May 2024 – Mean Temperature Anomalies
May 2024 – Mean Temperature Anomalies Read More »
May 2024 – Weather Summary
May 2024 was a record warm month in Scotland. In the north of Scotland mean temperature were +3.5°C above the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., and beat the previous record set in 1889 by 1.6°C. 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 say the high mean temperatures were down to high overnight minimum temperatures, that may be true for the whole of 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., but not for northern Scotland where the mean maximum anomaly of +3.3°C was very similar to the mean minimum anomaly of+3.5°C.
May was also another rather dry month in NW Scotland with rainfall totals just 63% of the LTA. Although there were some very sunny days total sunshine for the month was just 85% of the LTA.
May 2024 – Weather Summary Read More »
Monday, 2 June 1975 – The day that snow stopped play
I’m guessing, but it looks like the snow that stopped play at Buxton was from heavy snow showers over high ground, enhanced by that trough close to Liverpool at 12 UTCUTC Coordinated 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).. I remember the day quite clearly because I was a window cleaner back then in Sheffield. Needless to say, I didn’t get many houses done that Monday. 😉
This PDFPDF Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992. of the day in question is courtesy of 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
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Scotland’s shires
I monitor the weather forecast for the Highland and Eilean Siar region of 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., so a map like this that delineates the exact area comes in handy when trying to decipher the forecast 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. Basically it comprises the whole of the Highland region plus the Western Isles. Even after being up here on and off for over 15 years, I still have a job trying to visualise the precise areas they are trying to describe. One thing I do know though is that just using terms such as ‘in the east’ or ‘in the west’ doesn’t help in an area as large and oddly shaped as this one is. Neither is using towns and cities such as Inverness and Nairn as reference points. Do you have any idea where Lochaber is? Or for that matter where Sutherland and Caithness are, and how far Ross-shire (or should that be Ross and Cromarty) extends? Shires in Scotland are a very complex subject, as this Wikipedia article explains.
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Jan-May 2024: Disparity in precipitation across Scotland
Just a couple of hyetographs so far this year to compare precipitation totals at Loch Glascarnoch in Wester Ross with those at Gogarbank Edinburgh further south. The difference is very marked, with only 87.7% of the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. in the north and 169% of the LTA in the south during the first five months of 2024. That large Edinburgh total is probably due in part to a couple of thundery days that occurred in April and May. Having said that, I’m sure that the tracks of the numerous lows and their frontal systems has much more to do with it.
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Spring 2024 – Warmest on record in Central England
I make the mean temperature for spring [MAMMAM Meteorological Spring comprising the months of March, April & May] 2024 in central England 10.6°C, that’s +1.38°C above the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., and the warmest spring since the series began back in 1659.
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May 2024 – Second warmest in Central England
I make the mean temperature for May 2024 14.1°C, that’s +2.2°C above the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., making it the second warmest May since 1659, but still well behind the 15.1°C of 1833.
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Recent uptick in UK Precipitation
There’s been a lot of talk about how climate change is resulting in wetter seasonal rainfall 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.. You’ve all heard the mantra “A warmer atmosphere is capable of holding more water vapour”, almost as cliched, but not quite as elegant as the definition of a jet stream being “A fast moving ribbon of air high up in the atmosphere”. Here are a few graphs of UK and regional 30 year moving averages that I’ve drawn from 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 UKPUKP UKP is a gridded datasets of UK regional precipitation. gridded climate data to illustrate what’s been going on since 1836.
I’ve added two linear trends to the annual UK precipitation graph, one for the 1865-1993 period and the second for the last 30 years from 1994 to 2023. You’ll immediately notice a dramatic increase in UK annual precipitation since 1980. You could argue that we’ve seen upticks like this before (1860-1885 and 1915-1930), and this is one is just the result of the natural variability of the climate as they were. I don’t think so though because this increase has been going on for over 40 years and shows no sign of running out of energy and linked with increases in global temperatures during the same period can’t be coincidental. The size of the linear trend suggests that annually the UK is getting wetter at the rate of almost exactly 1″ per decade, not a lot, but it’s the change in the rate that’s more important.
Winter [DJFDJF Meteorological Winter comprising the months of December, January & February] precipitation shows a similar increase from around 1995.
Summer [JJAJJA Meteorological Summer comprising the months June, July & August] rainfall is more dramatic still, with a steady decline in rainfall suddenly being reversed in the last 20 years.
Finally here’s a grid of monthly averages and trends for the UK. As you can see not all months are getting dramatically wetter. Some regions are showing little sign of getting wetter than they have been in the years up until 1993, January, April, November and December for example, whilst March and September have become a little drier in the last 30 years. I’ll leave you to make your minds up about the underlying reason for it. 😉
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First 20°C maximum in Central England keeps getting earlier
The first 20°C maximum in central England occurred on the 10th of May this year (2024), which is just about the average date for it to occur. In this ever warming world it’s gotten progressively earlier over the years. The linear trend (1878-2024) reveals that it occurred as late as the 20th of May back in 1878, but it’s now closer to happening three weeks earlier on the 28th of April. This is another new addition to my Daily CETCET Central England Temperature application.
First 20°C maximum in Central England keeps getting earlier Read More »
Eleventh consecutive warmest month globally
My DIYDIY Do It Yourself global temperature series was wrong once again in April. It predicted a tie in global temperatures with April 2016, but shock horror, 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). reports an anomaly of +0.67°C, which is well above the +0.529°C of 2016 making it the eleventh consecutive warmest month. 😲
Below is a graph of 12 month moving average global temperature anomalies since April 1994 from seven of the world’s leading global temperature series. None of them are as quick of the mark at reporting their results like the ECMWFECMWF The 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., but all show the recent surge that started at the beginning of 2023. The 30 year linear trend on the ERA5 series shows an increase of +0.24°C per decade over that time, and the warming trend that started in 1970 is starting to accelerate.
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April 2024 – Objective LWT
A fairly cyclonic start and end to April 2024 in the objective LWTLWT Lamb 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. indices, with an anticyclonic spell in the fourth week. There was a fair spread of wind directions during the month, but the second and third weeks were zonal W or SW’ly.
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April 2024 – Weather summary
My auto headline in my 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 gridded weather application for the weather in April 2024 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. was “Mild, wet and rather dull”, which I sums it up quite succinctly. I wrote the code for the auto-headline routine 10 years ago now and it still does a pretty good job. I tried to get an answer from Chat GPT about what it thought the weather had been like and all I got was this. 😜
April 2024 – Weather summary Read More »
April 2024 – CET
I make April 2024 the 12th joint warmest since 1659 in Central England, and the warmest since 2020. The early warmth at the beginning of the month was cancelled out by a rare cold spell at the end. Despite the 30 year linear trend showing warming of +0.15°C per decade, the 10 year running average has been on a slide.
April 2024 – MSLP
The resident Icelandic low for April was displaced southeastward again this month by higher than average pressure across Greenland, and lower than average pressure in the northern North Sea, leaving the British Isles in a slack cyclonic westerly flow on the mean pressure chart.
April 2024 – MSLP Read More »
April 2024 – Global temperature
In my DIYDIY Do It Yourself global temperature series April 2024 tied with April 2016 as warmest with a mean of 10.17°C and anomaly that was +0.18°C above the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO.. I wonder how much of an underestimate that was this month?
April 2024 – Global temperature Read More »
April 2024 – Mean temperature anomalies
Temperatures betwixt and between across the British Isles once again.
April 2024 – Mean temperature anomalies Read More »
Flannan Isle Storm – December 1900
Flannan Isles Lighthouse is a lighthouse near the highest point on Eilean Mòr, one of the Flannan Isles in the Outer Hebrides off the west coast of Scotland. It is best known for the mysterious disappearance of its keepers in December 1900. From what I read in the Wikipedia article the disappearance of the three lighthouse keepers occurred on the 15th of December or shortly thereafter.
The weather from the 15th to the 17th from what I can see in the reanalysis charts was quite rough to the west of the Hebrides, with a westerly gale on the 15th,that backed southwesterly by the 16th. The switch to a tropical maritime air mass would explain the poor weather conditions reported by the steamer “Achtor” later on the 15th. As for the men being swept off the island by a freak wave who knows, the gradients are tight so there must have been gale force winds at that time, but possibly not storm force.
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Latest NAO-CET-UKP
I’ve just refreshed the three graphs in an application I use to calculate a simple NAONAO The North Atlantic Oscillation (NAO) is a weather phenomenon over the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level (SLP) between the Icelandic Low and the Azores High. Through fluctuations in the strength of the Icelandic Low and the Azores High, it controls the strength and direction of westerly winds and location of storm tracks across the North Atlantic. index with from gridded reanalysis 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. data I download from NOAANOAA NOAA 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.. We still await a second major NAO event in 2024 that will hopefully break the prolonged spell of mobile and cyclonic weather we’ve been experiencing since the middle of January. Maybe this anticyclone over 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. forecast for this weekend will be the start of it. 🤨
Latest NAO-CET-UKP Read More »
Daily temperature extremes in central England
I’ve added another viewer, to the ever expanding list of viewers that I’ve developed over the years, to the application I use to visualise data from the daily Central England Temperature series. This one finds all the daily extreme warmest and coldest daily temperatures, highest maximum, lowest minimum, the highest minimum and the lowest maximum etc etc. As you can see in the screenshot above it consists of three data grids with a matrix of months and days to display the year the extreme occurred (left-hand grid), along with the actual value (centre grid), and the resulting anomaly (right-hand grid). In the above example I’ve highlighted in yellow any records that occurred in this decade (2020-2024) which is quite remarkable as they are still a full five years to go before it ends.
I’ve also added functionality to generate a simple animated GIF of the results in a single image.
Daily temperature extremes in central England Read More »
Warm start to spring 2024 in Central England
I’ve redesigned how I visualise moving averages in my Daily CETCET Central 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 LTALTA Long 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 😉
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Met Office App – Forecast Temperature Verification
I download the site specific NWPNWP Numerical weather prediction uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. data that resides in the HTML 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 application requests whenever anyone looks for a forecast for a location for a number of my applications I’ve written to visualise the forecast data in a table, graph or on a map. Parsing the data was a tricky business, but I persevered, and can now grab a week of one and the three hourly data for any number of elements including temperature.
As well as visualising the data, I thought it might be interesting to do a spot of forecast verification by comparing the three hourly forecast data with the actual values from 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. observation for any location in the world.
I know that the forecast values although quite accurate, are far from being spot on. The question I was intrigued to find out was just how accurate they are. Here are some recent preliminary results I have produced from the add-on to my 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 NWP application I wrote a number of years ago.
Notice the very warm day on the 6th of April associated with storm Kathleen, and how underestimated temperatures at Kinloss were because of a slight foehnFoehn A 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. effect.
Generally a pretty good result with temperatures +/- 2°C at Heathrow.
Again at Exeter temperatures within +/- 2°C of the forecast, although it didn’t do well with some of the minima, and the 8th of April was a bit of a disaster because heavy rain suppressed temperatures.
I’ve noticed that recently the Met Office are in the process of updating the NWP data their app uses, so they must have some concerns themselves about its accuracy, although the changes in the NWP might have more to do with forecast weather, rather than forecast temperatures. At the moment I am still using the old data and haven’t switched to the new trial data. In the meantime, let me know about what you think about the accuracy of the forecasts the Weather App produces in your area. I’ve still got a bit more testing, tweaking and bug fixes to do to my verification application, but I’ll keep you posted.😉
Met Office App – Forecast Temperature Verification Read More »
Spring 2024 – Abnormal warmth in central Europe
Is it possible to get a heatwave in Spring? I beleive it is, and it seems to have already happened at least once since the start of astronomical spring in central Europe. I reckon that maximum temperatures anomalies of 10°C above the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. constitute a heatwave day. The definition of a heatwave of course is that these high temperatures should occur for at least three consecutive days or more. So the charts I’ve constructed are just a simple count of days with anomalies higher than 10°C. I’ve not any deep research into this, but have just added a chart for 2023 for a comparison. I think, like a lot of others do, that with global surface temperatures and North Atlantic SSTSST Sea Surface Temperatures being at unprecedented high levels as they are at present this is portentous, and summer across mainland Europe could see a record number of severe heatwave events and the risks that this brings. Hopefully I’m proved wrong, and surges of warm air flooding up from the tropics won’t occur too frequently.
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Dates of earliest and latest frosts in Central England
Not surprisingly, in this ever warming world of ours, the dates of the earliest and latest air frosts in Central England getting respectively later and earlier. The code behind that produced the scatter graphs below was a lot harder than I imagined. Along with the scatter graph and data grid, I also decided to add a smaller horizontal bar chart just to plot the annual distribution. The application is a lot more versatile than just finding the earliest and latest frosts and will come in useful in spotting other events in the daily CETCET Central England Temperature series.
As you can see from the linear trend in the graph below of minimum temperatures, the date of the latest air frostair frost An air frost occurs when the temperature of the air falls below 0.0°C in Central England is now closer to the 5th of April, much earlier than the 16th it was back in 1878.
The date of the first air frost is now 11 days later on the 13th of November, rather than the 2nd of November, as it was closer to back in 1878.
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March 2024 – Objective LWT
March 2024 was a mobile affair, and often quite cyclonic, with only brief anticyclonic interludes between before the arrival of the next low. 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. during the month was well below the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., particularly in the last week.
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