year periods containing it, which would be around -1 assuming 61-90 is similar to 51-80.

So arguably, an anti Jan 1954 should really have a +1 anomaly with respect to whatever time period you want to set it in.

Edited Friday at 16:33 by Summer8906

[B87]

Created the anti 2008, which was probably the worst individual year since 2000 (even worse than 2021). Even with the colder start to the year, it ends up far superior to the real life 2008, which was a cold, dull and wet mess. July and August actually deliver summer like weather this time, while the decreased sunshine in June doesnt really matter as much once March, April, May, July, August and September actually deliver.

Jan: 6.4c / 48.6mm / 57.6 hrs

Feb: 7.0c / 74.6mm / 19.7 hrs

Mar: 12.8c / 7.8mm / 155.3 hrs

Apr: 16.3c / 21.2mm / 199.1 hrs

May: 17.0c / 27.6mm / 232.1 hrs

Jun: 22.4c / 49.0mm / 189.9 hrs

Jul: 25.0c / 14.8mm / 239.5 hrs

Aug: 25.3c / 41.2mm / 284.7 hrs

Sep: 21.9c / 56.2mm / 191.1 hrs

Oct: 16.6c / 85.2mm / 85.8 hrs

Nov: 12.3c / 74.4mm / 95.1 hrs

Dec: 10.3c / 73.0mm / 40.9 hrs

Edited Friday at 17:02 by B87