December 2024 was a very wet and a rather mild month in StrathpefferStrathpeffer Strathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469. with almost 9 inches of rain.
Strathpeffer – December 2024 Read More »
5th – 11th January 2025
Altnaharra
3 hour forecast temperature verification
Data 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 Weather App
I doubt if you’ll ever see a temperature forecast as way out as this one got. It was issued by 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 in their weather app on the 5th of January for Altnaharra in Sutherland. The blue line in the top chart shows three hourly forecast temperatures for the next seven days. The red filled area shows air temperatures taken from AWSAWS Automatic Weather Station observations for Altnaharra. The lower bar chart, shows the difference between the forecast and the observed. Although the forecast for the 7th to the 9th was reasonably accurate, the 10th and 11th got progressively worse, with forecast temperatures being as much as 20°C too high at one point. I’m not sure what NWPNWP Numerical weather prediction uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. model the Met Office use for these site specific forecasts, but it has got some severe problems, and not just with record cold temperatures I might add.
Altnaharra forecast temperature verification Read More »
The latest estimated Arctic sea ice extent is the third lowest for the 10th of January at 13.103 million square kilometres, thats 91.7% of the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. and ~880,000 lower than it was this time last year. Someone has definitely left the fridge door open here.🥵
Arctic sea ice extent third lowest on record Read More »
Antarctic sea ice extent has steadily improved in the last month and now stands at 99.6% of the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO.. Sea ice extent is up by ~900,000 square kilometres from this time last year, and close to 2 million square kilometres higher than the lowest for this date back in 2023. Obviously someone remembered to keep the fridge door shut down there this summer🥶
Antarctic sea ice extent at 99.6% of average Read More »
Here are some of the plotted charts from eleven of the lowest temperatures that have occurred 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. since 1961. I’ll add to the charts when I get more time, but as I only have 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. data back to 1973 I can’t include the ones from the early 1960’s. So to start the show, here are the joint coldest temperatures of -27.2°C from 1982 & 1995.
The lowest temperatures since 1961 in the UK Read More »
I first came across the term ‘prebaratic’ or ‘prebar’ when I joined 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 in 1970 as an assistant. To me the term was synonymous with the ‘T+24 forecast chart’ which we received at outstations by MOLFAXMOLFAX An early type of fax machine using wet paper.* from Bracknell every six hours. I never realised until now that ‘prebaratic’ was a rather crude acronym for “barometric pressure distribution over the Atlantic” until I read this in the 1956 book ‘Weather Map’. It’s hard to believe that these prebaratic charts were the very forecast charts which we take for granted these days.
* This is a MOLFAX recorder which was an essential piece of equipment at outstations. This is an image of a MUFAX machine made by MUirehead. I’m sure we didn’t call it MUFAX back then, but MOLFAX, don’t ask me what that acronym stood for, but you can be sure Met Office was in there somewhere. The Met Office have always been good at inventing acronyms. 😉
Prebaratic Charts Read More »
We’re getting onto halfway through winter now, and I wondered just how well 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 were doing with their forecast for this winter they issued on the 25 November 2024.
Well, mean temperatures are +0.7°C above average, that’s despite the ongoing cold spell, but not as mild as the 45% on the mild side of average suggests, so 6/10.
Total rainfall also looks higher than average, and higher than forecast with all these flood alerts around at the moment. December was rather dry, particularly in the S, but a forecast of 30% on the wet side of average still looks a little too low, so maybe only 8/10 for that.
The UKMO provide no LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. for wind speed that I can find to calculate anomalies with, and surprisingly they don’t forecast sunshine, which is pretty important for the nations vitamin D3 levels. 😎
How are we doing with the forecast for winter 2024-25 [DJF]? Read More »
Here are charts I generate from a program I have that calculates gridded temperature extremes for any region based on their WMOWMO The World Meteorological Organisation is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics. location. At the moment that’s just Wales, Ireland, Scotland, England and 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.. It’s pretty crude, because it depends on a mix of available stations be it coastal or inland, but if they don’t change, and they don’t, and I ignore mountain stations, and there are no more than four of those, the results look pretty good, at least for comparison purposes.
Here are the results for the three months up to the 6th of January 2025. As you can see, there have already been at least two significant cold spells this Autumn and Winter, both were colder and longer in Scotland than they were in England, and that’s usually how things are, in a northerly.
But despite the ‘floodgates to an Arctic blarst’ being opened in the far north, it maybe a day, sometime even longer before the cold weather reaches the south, and 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 and 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 finally take notice.
This has happened multiple times each winter since we’ve returned to Scotland, and bugs me every single time. There, I’ve got it off my chest now, my therapist will be delighted 😉
Scotland – England | Daily gridded temperatures | 6 Oct 2024 – 6 Jan 2025 Read More »
I bought a Tapo webcam this summer produced by TP-Link, and since then it’s sat on our bedroom window sill looking NENE North East’ward and down the strath. No subscription involved, it faultlessly connects to your wi-fi and stores hi-res video it takes onto a micro-SD card for a couple of weeks, before reaching the end and starting all over again, loop recording. It’s viewable from anywhere in the house from my smartphone, I suppose you might be able to view it remotely over the internet, but I’ve never tried it, as I don’t get out much these days. There are a couple of things I am disappointed with, at night, because it automatically goes into infrared mode at a certain light level, it doesn’t capture constellations or planets. The other thing it doesn’t do a very well I’ve found are colourful sunrises, which are often disappointing, with colours that are not as extensive or as vivid as they are in reality.
The one thing I can’t show are time lapse videos of fast moving skyscapes or strong convective clouds development, for the simple reason I didn’t save any 😖.
December 2024 was a rather anticyclonic affair, and zonal in nature. There were some cyclonic interruptions though, notably on the 6th and 7th with Storm Darragh, but after that pressure rose quickly with an intense high forming close to northern Scotland from the 9th to the 13th. A couple of other deep depressions tracked eastward close to the north of Scotland on the 18th and 22nd, producing gales and storm force gusts, but 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 deemed neither were worthy of being a named storm. I produced this data from six hourly reanalysis data rather than just the daily data from the CRU at the UEA, I wonder if anyone will even notice?
December 2024 – Circulation Read More »
December 2024 was a month dominated by very much higher than average pressure in the central North Atlantic (+14 hPahPa A Hectopascal is the SI unit of pressure and identical to the Millibar). The resulting strong and broad, west southwesterly flow, stretched right from Canada in the west, across the North Atlantic and Baltic, and on into Siberia in the east. There’s little wonder that December turned out to be one of the mildest on record in 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..
December 2024 – MSLP anomalies Read More »
A bridge between two large positive temperature anomalies, one in the west of in Hudson Bay (+11°C), the other in the east in the Kara Sea (+7°C), spanned the North Atlantic in December. Either side was generally cooler, Southern Greenland was anomalously cold (-5°C), as was much of the southern North Atlantic, Mediterranean and near East. Anomalies across 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. in the bridge were a toasty +1.6°C above the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO..
December 2024 – Temperature Anomalies Read More »
I make the mean global temperature anomaly in 2024 a full 1.6°C above the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. in pre-industrial times. This is warmest year in the series which started in 1940, and is around 0.12°C warmer than it was in 2023. If it warms at the same rate as it’s done over the last 30 years, linear trends suggest that a 30 year average of +1.5°C will occur in just over five years time, in July 2030.
Globally 2024 warmest on record +1.6°C above the pre-industrial era Read More »
I make December 2024, using 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). daily global temperature data, the second warmest globally in the series that starts in 1940. Mean anomalies were just under 1.7°C degrees above the pre-industrial LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., and close to 0.1°C lower than they were in December 2023.
Global Temperatures – December 2024 Read More »
The climate 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. during 2024 was :-
2024 – Weather Summary Read More »
December was a very mild month 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., the fifth warmest in the UK to be exact since 1884, with a mean temperature of 6.2°C, that was +2.0°C above the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO.. Rainfall totals were closer to average though, at 110% of the POAPOA Percentage Of Average, the wetter weather in the north balancing out the drier weather across the south. It was a very dull month across the board, sunshine totals were the fourth lowest since 1910, at just 57% of the POA.
Weather Summary – December 2024 Read More »
2024 was the fourth warmest year since 1659 in central England, with a mean temperature of 10.95°C, which was 1.69°C above the 1659-2024 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO.. In the last 50 years, mean temperature in the series have been rising by 0.29°C per decade. A linear trend for the full series shows a rise of 0.03°C per decade over that time. We’ve not seen a lower than average annual temperature since 2010.
2024 fourth warmest year since 1659 in central England Read More »
Precipitation Totals Estimates from weather radar
Due to the New Year’s revelry we were enjoying until 6am this morning, this story of torrential rain & flooding across N England totally escaped me. Overnight 30 to 50 mm of rain fell quite widely, with more that 80 mm on the Pennines in the 15 hour period until 09 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). on New Years day, resulting in local flooding across the region.
Wed, 1 Jan 2025 – Torrential Rain Read More »
1 Jan 2025 1230 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).
A well defined, and remarkably straight, squall line across the southeast of England.
Who says nature abhors a straight line?
Well it was William Kent as a matter of fact.
Who says nature abhors a straight line? Read More »
December 2024 ended up with a mean of 6.8°C, that’s 1.9°C above the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO., making it the joint 12th mildest since 1659.
Some places in England remained frost free.
December 2024 – CET Read More »
There are two varieties of CETCET Central England Temperature data which you can download 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, they are the monthly series from 1659, the daily series from 1772 for daily mean temperatures, or the daily maximum and minimum series from 1878. So if you want monthly means in central England, you are either stuck with using ‘meteorological’ seasons by adding up three monthly means to get a seasonal mean, or alternatively adding up 90 or so daily values, and calculating either a meteorological or an astronomical seasonal mean. And that’s what I’ve done with this bespoke viewer which allows you to view any season, be it astronomical, or meteorological, for any year since 1772. It’s a big improvement on using monthly data, because as well as looking at meteorological seasons, I can now view astronomical seasonal means, as well as the latest three months of daily data, or see how the latest season is doing. By the way, you are now deep in weather nerdland with this article. 😜
Autumn 2024 – Central England Temperatures Read More »
Rather than look at climate data for a single station for month, season or year, I thought it might be useful if you could look at climate data for all available stations for a specific region. It’s easy enough to filter stations for a particular region using their WMOWMO The World Meteorological Organisation is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics. number, that’s supposing there are enough stations in that region to calculate a meaningful value for. So for 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., I can now look at temperatures and anomalies for England, Wales, Scotland, and Ireland, or for the whole of them combined, for any given period. It’s crude, but more effective that you might think. The above charts are for the three months prior to Christmas Day 2024 for the whole of the UK and Ireland, in this case that’s data from an average 136 stations each day, which excludes all stations of 300M amslAMSL The height Above Mean Sea Level. and above. I’ll get back to you on accuracy of this simple method, when I’ve run some verification tests against regional 1.5 km gridded data 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.
UK Regional Temperature Data Read More »
Yes, lee waves and gravity waves are related phenomena, but they are distinct in their context and characteristics:
| Aspect | Gravity Waves | Lee Waves |
|---|---|---|
| Definition | General waves caused by gravity as a restoring force. | A specific type of gravity wave caused by airflow over terrain. |
| Cause | Broad (e.g., buoyancy, storms, etc.). | Flow of air over topography. |
| Location | Atmosphere, oceans, or other fluids. | Downwind side of mountains or ridges. |
| Motion | Can be traveling or standing waves. | Typically standing waves. |
Lee waves are a subset of gravity waves, specific to atmospheric conditions involving terrain-induced airflow.
Is there any difference between lee waves and gravity waves? Read More »
The choice between impact-based weather warnings and threshold-based weather warnings depends on the context and the needs of the users. Both have advantages and limitations, but modern meteorological services are increasingly favoring impact-based warnings due to their ability to communicate risk more effectively. Here’s a comparison:
Warnings are issued when weather conditions reach or exceed predefined thresholds, such as a specific wind speed, rainfall amount, or temperature.
Warnings are issued based on the anticipated impacts of weather events, considering factors such as vulnerability, infrastructure, and local preparedness.
| Aspect | Threshold-Based Warnings | Impact-Based Warnings |
|---|---|---|
| Focus | Weather conditions (e.g., wind speed, rainfall). | Potential impacts on people and property. |
| User Relevance | Less tailored to specific needs. | Highly relevant and actionable. |
| Flexibility | Fixed and rigid thresholds. | Adaptable to local context. |
| Complexity | Simple and easy to issue. | Requires more analysis and resources. |
Impact-based weather warnings are generally better, as they focus on what matters most: the effect on people, property, and the environment. These warnings enable better preparedness and response by tailoring information to the situation’s real-world consequences.
However:
The trend among meteorological services globally, including 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. 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, the National Weather Service (US), and others, is to shift toward impact-based warnings to improve public safety and response.
Which are best impact or threshold based weather warnings? Read More »
