Surprisingly, October ended up a rather average kind of month as far as sunshine, precipitation and temperature were concerned for 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. as whole. Regionally, the northwest was drier than average, and the northeast sunnier than average. Mean temperature anomalies across the nation, which were slightly above the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO., were within 0.3°C of each other. As Greavies would remark, it’s a funny old game Saint😜
Christmas Day 12 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). 1979-2023
This post is more of a reminder to myself about an application I wrote to display a grid of charts it downloads from Wetterzentrale. You can choose to display CFS, ERAERAERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera). or 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. reanalysis charts either as charts of isobars overlaid over colour filled contours of 500 hPahPaA Hectopascal is the SI unit of pressure and identical to the Millibar heights, or as charts of isolines of 850 hPa geopotential heights, overlaid on colour filled contours of 850 hPa temperature. I think it produces a pretty useful grid of charts to view a month, or a season, but in truth I haven’t used it that much in the last 12 years. The example above displays surface pressure charts for Christmas day.
Winter [DJFDJFMeteorological Winter comprising the months of December, January & February] 1962-63
The grid of images above, is for daily 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. and daily 500 hPa geopotential heights for each day of the infamous winter of 1962-63.
The other innovative thing that I added to the application, was a colour analyser (above image). This does a lookup on the colour of each pixel across the map of the British Isles in the downloaded image, and calculates an overall average which it uses to plot a graph and fill a table with the daily 850 hPa temperature or the 500 hPa geopotential height. A crude but quite effect way of gauging just how warm or cold it is on any given day. There are problems with the app, but out of my control, in that Wetterzentrale for some years, use a slightly different resolution and size for their images. I could fix it but it’s fiddly. They also seem now not to load the ERA reanalysis images on their server. Who knows for how much longer they’ll maintain the CFS and NOAA images, it would be a real loss if this went.
A month at first glance dominated by colder than average temperatures. Yet another cold month across Iceland, with what’s fast becoming the normal NW-SE temperature gradient across the British Isles.
Mean temperatures across the British Isles were close to the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO.. Much of the North Atlantic was warm (+3C) south of 55N, but a band of colder temperatures extended from Baffin Island (-5C) in the west to southern Scandinavia (-1C) in the east. Meanwhile the north of Scandinavia was warm (+3C), likewise SE Europe around Bulgaria was also very warm (+4C).
I’ve redesigned how I visualise moving averages in my Daily CETCETCentral England Temperature program to generate a user definable moving average graph of daily CET values since 1772, this ended up being something of a job because now I dynamically plot over 250 annual ‘silver’ coloured line series, one for each year, as a backdrop. Over this backdrop I plot a 30 day moving mean for the year (dashed black), along with its corresponding +1/-1 standard deviations (dashed red and blue lines). On top of that I plot the coldest (bold blue) and the warmest (bold red) 30 day period ending 13th of April. Finally, I plot the 30 day moving average for the last 365 days (bold black with yellow outline), and at the same time I list the latest values in a ranked table on the left. With it, I make the latest 30 day mean temperature 10.57°C for the 13th of April, that’s the warmest 30 day period for that date in the series since 1772, and 3.53°C above the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO. for 1772-2023. As you can see n the graph and the table this is significantly higher that the previous warmest of 9.79°C in 2017. Hopefully all this new code is producing accurate results 😉
The exceptional heatwave across Belarus, Ukraine & E Russia continued this lunchtime, with anomalies as high as +19°C, the highest I’ve seen. Juxtaposed with the very cold air across Finland, Sweden and northern Norway.
The curious thing in March was that although Atlantic SSTSSTSea Surface Temperatures were at record high levels, the air above it (in the central Atlantic at least) was 2 degrees colder than average.
For people who can’t get their heads around anomalies I’ve made a slight variation on just a simple bar chart of anomalies. The twist is that it now displays both daily temperatures and anomalies, temperatures on the left Y axis and anomalies on the right Y axis. My 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.NWPNWPNumerical weather prediction uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. application downloads forecast data the BBC use in their own weather app, and parses the HTML and extracts hourly and daily forecast values for each site. I’ve kept the same scale for the extremes in each charts Y axis for each site I display in the grid to aid comparison. So you can now quickly see at a glance the forecast temperature and how it compares with the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO..
2024 saw an exceptionally mild February across much of Europe, the warmth centred across the eastern Alps (+7°C). It was a little colder than average across to the northwest of Iceland (-2°C), which help produce a tight SE-NW temperature gradient across the IONAIONAIslands Of North Atlantic.
Yes I know there's an island called Iona, but this is so I don't have to use the term 'British Isles' when referring to the whole of Ireland and the UK. which and was evident for much of the month. It wasn’t just Europe that was very mild, much of North America, away from the extreme west, was also anomalously warm (+6°C) during February.
Basically a wet and very mild February across the south and southeast of England, but colder and drier further north and west. Dull across England and Wales but brighter further north and east further north and west particularly the northeast of Scotland.
Using gridded monthly climate data from 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 and a simple linear trend for over the last thirty year, it’s easy to see that annually 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. as a whole has become warmer by 0.29°C per decade, wetter by 26 mm per decade and sunnier by 30 hours per decade. These three charts are twelve month moving averages from 1970, with a thirty year linear trend from 1995 to gauge the change overlaid.
Courtesy 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 StrategyMean Temperature Anomaly I make January just slightly colder than average across the whole of 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..Extreme maximum and minimum A month of sharp contrasts in extreme temperature.Number of Air Frosts and Ice Days A fairly even distribution of air frosts across the country.Close to average generally, but much wetter across the north of England and drier further west and far north. I’m skeptical of no returns in snow so take many of these values with a pinch of salt.
Sunday the 28th of January 2024 was an interesting day across the Northwest of Scotland. The manual maximum temperature reading of 19.9°C at Achfary in Sutherland caught 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 out completely, it was only yesterday that they were predicting the highest temperature today would be 16°C in the north of Wales, with a high of only 14°C forecast for the north of Scotland. It seems they have some serious problems forecasting temperatures in 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. conditions like these in their mesoscale model. Provisionally, the 19.9°C at Achfary exceeded the old record of 18.3°C by a whopping 1.6°C.
Interestingly, Achfary now holds two maximum 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. monthly records, one for December and now one for JanuaryTweets from the UKMO on the 28th & 29th January 2024Thermograph for Loch Glascarnoch A diurnal range of 19.8°C from a max of 17.4°C to a min of -2.4°C.Comparison of the maximum anomalies on Sunday [06-18] with the minimum ones on Sunday night [18-06]
There was also a strange area of moderate/heavy rain which developed across central Scotland on the radar during the early afternoon, well ahead of the cold front that was just coming into the Western Isles at 1455 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).. In StrathpefferStrathpefferStrathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469. it produced large spots of rain from 1330 UTC, and a spell of moderate rain just before 15 UTC. The rain seemed to be falling out of blue sky at times, and even at 15 UTC there was only seven oktas of thin CICSCICSA combination of Cirrus Cirrostratus cloud and some thin lenticular ACACAltocumulus clouds are generally associated with settled weather and will normally appear white or grey with shading.
Height of base: 7,000 - 18,000 ft
Shape: Bands or areas of individual cells
Latin: altum - height; cumulus - heap
Altocumulus clouds are small mid-level layers or patches of clouds, called cloudlets, which most commonly exist in the shape of rounded clumps. There are many varieties of altocumulus, however, meaning they can appear in a range of shapes. Altocumulus are made up of a mix of ice and water, giving them a slightly more ethereal appearance than the big and fluffy lower level cumulus. in the sky. The wind in the tops of the trees must have been close to force six from 270° so all I can assume it was being blown a very long way. The only thing I can think that caused it was an upper cold front running ahead and parallel to the cold front.
Saharan dust producing this peachy coloured high level CICS Courtesy of @HighlandWeather
The waters around IONAIONAIslands Of North Atlantic.
Yes I know there's an island called Iona, but this is so I don't have to use the term 'British Isles' when referring to the whole of Ireland and the UK. are all still well above average for early January. In fact the southern North Sea is +1.7°C above the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO., and has been for some considerable time. It’s no wonder when we do get a cold Arctic northerly or a continental easterly, why temperatures are even more attenuated by the SSTSSTSea Surface Temperatures than they usually are.
A thirty year linear trend reveals that 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. has become steadily warmer, wetter and sunnier in the last 30 years. The latest 12 month average at the end of December shows that the UK is currently running close to average for sunshine at 102%, but 111% for precipitation, whilst temperatures for the last 12 months are +0.81°C above the 1991-2020 LTALTALong Term Average. This is usually defined as a 30 year period by the WMO..
The curious thing is in a record warm world why has it been so cold in the last month in our bit of it? Answers on a postcard to the editor if you please.
A perfect example this month of how gridded climate data, even when interpolated onto a 1 km x 1 km fine grid, can make some places drier and warmer that they really where.
Wettest Octobers 1836-2023 Rather Surprisingly, only E Scotland had a record wet month in the gridded regional data.Oct 2023 Rainfall POAPOAPercentage Of Average I’m not convinced with the contouring. I’ve never looked at it in detail before It’s neither caught the 228% in StrathpefferStrathpefferStrathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469. (dark blue) or the 219% at Tain, and seems to have completely missed the 408% at WattishamThe interpolation & smoothing used by 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 producing its 1 x 1 km gridded data seems to have remove the wettest spots such as Wattisham completelyOctober 2023 Mean temperature anomalies Strange, several stations with anomalies of -0.5°C or lower across the Scotland not registering as a blue contour fill including Baltasound“though areas further north were generally closer to average”. Not quite accurate statement for some places across NENENorth East Scotland, and that includes Baltasound in Shetland, mean anomalies were 1°C below the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO.
Another very warm month across the Arctic. Warm in S Europe & NENENorth East America, but rather cold across Central N America and Scandinavia. North-south temperature gradient very evident across 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..
Just a quick note to make a note about how late an Autumn it’s been in 2023. Its now past mid October, and many trees here in StrathpefferStrathpefferStrathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469. are still have more green leaves than they do brown, and although the Service and Birch tree have lost most of their leaves, others have not. I witnessed late, even very late Autumns in Devon over the years, but not here in Scotland since we returned five years ago. Why is Autumn late? Simple enough, summer was pushed into September and early October by a rather cold mid-summer as these anomaly charts show. The numbers in the pink boxes by the way are the mean anomalies for the gridded temperatures for the whole map, the graph is for temperatures at the grid point 57.5N 5W, the closest to home. It does make you wonder if meteorological summer should now be a four month period rather than a three which also includes September, whilst Autumn should now include December. By the way the title of that graph should read Mean Temperatures and not anomalies and another thing to put right.
One country in Europe that’s bucked the trend of a warm summer in 2023 was Iceland. I’ve noticed this in the monthly anomaly charts for mean temperature that I produce, so I decided to spruce up my chart grid viewer to see if I was right in my assumption, and as you can see in this chart of weekly mean anomalies I was. What caused it is may have been persistent high pressure across the Greenland ice cap to the northwest of Iceland, and a shift southward of the Icelandic low, which in turn allowed more days of northerly or north-westerly flows and hence the lower than average temperatures.
It’s not easy to verify these findings because even the Icelandic 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 site offers no real clues to how they categorised this summer’s temperatures. If you’re by any chance reading this in Iceland, please let me know how you found it😉
I was watching the Deep Dive video produced by 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, and presented so well by Alex Deakin about the weather in September 2023 on Youtube as you do. He showed two anomaly charts for 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., one for the first half of September and the other for the second half that showed how anomaly charts for the whole month can sometimes be misleading. In this case it was how the remarkable warm spell in the first half of the month contrasted with the more mobile second half. The resulting anomaly chart for the whole of the September cancelled out the anticyclonic SE’ly in the first half that brought all the high temperatures.
The mean temperature for 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. for September 2023 in the gridded series was 15.2°C which equalled that of 2006.
