Mad about the weather

Definition of a Gale

Gales around the coast of the British Isles are a fairly common occurrence, but inland they occur much less frequently. In the media the word ‘gale’ seems to be bandied about with little thought of what it actually means. According to the fourth edition of the Meteorological glossary, published in 1963, a gale was a 10 minute sustained mean wind speed of 34 knots (39 mph) or more. As an observer from 1970 to 1995 that’s what I always thought the definition was, but in the sixth edition of the glossary, published some thirty years later, I notice that the definition has been updated to include gusts of 43-51 knots (49-58 mph) as well. So a gale can occur without a mean of 34 knots or more if a gust reaches Beaufort force nine or higher, which to me confuses the whole issue. The definition of a gale day remains the same.

I notice the definition in the Marine Forecast glossary on 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 website rather ambiguously fails to mention at all sustained mean speed of 10 minutes in its definition of various gale warnings.

Global Temperatures | December 1993 – December 2023

All but the usual 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 and JMAJMA The Japan Meteorological Agency (気象庁, Kishō-chō), abbreviated JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. Met Services have now published their December 2023 estimates. Despite the missing series, I thought I would generate my 12 month moving mean anomalies for the last 30 years for the leading seven data series anyway. It’s plain to see that in 2023 thay have all shot up, almost exponentially😮. The previous warmest 12 months set in 2016 is now just a distant memory. The 30 year linear trend for the 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. series is showing a rise of 0.216°C per decade, the ERAERA 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 even higher than that at 0.236°C! All very alarming.

The discriminatory impact based warning system

The above is an amber warning issued for Brighton and Hove, East Sussex, Kent and West Sussex for Monday the 22nd of January 2024. It’s a perfect example of how winds in Scotland have to gust in excess of 80 mph before an amber warning is issued there, but only 70 mph in England. Below is 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’s own UKV model for 06 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 Monday morning, the spot values clearly show gusts of 69 kts across NENE North East Scotland and 61 kts across the coast of Sussex.

The impacts on a roof or chimney stack are identical, the last time I checked, the laws of physics are exactly the same in Brighton as they are in Kirkwall, and a 70 mph gust that removes slates off a roof in either place will have the same consequences if it falls on someone’s head. But impact based warnings are weighted in favour of population density, and hence the reason why the 69 kt gust is viewed as less ‘impactful’ in the NE Scotland than the 61 kt gust in Brighton. Completely balmy. Impact based warnings are discriminatory, and not for the right reasons. Bring back threshold based warnings.

13-19 January 2024 | Cold Spell

I might fill this article out with some extra detail when I get the time. At the moment I am watching the slow thaw of 10 inches of snow in StrathpefferStrathpeffer Strathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469. which I find very distracting and rather depressing 😪

Frost severity definition

The definition for frost severity as laid down by the Meteorological Office in their Glossary of 1991, has remained unchanged for many years. Frost severity is dependent not just on the lowest minimum temperature, but also on the wind speed, so there are two sets of values for ‘slight’, ‘moderate’, ‘severe’ and ‘very severe’, one for when mean wind speeds are 10 knots or more and one for when they are less.
There are many euphemisms for frost used by today’s weathercasters that are simply misleading and bad practice. Common amongst these are ‘sharp’, ‘touch’, ‘pinch’, ‘hard’, and ‘light’, they’re all bollocks as far as I am concerned. If weathercasters stuck to the same rigid definition the general public might have a better clue to just how severe an upcoming frost might be, what a forlorn hope of mine that will ever happen.
It’s also interesting to note that the glossary mentions just two basic types of frost, an ‘air frostair frost An air frost occurs when the temperature of the air falls below 0.0°C’, and a ‘ground frost’, so forget about ‘grass frost’, even if the thermometer that’s used to measure it is referred to as a ‘grass minimum’ thermometer.

It’s no wonder northerlies don’t have the bite they once had

The waters around 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. are all still well above average for early January. In fact the southern North Sea is +1.7°C above the LTALTA Long 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 SSTSST Sea Surface Temperatures than they usually are.

Latest Sea Surface Temperatures

The latest SSTSST Sea Surface Temperatures were a bit of a surprise. I realise that globally SST are currently at record levels, so I was surprised to see how much blue there was on the chart. Obviously the belt of high anomalies in the central Pacific, Atlantic and Indian ocean must be at very high levels indeed. The northern Baltic has managed to ice up this year, but SST in the Black Sea and Mediterranean are still well above average.

The continuing saga of the missing Tórshavn observation

^{_{14 Jan 2024 1400 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).
Replete with the observation for 06010}}

Anyone who loves 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 as much as I do, and likes a plotted chart of NW Europe, will bemoan the missing SYNOP observation from Tórshavn. It’s been missing for a good number of years now, and leaves a big hole in a plotted surface chart between Scotland and Iceland. It’s akin to 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 decision to run just one radiosonde station in Scotland, the demise of Stornoway and at Shanwell leave a similar gap in the upper air coverage across the north 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. too.
My running joke on the missing 06011 SYNOP is that the 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. should shellout on buying a Vantage Pro AWSAWS Automatic Weather Station and just gift it to DMIDMI The Danish Meteorological Institute is the national meteorological service for Denmark and Greenland. so the Faroese could install it in the capital Tórshavn. It’s not that the Faroese are shy of technology, a good number of it’s 18 islands are now connected by undersea tunnels, which also boast the world’s first undersea roundabout, so they do know a thing or two about engineering, but seem to have very little interest in monitoring the weather.
Anyway what I’ve done today is simple enough, I just wrote a new procedure to download the latest METARMETAR METAR is a format for reporting weather information. A METAR weather report is predominantly used by aircraft pilots, and by meteorologists, who use aggregated METAR information to assist in weather forecasting. Raw METAR is the most common format in the world for the transmission of observational weather data. from Vágar, the islands only airport. The ICAO is EKVG, and it’s associated WMO number is 06010. Instead of fetching the METAR from OGIMET, I download it from the ADDs server run by 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. in America. I can now at a click of button fill the big gap with pseudo SYNOP complete with QNH parsed from the METAR. It’s pure idleness on my part why I didn’t add this functionality many years ago to my old SYNOP application.

The Bermuda Triangle of Scotland

Although we’ve seen a number of snow showers this morning in StrathpefferStrathpeffer Strathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469., they all proved light and were on their last legs before they managed to put a dusting down along the Strath. This is our sixth winter here, and I reckon that snow showers in a winter situation like this with a 30-40 knot N’NW gradient generally have a range of around 90 km as they come in land from the north coast before they simply just run out of steam, or should that be water vapor. Obviously with a stronger gradient, deeper cold air and increased instability, or change in wind direction that 90 km longevity might well increase.

Spectacular inversion

Snow covered Munros sticking out of the inversion

Inversions are quite common in anticyclonic conditions, and there’s been one in the last week 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. where an intense anticyclone (1046 hPahPa A Hectopascal is the SI unit of pressure and identical to the Millibar) has been meandering across northern Scotland for much of that time. Yesterday (11 January 2024) the inversion lowered to ~3,000 feet across Scotland to allow the Munro’s to peek above it. This morning the dew pointDew point The dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. on Aonach Mor (1130 M and just to the south of Ben Nevis) dropped to -34°C and the humidity to ~5% which is extremely low and doesn’t happen that often.

Further east in the Cairngorms a similar thing happened on CairngormCairn Gorm Cairn Gorm (Scottish Gaelic: An Càrn Gorm) is a mountain in the Scottish Highlands. It is part of the Cairngorms range and wider Grampian Mountains. With a summit elevation of 1,245 m (4,085 ft) above sea level, Cairn Gorm is classed as a Munro and is the seventh-highest mountain in the British Isles. itself. The thermographs below are for Cairngorm itself (1245 M) and the AWSAWS Automatic Weather Station on the edge of Aviemore (220 M) in the Strathspey. Despite the low stratus at Aviemore temperatures still fell close to -4°C, whilst on the tops it was a relatively balmy 4°C.

Above and below the inversion, from the Ptarmigan Restaurant and Loch Morlich.

Many years ago as an observer at RAF Kinloss I remember contacting Rob McElwee at the 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. (I can’t for the life of me remember how I did this, I must have phoned) to alert him to the fact that we had spent that day walking on Cairngorm and the northern corries in warm sunshine above the inversion. He managed to show a visible satellite image of the UK in his evening forecast (9.25 pm?) that showed the only bit of high ground peeking above a sea of low cloud covering the UK was the northern Cairngorms, good old Rob McElwee!

Weather Presenters 1954-2024

I’ve added some more faces to my rogues gallery database of 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. TV weather presenters. I’ve now got 190 of them, and I would say that there are still some more of them out there to add to it. Interestingly over 55% of those are female. There’s a bit of fuss about it this year, since it’s now 70 years since George Cowling presented the first in-vision forecast on TV in 1954, whatever that means, beating the first newsreader to it by several months. A wee bit too young to have appreciated George’s approach, but I’ve seen a fair few of them have a go, for good or bad since then.

After recent severe cold spell milder air invades Scandinavia

Scandinavia has seen a spectacular turn of events in that milder air has advected eastward and temperatures in some places are over 30°C higher than they were just 48 hours earlier. The ease with which this transition occurred has been truly remarkable in nature, with little or no precipitation on the change from severe cold to milder weather.

^{_{7-9 January 2024 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). –}} ^{_{48 hour temperature differences}}

Here’s a thermograph from an aerodrome at Jokkmokk in northern Sweden to see the remarkable rise in temperature from a low of -38°C on the 5th, to a high of 5°C earlier today.

RAF Waddington

This reply 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 regarding air temperatures from airfields being contaminated by aircraft activity makes me smile when I think back to some of the stations I worked as an observer. Even from more than 100M away or more an English Electric Lightning could generate some heat, and noise, as it was warming up on the taxiway! To compound this possible contamination the Met Office today use very sensitive thermometers in their AWSAWS Automatic Weather Station, and not the mercury thermometers that were around when I was an observer. There are a lot of well sited AWS stations 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., but most of the AWS at airfields such as Heathrow are pretty poor. Take a look at these aerial images of the siting of the enclosure at RAF Waddington in Lincolnshire for instance, a key 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 key climate stations.

As you can see although the Stevenson screen enclosure does sit on a triangle of grass it’s surrounded by two car parks and the perry track, where aircraft taxis to and fro to the main runway at takeoff or on landing.

If you’re interested to find out more about UKMO observing sites check out this link.

3 January 2024 – Temperature anomalies

The cold air across Scandinavia still won’t relinquish its hold in early January, and we are left with a topsy-turvy anomaly chart, with a belt of warm anomalous air extending from the Atlantic, northeastward across Iceland and into the Arctic Ocean. Either side of this belt of very mild air, across northern Europe and Greenland, anomalies are as low as -17°C in Finland, and -22°C in western Russia. The paradox is that globally, temperatures are still at record high levels never seen before, well at least since 1850 when records started.

The most anticyclonic January – 1992

It looks like this January (2024) could turn into a very anticyclonic month from this weekend, so I thought I would take a look back 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. records, which started in 1871, and found that January 1992 was the most anticyclonic on record., although despite it being so anticyclonic, it never really managed to generate more than a few easterly days at the start of the third week.

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. that 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. got close to 1050 hPahPa A Hectopascal is the SI unit of pressure and identical to the Millibar on the 26th as you can see from the chart for 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)., the highest on that chart was 1049.0 hPa at Cynwyd in Denbighshire. I only have main synoptic hour data so it may have broken through 1050 hPa. Notice that they’re also plotted 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. reports from Cape Wrath, Butt of Lewis and Binbrook on that chart, those were the days 😉

One other point about January 1992 is that it was also a El NinoEl 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 month.

Mean Sea Level Pressure – 2023

At a glance it looks like 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. 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. in 2023 was more often below average than it was above. There were a couple of notable anticyclonic spells in January and February, and again from mid May into Mid June, but that was about it, with extended cyclonic spells in January, March, July and from mid October to mid November.

UK Precipitation – 2023

Using the UKPUKP UKP is a gridded datasets of UK regional precipitation. daily rainfall 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 it looks like Northern Scotland has still the lowest POAPOA Percentage Of Average of all Regions 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. at 103.7%. The line series in the graph for the other regions in the UK are more amplified and wetter, with the Central region of England having the highest 133.4% POA. This time last year Central region were ~87%. It looks like 2023 started close to average and just steadily got wetter.

The latest Oceanic Niño Index figures

The latest El NinoEl 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 is going great guns in the central pacific, no doubt helped along by a surge in SSTSST Sea Surface Temperatures in the Pacific as well as in all the other oceans of the world. Because of the complicated rules, this is the first time I’ve seen El Nino conditions confirmed, and which started with the three month mean of SST from May, June and July of 2023.

Circulation – December 2023

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. anomalies in December were not too dissimilar to those of November, with the Icelandic low pushed further south into mid-Atlantic by higher than usual pressure across Greenland. Pressure was lower than average across the 55N latitude from Scotland east into the southern Baltic(-8 hPahPa A Hectopascal is the SI unit of pressure and identical to the Millibar) and higher than average (+5 hPa) to the west of Portugal. This all added up to a tight W’SW flow from the central Atlantic across England and Wales, and eastward on into Germany and Poland. All a result of a south shifted jet stream for much of the month.

Leave a Comment / January 3, 2024

Circulation, MSLP

Circulation – December 2023 Read More »

Global Temperatures | 2023 | New warmest year

In my DIYDIY Do It Yourself Global Temperature series I can now reveal the worst kept secret of 2023 has finally proven to be correct in that 2023 has finally overtaken 2016 to become the warmest calendar year on record. I make the mean temperature in 2023 to be 10.21°C, which is 0.36°C above the 1991-2020 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO.. That makes it fractionally warmer than the 10.16°C of 2016, the previous warmest year. The last seven months of 2023 all set new records so the fact that it would be the warmest year was a bit of an inevitability. The latest 30 year annual linear trend shows a warming of 0.15°C/decade.

Leave a Comment / January 3, 2024

Global Temperatures, Global Warming

Global Temperatures | 2023 | New warmest year Read More »

Global Temperatures | December 2023 | 7th Consecutive Warmest

December 2023 became the seventh consecutive month to set a new highest monthly record. Again it did it by another large margin in my DIYDIY Do It Yourself Global temperature series. The December mean 0f 0.53°C was 0.16°C higher than the previous warmest December in 2015. The question I wonder about is what happens to the meteoric rise when it comes full circle this June?
Currently the latest daily global mean I’ve calculated for the 31st of December is still out on it’s own in record breaking territory.

Leave a Comment / January 3, 2024

December, Global Temperatures, Global Warming

Global Temperatures | December 2023 | 7th Consecutive Warmest Read More »

Global Temperatures – December 2023

With large parts of the world anomalously warm, the cold belt stretching from Greenland, across Scandinavia and on eastward into Siberia and China persisted. 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. this cold belt to the north enhanced the N-S thermal gradient, thanks in no small part to a warm tongue of positive anomalies extending NW from the Balkans, no doubt the result of the many warm sectors that affected southern areas of the UK during the month. Temperature anomalies of 9°C above the LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO. across North America were nothing short of extraordinary.

Leave a Comment / January 3, 2024

Anomalies, December, Global Temperatures

Global Temperatures – December 2023 Read More »

Circulation – December 2023

December 2023 ended up being a mobile month with the jet stream for much of it south shifted, which made it more cyclonic than normal, and hence a rather windy month too with four named storms. The 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. zonal index was negative for the first week or more, but went positive in a big way from the second week onward. Quite a few classic analyses 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 during the month ranging from a plethora (thanks CK) of troughs on the 1st & 2nd to multiple occlusions on the 31st (thanks Mr Occlusion).

Leave a Comment / January 3, 2024

Circulation, December, LWT

Circulation – December 2023 Read More »

UK 12 month moving averages | 1993-2023

A thirty year linear trend reveals that 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. 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 LTALTA Long Term Average. This is usually defined as a 30 year period by the WMO..

Leave a Comment / January 3, 2024

Precipitation, Sunshine, Temperature

UK 12 month moving averages | 1993-2023 Read More »