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.
Sep 2024 – Temp Anomalies Read More »
Four days of thunderstorms, heavy showers and rain across the south all due to an upper cold pool that migrated westward.
20-23 September – Wet spell Read More »
I noticed recently that the UKMOUKMO The 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 started to publish and maintain on their website, data files of daily mean maximum and minimum temperatures from the stations that they have used to calculate the composite Central England Temperatures since 1878. I had given up hope of ever seeing this data, which gives a better insight on the machinations the UKMO go through to produce the series each day. What would Philip Eden have given to access this CETCET Central England Temperature data! 😜 As you can see from the above screen shot above I’ve added a new viewer to my Daily CET application to download, parse and display the data in tabular form and as plotted charts.
At the moment the CET series uses temperatures from the following stations:
Each of these site has a buddy site, so if it fails to report, the temperature from the other site can be used in its place. This happens a lot more frequently that I ever realised. The data files do include a file of eight boolean flags to identify which site were used for which day. The table below is for the CET values up to the 4 September 2024. I’ve highlighted the sites that are being used in the table in bold, and used grey text for those that aren’t. The provisional daily CET is in the 2nd from right column, and the difference column on the right, is the difference between the provisional mean and the one calculated from the raw data from stations being used. The difference is probably the adjustment applied to each stations temperature for the effects of urbanisation.
The table below is from 2004, and I think marks the point when Stonyhurst and Pershore replaced Squires Gate/Ringway and Malvern in the series. Whoever in the Met OfficeUKMO The 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 thought temperatures from a coastal site like Blackpool was a good site to represent central England beats me, although that might be down to how Manley constructed his original monthly series. I think the Stonyhurst temperature record is second only to Oxford in England in length, and had been used for many years before this.
The latest sites all have their own peculiarities as you can see from the graph below of 30 day average daily maximum temperatures. Stonyhurst is usually the coldest of the latest three sites being used to calculate daily CET values, with Pershore usually the warmest, with Rothamsted usually trailing a little behind Pershore. All this is obviously weather dependent. So the composite CET for the warmest day in the whole CET series in July 2022 ends up being in no mans land temperature wise.
Similarly in this graph of 30 day average daily minimum temperatures from 2010, Stonyhurst is usually coldest, although the three minimum series are more closely bound than the maximum. You can see that in the cold December of 2010, Pershore is fractionally colder than Stonyhurst for a while.
The table below shows how the CET series has changed at times in recent years, and how the buddy system comes into play when temperature data goes missing.
Central England Temperatures – Raw station data Read More »
MSLPMSLP Mean 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. was below average for much of the summer [JJAJJA Meteorological Summer comprising the months June, July & August] with a strong mobile W or SW flow with an above average GIGI Gale Index. Brief anticyclonic interludes that got briefer as the summer went on. The NW flow in June backed into a SW’ly from the middle of July.
Summer 2024 – Objective LWT Read More »
After a break from being the warmest month on record in July, the ERA5ERA ERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera). series is back on track. This months anomaly of +0.712°C was again the warmest on record, but just a smidgeon (0.002°C) warmer than that of August 2023 (0.71°C).
It may be another record month, but the 12 month moving average has flattened out now, after sharply rising since mid 2022. As you would expect 2023 and 2024 are also neck and neck as the highest daily anomaly on record too. It looks to me that the global temperatures we’ve experienced over the last 18 months could become the new norm despite an imminent La NinaLa Niña La 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.".
August 2024 – Global Temperatures Read More »
A lot of strange goings on in mean temperature anomalies for August across this part of the northern hemisphere. One of them was a belt of colder than average temperatures that extended from the central Asia southwest across Pakistan, and then on westward across sub Saharan Africa. Another was the more intense pockets of cold air across British Columbia and Iceland. The North Atlantic was a little colder than average north of 55N, but much warmer than that to the south (+2C), the UKUK The 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. again ending up sandwiched again in a NW-SE temperature gradient.
August 2024 – Temperature Read More »
Anomalies of -15 hPahPa A Hectopascal is the SI unit of pressure and identical to the Millibar to the SE of Iceland displaced the usually shallower Icelandic low east to produce a broad SW’ly flow across the UKUK The 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. and Ireland during August. The semi-permanent Azores high remained with pressure a little higher (+2 hpa) than average enhancing the flow.
August 2024 – MSLP Read More »
The Met OfficeUKMO The 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 just introduced a new feature to their forecasts you find on their weather app or on their website. As well as including the probable daily maximum and minimum temperatures for the next seven days, they also now include values for the highest and lowest possible temperatures for that day too. The BBCBBC The 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. do the same thing in their forecasts, but as far as I know, it remains hidden and unused in the HTML.
Personally, I can’t see what benefit this ‘fudge factor’ is to any forecast, other than adding a degree (pardon the pun) of uncertainty to the end user – which temperature is it going to be today or tonight, probable or possible? It also makes a bit of a nonsense of having fixed hourly temperatures, which remain presumably of the ‘probable’ variety.
I’ve been doing some verification work on forecast three hourly temperatures over the past year, and I’ve found their forecast temperatures vary dramatically from the actual reported values beyond T+36. It’s a little bit early but I’ve not noticed any significant improvement since I started using the new beta data.
All I can say is if that people do complain to them about the accuracy of their temperature forecasts in the future, this will be a very neat way of getting them out of a fix. 🤨
A new feature in Met Office forecasts Read More »
I make the summer of 2024 [JJAJJA Meteorological Summer comprising the months June, July & August] the coldest since 2015, with a mean temperature of 15.77°C, which was 0.27°C lower than the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO..
Summer 2024 – Central England Temperatures Read More »
Not much to say about summer [JJAJJA Meteorological Summer comprising the months June, July & August] other than it ended up a very average summer. That was because the cooler, cloudier, wetter conditions in the northwest, were almost perfectly cancelled out by the drier, sunnier and warmer weather in the east and southeast.
Summer 2024 – weather summary Read More »
The summer index [JJAJJA Meteorological Summer comprising the months June, July & August] in the UKUK The 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 2024 came in at 11, which was almost the same as last summer. June had the lowest combined monthly index for temperature, precipitation and sunshine of 6 [3,1,2], whilst August bolstered the summer up with an index of 9 [5,2,2].
Regionally East Anglia, the southeast and central southern England and eastern Scotland had the highest summer index of 24. The lowest index, which I can vouch for, was -23 in the north of Scotland.
Summer Index – 2024 Read More »
A cold pool has developed in the last six weeks off the coast off the coast of northwest Ireland and western Scotland. It’s incongruous, because at the moment the SSTSST Sea Surface Temperatures of the North Atlantic are at the second highest level since 1981, and possibly many hundreds of years before this. It’s expanded & consolidated a little more during the last week, but what’s behind it? Answers on a postcard to the usual address.😉
What’s happening to SST in the northeast Atlantic? Read More »
I’ve been putting quite a lot of effort into a program I’ve developed that parses forecast data from the Met OfficeUKMO The 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 weather app. I needed to do this because the UKMOUKMO The 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 just updated it to a new beta version, and in so doing have reworked all their HTML, which scuppered my old application which I developed some years ago. As far as I know there is no API that I call to access the raw forecast data with, so it’s all down to downloading and parsing a lot of HTML to extract the forecast data myself. It’s not been easy, and I’m not getting any younger, so at times it’s been a real struggle. Anyway I’ve completed most of the work now, and all that’s left is to update the numerous viewers that I use to display the forecast data in various tables, graphs and maps.
The only new feature I’ve seen that’s different in the beta version when compared to the old version is that as well as including a ‘likely’ maximum and minimum, the Met Office now also include a ‘possible’ maximum and minimum. Don’t ask me why, but it mimics what the BBCBBC The 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. do in their app.
The animated GIF is generated from a viewer that builds a bitmap image from all the available three hour forecast data for the coming week. I’ve also added maximum and minimum daily anomalies to it, as well as including an icon to show the phase of the moon and when it rises and sets.
I have a verification form which compares forecast values with SYNOPSYNOP SYNOP (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. At the moment this only works for extreme temperatures, but there is no reason why this couldn’t work with wind speed, visibility and weather.
So much to do, and so little time😢
The Met Office Weather App Read More »
Here are some random images, tables and animations that I posted regarding Storm Lilian to my Twitter account @xmetman. Nothing particularly devastating about the winds or the rain from the storm itself, which the Met OfficeUKMO The 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 should really have never named. It was gone in a flash, and although there were gusts in excess of 70 mph on the Lancashire coast, only eight SYNOPSYNOP SYNOP (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. stations recorded a gale. Gale Index wise the storm didn’t register above the 200 mark because of its size, with the extratropical cyclone that had been Hurricane Ernesto scoring much higher earlier in the week. I should have written a piece about Ernesto, but when you have so few followers as I have, I thought what’s the point 😪
23 Aug 2024 – Storm Lilian Read More »
All Images courtesy of BBCBBC The 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. Weather Watchers
A lovely sunset across the northeast of Scotland this Monday, which I managed to completely miss despite having a camera with me at the time, so I deferred to these excellent images from the BBC Weather Watchers website.
12 August 2024 – Sunset Read More »
The central Pacific continues to cool, if rather hesitatingly over the last month.
Here’s the latest ENSOENSO El Niño–Southern Oscillation is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña. forecast from the IRI.
A monthly summary of the status of El NiñoEl Niño El 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, La NiñaLa Niña La 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.", and the Southern Oscillation, or ENSO, based on the NINO3.4 index (120-170W, 5S-5N)
As of mid-July 2024, ENSO-neutral conditions persist in the western equatorial Pacific, and oceanic and atmospheric indicators also align with ENSO-neutral state. The IRI ENSO prediction plume forecast ENSO-neutral for Jul-Sep, and Aug-Oct, 2024. La Niña becomes the most probable category in Sep-Nov, 2024 through Dec-Feb, 2025, while for Jan-Mar, 2025 ENSO-neutral conditions become dominant (50% chance), and remain so during Feb-Apr, and Mar-May, 2025.
Similar to the most recent official CPCCPC The Climate Prediction Center is a United States federal agency that is one of the National Centers for Environmental Prediction, which are a part of the National Oceanic and Atmospheric Administration's National Weather Service. The CPC is where meteorologists and oceanographers review climate and weather observations and data along with model results; assess their meaning, significance, and current status; and likely future climate impacts. ENSO Outlook (issued on July 11, 2024), the objective IRI model-based ENSO outlook forecasts indicate ENSO-neutral conditions for Jul-Sep 2024. However, there is a notable difference between the probability numbers in the early-month CPC and mid-month IRI ENSO forecasts. The CPC ENSO forecasts predict a 70% chance of La Niña onset in Aug-Oct 2024, which then persists with increasing probabilities reaching into the range from 66% to 81% during the boreal fall and winter seasons. In contrast, the objective IRI ENSO forecasts show a late onset of La Niña conditions in the equatorial Pacific (49% chance in Sep-Nov 2024), with persistence into the fall and early winter, though with very low probabilities ranging from 52% to 48%. The forecasts then show a return to ENSO-neutral conditions in Jan-Mar 2025, and remain dominant for the rest of the forecasts period. The low probability numbers reflect a high level of uncertainty in the forecasts, due to the relatively low skill of seasonal forecast models at this time of year. Therefore, these ENSO forecasts should be interpreted with caution.
The 13 month consecutive record breaking streak in the ERA5ERA ERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera). global temperature series has come to an end. The July anomaly of +0.68°C, although high, was lower than the +0.724°C of July 2023. The 12 month moving averages are also starting to show a lessening in the steepness of the rapid increase since the start of 2023. I’ve seen little mention of this news in the media which doesn’t surprise me that much. 😉
Despite being knocked off the top spot for warmest month in July, the daily global temperature for the 7th of August is still setting new records. It’s vying with 2023 for warmest and currently stands at +1.597°C above the pre-industrial LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO..
13 month streak comes to an end Read More »
Arctic sea ice extent was the third lowest for this date at 77.8% of the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., behind 2020 & 2019, and down 5.6% on the same date last year.
Antarctic sea ice extent was the second lowest since 1978 for this date at 89.2% of the LTA, just behind & tracking 2023, with ~8 weeks to go before maximum which was early last year.
1 Aug 2024 – Latest polar sea ice extent Read More »
July 2024 was a very zonal month, and cyclonic at times, with below average MSLPMSLP Mean 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., but a little more anticyclonic towards the end. It looks like I’m going to have to search for missing charts on the 10th and 11th. Sunday the 28th looks a rare day when the UKMOUKMO The 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 couldn’t find a single frontal structure or trough near IONAIONA Islands 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..
Mean temperatures across the British Isles were close to the LTALTA Long 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).
July 2024 – Temperature Anomalies Read More »
Pressure was lower (-3 hPahPa A Hectopascal is the SI unit of pressure and identical to the Millibar) close to the Azores during July, with higher than average pressure to the west this displaced the usual Azores high further west in the North Atlantic. This, combined with much lower than average across Greenland and Iceland, resulted in a fairly strong mean zonal W’SW flow across the Atlantic for the time of year, running from Canada to the Baltic across the British Isles.
Despite central England temperature series being a composite temperature from three separate sites, it’s still possible to use the UKMOUKMO The 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 25°C heatwave temperature as the threshold to calculate a heatwave day in Central England, and thereby calculate the number of three day consecutive days that have occurred there since 1878. I added this functionality to my Daily CETCET Central England Temperature application a number of years ago, and have recently added a second method of using the maximum anomaly to do it, rather than by using a fixed temperature. At the same time I gave it all a bit of a spring clean, hopefully it’s still accurate. 🤞
The program allows you to adjust the threshold from 25°C to 30°C, and the anomaly from +6°C to +10°C, it also allows you to change the number of consecutive days from 3 to 7.
If you plot a bar chart for the number of heatwave days since 1878, as I’ve done with an accompanying 5 year centred average and linear trend, you’ll see that the number of days >=25°C has increased from 4.6 days to 10.8 days in the intervening 146 years.
The most number of distinct heatwaves (using the 25°C and three consecutive days or more rule) in a single year was six and occurred in both 1911 and 1995. The most number of heatwave days in any one year was 33, and occurred in 1976 and 1995.
The longest heatwave I found, using the 25°C and three consecutive days or more rule, was 16 days which occurred in the golden summer of 1976, between the 23rd of June and the 8th of July 1976 this was closely followed by the 15 day heatwave covering an almost identical period in 2018.
The results using anomalies are a horse of a different colour and a story for another day. Suffice it to say I used the 1878-2023 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. as a level playing field to produce the results in the table below. The year 1995 still ends up with most heatwave days of 32, and 1976 the longest run of anomalies of 6°C and higher of 16 days.
Heatwaves in Central England since 1878 Read More »
Below are some of the images that I posted on Twitter concerning the heavy rain and flooding from thunderstorms across parts of southern England on Thursday. Although the UKMOUKMO The 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 scored nul points with a yellow warning for thunderstorms on the previous day, the warning they issued for Thursday was fully justified 👍.
1 Aug 2024 – Thunderstorms Read More »
The first half of July was rather cold, but thanks to two warm spells in the second half of the month, the mean temperature for July ended up being 16.3°C, thats -0.5°C below the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO.. That makes two consecutive colder than average months, which happened as recently as 2023, when both July and August were colder than average.
