The summer [JJAJJAMeteorological Summer comprising the months June, July & August] consisted of the fifth warmest (mean anomaly +2.4°C) June in central England, followed by the two non-descript months of July (mean anomaly -0.7°C) and August (mean anomaly -0.2°C). You’ll notice that there were no warm spells to speak of after the 25th of June, when the summer switched to average mode. The June 10th to the 16th was a quite remarkable spell, setting 7 consecutive new maximum daily temperatures for June. The rest of the summer also set five new high daily minimum records and one for the lowest minimum on the 26th of July (8.6°C).
Summer started in a very anticyclonic mood with negative zonality (E’lies). The rot soon set in, and by the 19th of June the summer had turned when positive zonality (W’lies) was restored, and that’s basically where we’ve been since then. The meridional index has switched between spells of negative and positive, as it tends to do across our part of the world, and generally cyclonic. There were a couple of days with a gale index above the threshold of 30, but neither tie in with the named storms of Antoni (5 Aug) or Betty (18-19 Aug). The UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy, in their wisdom, decided not to name the deep low on the 15th of July that produced a GIGIGale Index of 40.5, but I reckon it was the equal of either of the two that were named.
You may have noticed that I’ve put some work into smartening up the front end of my application that visualises objective LWTLWTLamb Weather Types are often used in UK-based analyses, with individual weather patterns based on the eight primary cardinal directions (N, NE, E, SE, S, SW, W, NW) plus cyclonic (C), anticyclonic (A) and unclassified (U) types., the data for which I download from the CRU at the UEA. I’m quite proud of the app, and it works very well. I am so glad that the CRU have kept the objective series going after H.H.Lamb’s death in 1997. I do have the objective LWT algorithm, which I run on six hourly gridded reanalysis data in a seperate application as well , which gives a more detailed view of how weather types unfold.
Daily CETCETCentral England Temperature | 1 January 1772 – 25 August 2023 | 365 day moving average
This year might have seen the warmest month in global temperatures, but the warmest 365 days in the CET series still belongs to the 11.71°C which ended on the 2nd May 2007. The graph shows all the daily mean central England temperatures for each year since 1772, with 2022 in blue, 2023 in red and 2007 in black. Up until the middle of February, 2023 was out on top as the warmest in the series, but since then the average for 2023 has very slowly cooled, at the same time back in 2007 the 365 day average was still warming. At this juncture, by that I mean the 25th of August, 2022 is now the warmest 365 days but with a mean temperature still much lower than the record 11.71°C set in 2007. If this graph of multiple line series for each year since 1772 looks a little bit complicated, it is, so study it a moment, and I’m sure everything will become clear😉
00 UTCUTCCoordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). – 24 Dec 2016
On 20 UTC on the 23 December 2016, instrumental wave heights reported by the automatic weather buoy [MAWS] K5 out in the North Atlantic at 59.1° north and 11.7° west were as high as 15.4 metres or just over 50 feet. Wave heights have since dropped to around 30 feet, before increasing again tomorrow as storm Conor passed close by to the north. Looking at the midnight chart I should imagine waves may have been considerably higher than this a little further north judging by the strength of the gradient. Sadly, since I wrote the original article the UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy now suppress wave height data in their hourly weather buoy observations, so much for progress.
Hourly wave heights from K5Plotted observations from K5
How to recreate plotted weather charts with observations from the Daily Weather Report – yes it’s a bit of a mouthful as titles go but it’s what I’ve done over the Christmas holidays. The Daily Weather Reports [DWR] in question are the ones that the Met OfficeUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy have very kindly scanned and made available on their website. The daily reports extend back to September of 1860, but for a start I’m only interested in the years from around 1960 to 1972, after that I have my own 6 hourly observational data that I bought from Weather Graphics some years ago and have kept updated by means of OGIMET in recent years. So if you want interested at looking at a plotted synoptic chart for a particular day from January 1963, you could approach the Met Office and ask them to provide you with all the SYNOPSYNOPSYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting weather observations made by manned and automated weather stations. SYNOP reports are typically mad hourly and consist of groups of numbers (and slashes where data is not available) describing general weather information, such as the temperature, barometric pressure and visibility at a weather station. observations for the hour that you’re interested in, I haven’t done that personally, because I think the cost would be prohibitive. But there is another way, and that’s to download the PDFPDFPortable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992. of the DWR for January 1963 and extract the 55 observations that are contained within it and plot your own chart, and that’s exactly what I did:
Figure 1 – Observations for the 2nd of January 1962 at 18 UTCUTCCoordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). – courtesy of the Met Office and Crown Copyright
Download the PDF of the DWR for the month of January 1963 from the Met Office (~67 MB).
Cut and paste the observations for the hour that you are interested in (00, 06, 12 or 18) as a JPEG from the PDF.
Use a good OCR application to create a text file from the JPEG.
Write an application to allow you to edit the text file returned by the OCR application to verify and edit each observation.
Use the application to convert the old format SYNOP into the new format.
Download the reanalysis MSLPMSLPMean sea level pressure is the pressure at sea level, or, when measured at a given elevation on land, the station pressure reduced to sea level assuming an isothermal layer at the station temperature. pressure data for 1963 (~19 MB) from the NCEPNCEPThe United States National Centers for Environmental Prediction (NCEP) delivers national and global weather, water, climate and space weather guidance, forecasts, warnings and analyses to its Partners and External User Communities. site, convert the NetCDF format into plain text using NCDUMP, parse that gridded text into individual MSLP data files for each main synoptic hour for that year.
Inject the MSLP 2.5° x 2.5° gridded data values for 18 UTC on the 2nd of January 1963 from the data file you created in step 6 as a background field to improve the MSLP contouring, along with all the SYNOP observations that you created in step 5 into your SYNOP viewer, ensuring that you have all the locations of the old observing sites (such as Spurn Head and Cape Wrath) in your stations database so you can plot them!
Generate a screenshot of the British Isles for 18 UTC and add it into you blog.
And that my friends, is all there is to it.
Optical Character Recognition
I have found one thing from this exercise and that OCR software is not a great deal better than it was 20 years ago when I first used it. None of the free and online OCR web services work at all well, and none of them allowed you to choose numeric only input. Some of the results were so bad that the numeric results have been converted into the equivalent of a piece of Shakespeare in the Infinite monkey theorem! I tried to sharpen and reduce the number of colours to no avail, I cut and pasted and saved as high quality JPEG, PNG, TIFFTIFFTag Image File Format, abbreviated TIFF or TIF, is an image file format for storing raster graphics images. and PDF without any improvement in character recognition. Just at the point of giving it all up as a bad job I decided to download a trial of Abbyy PDF Creator+ and at first found the results were equally as poor, until I noticed that if I set the language to digits the results were very much better, probably around 90% of the numeric characters in the observations were now correct.
The final result
And so here is the finished product (fig 2), more than 60 years after the observations were made. I was still a little young to be involved with making one of the 55 observations quite yet, but I did spot a typo in the original DWR, it occurred in the 03715 Rhoose observation, and although I would for a bit of fun like to submit a correction to it to the Met Office help desk, they’d probably not see the funny side of it 60 years after the event as I do!
Fig 2 – 18 UTC Observations for 2 January 1963 – courtesy of xmetman
Of course the perfect answer to my conundrum would be for the Met Office to make all their archived SYNOP observations freely accessible, but I don’t see that happening anytime soon, but if you’re as daft as I am, and follow the steps that I’ve outlined above, you too could step back in time and recreate a plotted weather chart from the 1960’s.
Fig 3 2nd January 1962 18 UTC – courtesy of the Met Office and Crown CopyrightFig 4 18 UTC 2 January 1963 – courtesy of NCEP reanalysis
According to the 42 day forecast for 2M temperatures from the ECMWFECMWFThe European Centre for Medium-Range Weather Forecasts is an independent intergovernmental organisation supported by most of the nations of Europe. It is based at three sites: Shinfield Park, Reading, United Kingdom; Bologna, Italy; and Bonn, Germany. It operates one of the largest supercomputer complexes in Europe and the world's largest archive of numerical weather prediction data., it looks likely to be a mild, if not warm start to meteorological autumn 2023 across much of Europe. Let’s hope they’re forecast is wrong, it has been before.
The maximum temperature of 46.8°C at Valencia Airport on the 10th of August 2023 was an amazing 15.8°C above the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO.. Anomalies in other parts of Spain where ~6°C above the LTA. It was slightly cooler in the city of Valencia itself with a maximum of 45.1°C and anomaly of 14.4°C. The blisteringly high temperatures were in no doubt helped along by a strong foehnFoehnA foehn, is a type of dry, relatively warm, downslope wind that occurs in the lee (downwind side) of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward slopes (see orographic lift). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. wind blowing down from the mountains to the west. At 13 UTCUTCCoordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). they lifted the temperature from 40.5°C to 46.0°C (RH ~10%). By 15 UTC the sea breeze arrived with winds backing into the ENE and dropping temperatures to 34.0°C. Unusual, but you would have thought this must have happened countless other times in the past.
I reworked a graph in my Tropical Cyclone Program to help visualise the state of the hurricane season in the North Atlantic. More tricky than I anticipated but it does show that I was correct in thinking it was indeed a slow start despite the record SSTSSTSea Surface Temperatures in the Atlantic this year. If things follow the climatology, activity will gradually increase during August, reaching a peak in early September.
A wet month in some parts of Nova Scotia in July by the looks of these totals. I don’t have LTALTALong Term Average. This is usually defined as a 30 year period by the WMO. data for these places so can’t provide anomalies as I would like. But undeniable evidence of global boiling or the result of flash flooding from thunderstorms?
As always the mean pressure chart can reveal a lot about the weather, and in July 2023 it showed why it was so wet and changeable, with near average temperatures across the British Isles. It’s also apparent from it why Iceland was so cold due to the squeeze in the pressure gradient between higher than average pressure across Greenland, and lower than average pressure across NW Europe, resulting in a persistent and strong N or NENENorth East flow of air across the island. It’s not so revealing about the causes of the heatwave across North Africa, which happened in a very slack pressure field in a ridge of high pressure that extended eastward into the Mediterranean from the Azores high.
It’s official – July 2023 was not only the warmest July on record, but it was also the warmest month on record too, and it did it by a massive margin of 0.16°C (in global temperature terms) from the July of 2016😮. That’s according to mean temperature estimates from my DIYDIYDo It Yourself global temperature series that extend back to 1948, and which I derive from reanalysis data I download from NOAANOAANOAA is an agency in the Department of Commerce that maps the oceans and conserves their living resources; predicts changes to the earth's environment; provides weather reports and forecasts floods and hurricanes and other natural disasters related to weather.. Despite this I notice that the linear trend for July mean temperatures is still only 0.91°C per decade🤔. The daily global mean temperature has been at unprecedented levels too for much of the summer and still is, but has now started to cool off as the globe cools down as we head to the boreal Autumn.
One of the main reasons why this summer 2023 is so warm is the sudden increase in temperatures across the tropics, no doubt brought about from the switch from La NinaLa NiñaLa Niña is an oceanic and atmospheric phenomenon that is the colder counterpart of El Niño, as part of the broader El Niño–Southern Oscillation climate pattern. The name La Niña originates from Spanish for "the girl", by analogy to El Niño, meaning "the boy". In the past, it was also called an anti-El Niño[1] and El Viejo, meaning "the old man." to El NinoEl NiñoEl Niño 'The Boy' is the warm phase of the El Niño–Southern Oscillation and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific conditions this spring. This graph shows the sharp rise quite dramatically.
What surprised me about temperatures in July 2023 was how the media went on a frenzy and adopted what was a North African heatwave and described it as an whole encompassing European affair, when mean temperatures across a large part of the continent for much of the month were below average.🤔
Well the first thing to say is that low’s are not at all unusual in August. Remember the Fasnet storm of 13 August 1979? Tomorrow’s low has a forecast central pressure of 983 hPahPaA Hectopascal is the SI unit of pressure and identical to the Millibar for midday and is situated close to Birmingham. Below is a graphic of charts drawn using reanalysis data from 1948 so you can make your own minds up. The one that immediately stands out to me is the chart for the 2nd of August 1986, with a GIGIGale Index of 38. Remember this chart uses reanalysis data in a coarse 2.5°x2.5° grid of MSLPMSLPMean sea level pressure is the pressure at sea level, or, when measured at a given elevation on land, the station pressure reduced to sea level assuming an isothermal layer at the station temperature. values so contours may well be lower.
It just so happens that I have this chart, but as you can see the low close to Tiree is already a filling feature, with a minimum central pressure of 988 hPa at 06 UTCUTCCoordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT)., and can’t match the forecast depth of tomorrow’s low. So tomorrow’s low looks very unusual, and is likely the deepest low to affect the UKUKThe United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. on this date in over 75 years!
As you can see the colour scale I use for temperature is dynamic rather than using a fixed set of colours as preferred by the BBCBBCThe British Broadcasting Corporation (BBC) is the national broadcaster of the United Kingdom, based at Broadcasting House in London. It is the world's oldest national broadcaster, and the largest broadcaster in the world by number of employees, employing over 22,000 staff in total, of whom approximately 19,000 are in public-sector broadcasting. and UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy. It may not be transferable and directly comparable to any other month, but I find it much easier to find the hot and cold spots, and I can easily switch back to a fixed scale in software if necessary.
As far as I can see in the SYNOPSYNOPSYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting weather observations made by manned and automated weather stations. SYNOP reports are typically mad hourly and consist of groups of numbers (and slashes where data is not available) describing general weather information, such as the temperature, barometric pressure and visibility at a weather station. observations that I’ve downloaded for July 2023, and in complete contrast to July 2022 when temperatures exceeded 40°C, there wasn’t one single day when the maximum temperature [06-18] exceeded or equalled 30°C. Not many people know that😉
Courtesy Copernicus- the picture that caused all the fuss
Just a quick look back at the heatwave of July 2023 across the Mediterranean. There was a great deal of interest in this taken by the media in the UKUKThe United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland., particularly the BBCBBCThe British Broadcasting Corporation (BBC) is the national broadcaster of the United Kingdom, based at Broadcasting House in London. It is the world's oldest national broadcaster, and the largest broadcaster in the world by number of employees, employing over 22,000 staff in total, of whom approximately 19,000 are in public-sector broadcasting.. As far as I can see it was in my opinion, and that’s what this blog is all about, was sparked off initially by some overzealous reporting by the new (to me) Rome correspondent who was interviewing a selection of British tourists in the centre of Rome in the middle of a hot sunny day. I think this was in reaction to a warning from METEOAMMeteoAMThe Italian Meteorological Service is an organizational unit of the Italian Air Force (Servizio Meteorologico dell'Aeronautica Militare) and the national meteorological service in Italy. The weather forecasts and other services serve both the armed forces and the general public. of a severe heatwave dubbed Cerberus on the 13th. If you’ve ever been to Italy or abroad you’ll realise it’s usually a good idea to hide from the sun at this time of the day😉 As far as I can ascertain from observational data there was a short 3 day heatwave (see thermograph below) at Rome’s airport. The trouble with observational data from Italy, as is the case in the UK, you can only access a subset of it, and unfortunately Rome has only one SYNOPSYNOPSYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting weather observations made by manned and automated weather stations. SYNOP reports are typically mad hourly and consist of groups of numbers (and slashes where data is not available) describing general weather information, such as the temperature, barometric pressure and visibility at a weather station. station situated at the airport on the coast. Because of the HIEUHIUrban Heat Island (UHI) is an urban area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces I’m sure it was much warmer in the centre of Rome. Not only is there a shortage of observational data for many countries, I challenge you to find any up to date LTALTALong Term Average. This is usually defined as a 30 year period by the WMO. climate data for any of them either. What I mean here by up to date is the LTA for 1991-2020 and not that for 1971-2000 that I have for many stations. You would have thought in these days of “global boiling” the latest climate station for all member countries would be available on the WMOWMOThe World Meteorological Organisation is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics. website – no it isn’t – and if it wasn’t for Wikipedia, and some nifty parsing, I wouldn’t have collected over 800 LTA records across the world as I have. I’ve been watching and examining heatwaves closely across the UK and Europe since I retired from the Met OfficeUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy in 2011. There are no rules as to what constitutes a heatwave, and therein lies the problem. The UK have one set of rules and every other country has another, and that’s why I argued, mainly to myself because few people read what my views are or give a damn about them either, that instead of a rigid threshold for summer months of X°C for a region, as the UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy do, a “heatwave day” should be defined on the anomaly of the maximum temperature for each individual station. Over the years I’ve developed software and I usually default to an anomaly of 6°C above the LTA. Personally I think this is much too low for a severe heatwave, and probably should be ~+10°C. The thermograph for Seville shows the extent of the heatwave there using this 6°C rule. Three distinct heatwave days up to the 28th. These anomalies are calculated using the 1981-2010 LTA and not the much colder LTA of 1971-2000.
Seville 1981-2010 LTA
These thermographs for Rome, Decimomannu and Palermo use the 1971-2000 LTA. and because they anomalies calculated using this slightly colder LTA, the anomalies are much warmer than if I had the ones for 1991-2020. I’ve emailed METEOAM to see if I can obtain them, but am not hopeful I will be able to source the latest climate data. I shouldn’t need to do this, or rely on Wikipedia to supply them, this basic climatological data should be available from the WMO. That aside the three thermographs do highlight a series of heatwave days, with many as 15 at Decimomannu in Sardinia with an extreme maximum of 46.8°C.
I hope I’ve explained the importance of using the latest LTA for all stations to get an unbiased picture of July’s heatwave. The map below of total heatwave days shows the number of days with a maximum temperature anomaly of 6°C or higher. There’s no doubt that it was hot across a large of southeastern Europe using the +6°C threshold, particularly across parts of northern Algeria and Tunisia. There are what looks like spuriously high anomalies scattered around these are probably caused by out-of-date LTA.
Number of days with a maximum temperature [06-18] >=+6°C
If you look at the next chart this shows the total number of days with anomalies of +10°C or more, and what I maintain are severe heatwave days. Heatwaves in the UK must last at least three consecutive days or more before they can be officially labelled a heatwave, many of the sites in the chart below away from North Africa have one or two, and even if they have more they may not be consecutive.
Number of days with a maximum temperature [06-18] >=+10°C
Looking at reanalysis gridded temperatures and anomalies up to the 26th reveal what I think was really going on. The core of the heat was across the north of Algeria and Tunisia, occasionally some of that very hot air escaped transferring northwards from Africa to affect parts of Sardinia, Sicily, southern Italy, western Greece and the Balkans, and because SSTSSTSea Surface Temperatures temperatures in the Mediterranean were at record levels during July, the sea didn’t cool the air at the surface as much as it could. The other thing is the media got a hold of this story and ran with it, this was easy to do, because they already had stories about heatwaves in the southern states of America and China, and as the month went on wildfires broke out, and it was also announced that July was very likely to be the record hottest month – a perfect combination for catastrophising the whole thing🥵. For the record heatwaves don’t cause wildfires people do.
The surge in SSTSSTSea Surface Temperatures that began in June has gradually been subsiding since the start of July, and now we’re starting to see some blue negative anomalies appear around the British Isles at last. What triggered this surge in SST’s is anyone’s guess. Perhaps a giant hydrothermal vent briefly opened on the mid-Atlantic ridge in the North Atlantic and spewed out an enormous amount of super-critically heated water for a couple of days? It may sound totally wacky, which it probably is, but there have been a number of hotspots that suddenly appear and disappear just as quickly in the last 10 years that I’ve been watching SST across the globe.
SST anomalies may have been falling across the Atlantic but they are still at record high level in the Mediterranean sea, particularly at the western end along the coast of north Africa.
The daily mean CETCETCentral England Temperature so far for this year (8 July) has finally caught up with last years, the warmest year on record in central England, but at this point 2023 is still only the 6th warmest, and both 2022 and 2023 both trail 2007. It’s noticeable that it was at this time last year that the mean temperatures accelerated, no doubt with the help of the hottest day in the series.
I resurrected from the archives, and reworked one of my old viewers in my Daily CETCETCentral England Temperature application this morning. It can show means, anomalies, extremes, deciles, quintiles and centiles of weekly temperature since 1772 in a heat map style data grid. It looks like I’ve just commenced the 3,606th week of my life, and that image shows all of them.
There’s been a massive fall of in Antarctic sea ice this season. I decided to emulate a graph I saw on Twitter that overlays a daily line series for each year since 1978 and then highlight specific series, red for 2023, blue for 2022, and green for 2016, the year of the previously lowest daily anomaly from the 1981-2010 LTALTALong Term Average. This is usually defined as a 30 year period by the WMO.. The total for the 5th of July is just 12.332 million square kilometres, that’s just 81.6% of the LTA for that date, and around 1.8 million square kilometres lower than last year the previous lowest.
Below is another graph you don’t often see and that’s total global sea ice extent from both the Arctic and Antarctic combined. There’s a very noticeable year-on-year decline in Arctic sea ice extent in the world.
