Autumn 2024 was rather an anticyclonic affair at times, particularly from late October to mid November, punctuated by cyclonic spells through October, and two named storms, Ashley on the 20th of October and Bert, between the 23rd and the 25th of November. It’s hard to beleive there is only one 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).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 analysis chart this autumn, from the whole 91, completely free of fronts of some kind around 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..
I thought that I’d look back at the three month outlook for autumn 2024 [SONSONMeteorological Autumn - September, October and November] issued 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 on the 27 August. The outlook is split into three distinct areas, temperature, precipitation and wind speed. It’s relatively easy to assess how accurate the outlook was for temperature and precipitation, but not so for wind because the UKMO don’t issue monthly gridded mean wind speed data. They must have this data because the three month outlook itself contain three month anomaly charts for wind speed. The one climate statistic that they did omit is sunshine, important not only summer, but also in autumn and winter, as this gloomy November highlighted only too well. Here’s a table of climate statistics 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 the three months that make up meteorological autumn and anomalies for temperature, precipitation and sunshine.
How accurate was the forecast of temperatures?
The outlook stated that there was a 40% chance of it being a warm autumn, with a fifty-fifty chance of near average temperatures. In the end, the mean temperature for the three months that make up meteorological autumn was +0.3°C above the 1991-2020 long-term average, so it was only marginally warmer. WRONG, autumn was not noticeably warmer than average, although they were right about ‘cool spells’ later in the season, but cold spells towards the end of autumn are far from uncommon.😉
How accurate was the forecast of precipitation?
The outlook stated that there was a 35% chance of autumn being wet, with a 55% of it being near average. In the end precipitation in autumn 2024 ended up 89% of the long-term average. So a drier, rather than a wetter autumn. Despite flooding from storm Bert, the first half of November was very dry across the whole country, WRONG.
How accurate was the forecast of mean wind speed?
The outlook stated that there was a 35% chance of autumn being windier than average, with an increased risk of stormy conditions. As I said earlier, there’s not an easy way of measuring the accuracy of this one. There were three named storms during autumn, one of them named by the KNMI, the other by Met EireannMet ÉireannMet Éireann, the Irish National Meteorological Service, is the leading provider of weather information and related services for Ireland.. The first half of November was anticyclonic which would have reduced the mean speed for the whole of autumn a fair bit. UNDECIDED.
The mean temperature during Autumn 2024 in central England was 10.9°C, which was +0.11°C above the 1`991-2020 LTALTALong Term Average. This is usually defined as a 30 year period by the WMO., making it the joint 21st mildest since 1659 in the series. Autumn 2024 also set three new daytime maxima (red stars) and one nighttime minimum temperature (blue star). All three months had a cold spell, the most significant occurring from the 19th to 22nd of November. Autumns in central England have been gradually warming by around 0.12°C per decade since 1878.
Meteorological Autumn 2023 has seen some quite varied weather types, predominantly anticyclonic until mid October and then full on cyclonic. It also contained four named storms, some of which were more deserving than others for being named. I can’t even remember them all, only Ciaran and Debi stick out. Zonality also did a couple of about faces during October and again towards the end of November.
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.
Autumn 1959 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. & 500 hPahPaA Hectopascal is the SI unit of pressure and identical to the Millibar gph
I can already see a few similarities in the first week of September with the memorable September of 1959. September 1959 had the third longest anticyclonic spell in the whole 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. series that began in 1871. The heatwave in the first week of September 2023 looks poised to break a number of CETCETCentral England Temperature record maximum temperatures that were set in 1959. In 1959 as well as possible heatwave conditions occurring between the 7th and 12th of September in central England, a second warm spell occurred between the 3rd and 7th of October. It will be interesting to see just how anticyclonic September 2023 proves to be, and if November turns out to be as cyclonic as that of 1959.
Autumn 1959 [SONSONMeteorological Autumn - September, October and November] Daily Central England TemperaturesAutumn 1959 [SON] Objective LWTSeptember 1884-2022 Ranked Highest Mean Maximum Temperature
Dear Diary, The days of air frostair frostAn air frost occurs when the temperature of the air falls below 0.0°C and ground frost were well down on their respective LTALTALong Term Average. This is usually defined as a 30 year period by the WMO. for all regions, thanks to the very mild weather. I would have like to have added a colour contoured map but 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 don’t seem to generate them anymore for frost. Still plenty of sites still to report their first frost, some of them inland as well. My 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. records are never guaranteed to be 100% complete, so I may have missed the odd one because either the value or the whole observation 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). was missing. I could now, at least 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. that is, generate totals from the 21-09 UTC extremes now that they are finally being included.
Dear Diary, Unsurprisingly, Autumn 2022 [SONSONMeteorological Autumn - September, October and November] ended up the third warmest since 1659 in Central England, with a mean temperature of 12.4°C, which was +2.4°C above the 1659-2020 LTALTALong Term Average. This is usually defined as a 30 year period by the WMO.. There were only a few colder than average spells with warm spells dominating for long periods.
Here are some of the wettest places 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. reports this meteorological Autumn so far. They may not have seen as much rainfall as the likes of Capel Curig or Tulloch Bridge, but their POAPOAPercentage Of Average put them in the top ten wettest places in the whole of 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.. Despite the local flooding in places, I reckon this wet Autumn has got to be looked upon as a good thing to replenish rivers and aquifers, but as you can see from the accumulations plotted in the map not all places have been as wet as these particular four sites. With a couple of weeks still left to go this could end up as one of the wettest Autumns on record.
