The north of Scotland was the driest, sunniest, coldest and frostiest region in the UKUKThe United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. in December 2023. It’s a shame the UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy don’t provide a chart showing mean wind speeds which this month would show that it’s also been pretty windy too. The +0.1°C mean temperature for northern Scotland has been
I wrote this warnings viewer to display the latest warnings issued by the NSWWSNSWWSThe National Severe Weather Warning Service is a service provided by the Met Office in the United Kingdom. The purpose of this service is to warn the public and emergency responders of severe or hazardous weather which has the potential to cause danger to life or widespread disruption. This allows emergency responders to put plans into place to help protect the public and also allowing the public to make necessary preparations. at the Met OfficeUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy several years ago. But since then, time and HTML wait for no man, and I’ve spent some time performing radical surgery on it to get it working again. The UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy are planning to publish an API for it soon to make this process much easier, but my request for a key has been denied it’s not for personal use, apparently it’s only for ‘business to business’ users whoever they are. The parsing of the HTML Is rather tricky, but I think I’ve just about got it more-or-less cracked, except for occasions when there are multiple maps for a warning. Why do it? Because like Everest it’s there! I can now archive warnings and revisit them. Having access to the shapefile for the warning areas means I can zoom in on the map if needs be, and there’s no reason why in the future I couldn’t overlay snow depths, wind gusts, rainfall & temperature values on it for verification purposes.
The mean temperature in 2023 just quite couldn’t overtake 2022 as the warmest year on record. Still the mean anomaly since pre-industrial times, which I calculate using a 1772-1850 LTALTALong Term Average. This is usually defined as a 30 year period by the WMO. baseline, is just a smidgeon under +2°C and warming at a rate of 0.18°C/decade.
I’ve developed yet another Windows weather application, one that I have been meaning to write for several years now, it analyses reported hourly wind speed and gusts in SYNOPSYNOPSYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting weather observations made by manned and automated weather stations. SYNOP reports are typically mad hourly and consist of groups of numbers (and slashes where data is not available) describing general weather information, such as the temperature, barometric pressure and visibility at a weather station. observations from WMOWMOThe World Meteorological Organisation is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics. block #03, and produces a simple daily and hourly gale index [GIGIGale Index] for all available stations below 250M, which usually ends up being around 150 sites across the UKUKThe United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. and Ireland. I’ve done it to see how viable it would be for an organisation, such as the UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy, to come up with an objective, rather than a subjective way of naming storms. The screenshot above shows a data grid of hourly GI in the main form, with daily and hourly data from the 26th of September up to the 21st of December 2023. I have now analysed all hourly SYNOP data back to 2015, which is the year naming storms commenced in the UK.
The GI itself is very simple, and is just the sum of the mean Beaufort force for each station plus half the Beaufort force of it’s highest gust, from all stations for that hour. I’ve found that from looking at all previous named storms that an index of 100 equates to a gale and 200 to a named storm event. You can see the seven named storms we’ve seen since the start of the 2023/24 season. Using these values as a guide I can easily list all the named storms. Some of these were named other Met Services other than the UKMO, and a couple of the storms were named for their heavy rain rather that strong winds.
This is where the fun starts, because as you can see Pia, a storm named by the DMIDMIThe Danish Meteorological Institute is the national meteorological service for Denmark and Greenland. on the 21st of December, had a maximum hourly GI of 709 which is at least twice as high as any of the previous named storm so far this season. It was eventually named, but surprisingly not by the UKMO. If you look down the table you’ll also notice storm Ciaran only had a GI of 169, and using the 200 threshold for storms as a guide it should not have been named. There are plenty more named storms like Ciaran that just didn’t make the grade. There are also other times when a GI exceeded 200 but that didn’t result in a storm being named. On looking back I’ve found that this often occurs when a low affects Scotland, and I beleive it’s because the UKMO link the naming of storms with their NSWWSNSWWSThe National Severe Weather Warning Service is a service provided by the Met Office in the United Kingdom. The purpose of this service is to warn the public and emergency responders of severe or hazardous weather which has the potential to cause danger to life or widespread disruption. This allows emergency responders to put plans into place to help protect the public and also allowing the public to make necessary preparations.. Usually, but not always, if they issue an amber warning a storm automatically gets named, sometimes a yellow warning is all that’s required outside Scotland, but because the threshold for an amber strong wind warning is 80 mph (or higher) rather than 70 mph for elsewhere in the UK, amber warnings are rarer in Scotland. That’s the reason why I believe the UKMO didn’t choose to name Pia. The next logical step is to break down the GI regionally because that’s it weakness. Below is a ranked list of all the named storms since 2015 and all the missed events. As you can see I have also assigned each named storn a category from one to five. Ciara, a category five storm, had the highest maximum GI of any of them. In third place you’ll notice is the Ross-shire (or the unnamed) storm of January 2015 which I’ve included because it occurred just before the naming of storm commenced.
This application is still WIPWIPWork In Progress so ignore the mean column for now I will get round to fixing it.
Call me old fashioned or even out-of-date if you like, but Tristan Gooley book ‘The secret world of weather’ does contain a number of errors in my opinion. I’ve not read it cover to cover because I don’t particularly like his writing style (‘joyful breeze’ I don’t think so 🤨), and compared with a really good book about the weather, such as Gordon Manley classic ‘Climate and the British Scene’, this book comes a very poor second. Take for instance Tristan’s description of ‘glazed ice’. He seems to be confused with ‘ground ice’ and ‘glaze’ or clear ice. Glaze is formed when supercooled water droplets come into contact with objects such as trees or roads the temperature of which are close to freezing, and when they do, a layer of ice forms instantly on the object. Frozen water on roads and paths is dangerous enough, but the results of glazed ice are far more dangerous. I’ll add to this post if I find any other goofs when, and if, I attempt to read any more of it. 😉
Two bits of bad news about CO2CO2Carbon dioxide (chemical formula CO2) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. levels as measured at Mauna Loa. First up, they still continue to inexorably rise as they’ve done every since they were first monitored back in 1958. Second up, after the rate of change slowed from 3 ppmppmParts Per Million per annum to ~2 ppm in Autumn 2022, it’s now started to increase again, and the 12 month average stands at 2.41 ppm as of November 2023. I wonder if they’ll ever come a day in what’s left of my lifetime when they’ll start to fall, I very much doubt it 😥
Global monthly temperature anomalies have exceeded 1.5°C above pre-industrial levels nine times or so in individual months in the HadCRUTv5 series since 2016. I’ve adjusted the baseline of the chart above by the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO. for the 1850-1900 period to calculate the increase in temperature since the start of the pre-industrial age. Some global series don’t extend as far back as 1850, GISTempGISTemp v4The GISS Surface Temperature Analysis version 4 is an estimate of global surface temperature change using data from NOAA GHCN v4 (land stations) and ERSST v5 (ocean areas). 4 for example, so I imagine they can’t use this value and the LTA must be reduced to 20 years. I’ve added a 3 year linear trend (warming at the rate of +1.094°C/decade) to the chart above, and extrapolated it forward to find when 12 month average global anomalies will reach +1.5°C if temperatures remain at their record levels for the next nine months or so. The 12 month moving average could achieves this by November 2024, until six months ago I wouldn’t have believed this were possible, but with six consecutive record warmth months, I now beleive it’s perfectly possible. If you take a more measured approach, and use a linear trend over the last 30 years (warming at the rate of +0.213°C/decade), then the 1.5°C won’t be reached for another 10 years, that’s in January 2034. So when will it be? My money’s on 2024, but I could be wrong. 😉
Most regions in the last year have been between 10% and 25% wetter than average, all regions that is apart from northern Scotland which has been slightly drier. The whole series is tipped on its head with the northeast, central and southeast regions much wetter than average. All thanks are probably due to a south shifted jetstream for long spells since the end of June.
The AWSAWSAutomatic Weather Station at Altnaharra is situated not in a glen like most weathercasters would have you believe, but in a broad strath close to the river Mudale a short way from it’s exit from Loch Naver as it heads west to the sea. True it is surrounded by mountains, with Ben Hope to the N’NW and Ben Klibreck to the SE, but it’s definitely not in a ‘sheltered glen’. The station itself sits on an open site next to the A836 at 81 M amslAMSLThe height Above Mean Sea Level. just to the north of the hamlet of Altnaharra, to call it a village would be to a disservice to any village.
Meteorological Autumn 2023 has seen some quite varied weather types, predominantly anticyclonic until mid October and then full on cyclonic. It also contained four named storms, some of which were more deserving than others for being named. I can’t even remember them all, only Ciaran and Debi stick out. Zonality also did a couple of about faces during October and again towards the end of November.
In November it looks like the semi-permanent Icelandic low decided to do some early Christmas shopping and head southeast towards Scotland. Thanks to blocking, from Greenland across to northern Scandinavia, for much of the month, anomalies were low from Denmark to eastern Russia (-12 hPahPaA Hectopascal is the SI unit of pressure and identical to the Millibar) and higher (+8 hPa) to the northeast of Iceland. Much of the cyclonic activity in the first half of the month took place at latitude 50° north, the North Atlantic’s answer to the roaring forties. 😉
Here’s a closer look at the daily charts and associated LWTLWTLamb Weather Types are often used in UK-based analyses, with individual weather patterns based on the eight primary cardinal directions (N, NE, E, SE, S, SW, W, NW) plus cyclonic (C), anticyclonic (A) and unclassified (U) types. and GIGIGale Index.
The curious thing is in a record warm world why has it been so cold in the last month in our bit of it? Answers on a postcard to the editor if you please.
The scores-are-in, and it’s a ten-from-Len, as the world produces a sixth consecutive record warmest month for November, which is a record in it’s own right. I make the daily mean for November 9.81°C which is 0.22°C higher than the previous warmest in 2015. It’s not quite as impressive as in previous months, but nonetheless it’s still quite remarkable. The Daily values from my DIYDIYDo It Yourself series are no less impressive as you can see in the graph below. This year started setting daily records at the beginning of June and it’s been #1 daily warmest for much of the six months since then. Remember you heard it first here even if it was a racing cert 😉
The number of hours below 0°C in the last 96 hours Please note the CairngormCairn GormCairn 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. and Aonach Mor SIESAWS went offline as soon as the cold spell started😁
After unprecedented warm spells at both the start of September and October, Autumn 2023 was always going to end up being one of the warmest on record, and for along time it was, but the single cold spell at the end of November prevented this happening, and it ended up the third warmest since 1659, behind 2006 and 2011 with a mean temperature of 12.2°C, which was 1.4°C above 1991-2020 LTALTALong Term Average. This is usually defined as a 30 year period by the WMO..
Mean temperatures were close to average across England and Wales and southeast Scotland but slightly below average across the north and west of Scotland. Rainfall was above average in the south but much of Scotland was drier than average. Sunshine was well above average across England, the southwest and northwest of Scotland and Northern Ireland but much duller across west Wales, southwest England and northeast Scotland.
October 2023 Estimated Global Temperature Anomaly ERA5ERAERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera). The fifth consecutive warmest month by another massive margin. I knew it was going to be warmest but the margin with which it did it surprised me again. Almost 0.4°C warmer than 2019.Estimated global temperature anomalies ERA5 Since the start of the latest El NinoEl NiñoEl 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 event in June global temperatures have been turbo charged.October 2023 Estimated Global Temperature Anomalies 12 Month moving averages. They’re all skyrocketing! The 30 yr linear trend on ERAERAERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera). 5 is now +0.24°C/decade and exceeds the previous highest in 2016.
Did you know that a minimum air temperature of 0.0°C is NOT a frost? An air frostair frostAn air frost occurs when the temperature of the air falls below 0.0°C only occurs when the air temperature in a Stevenson screen falls below zero celsius i.e. goes negative and not before. The Met OfficeUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy website in an item about the types of frost is wrong. I did inform them of the fact and they have promised to correct it.
The UKMOUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy are in pretty good company not understanding what the exact definition of frost is, neither do the “experts” down at the Royal Meteorological Society either. I informed them about this slip up on their website a while ago, but so far the haven’t bothered to reply.
I notice that the Royal Meteorological Society have now corrected the ‘Touch of frost’ article on their website about the definition of what an air frost is, but not so much as a thank you from them. At least I did get a reply from the Met Office help desk, but it still hasn’t been corrected on their website the last time I looked.
I was astounded to find when I bought the book by the Met Office called ‘Very British Weather’ to add to my collection of books on weather and climate, that they had it wrong too.
On page 181 of the book I notice it states that ‘freezing conditions’ occur ‘when the temperature is at or below 0°C’. There’s no arguing that 0.0°C is the freezing point of water, but ‘freezing conditions’, even an ‘air frost’, surely can’t occur until the air temperature is below that temperature, and not at it. It’s a small even a trivial point, but these three instances are or were all wrong. I’m still trying to understand what the paragraph at the foot of the page is trying to say.😉
What a month. The Icelandic low decided to move 700 miles further south for a change of scene. It started well enough, but became cyclonic from the 19th onward.3 Aug-1 Nov 2023 50N 5W Pseudo Barograph Anomalies of -40 hPahPaA Hectopascal is the SI unit of pressure and identical to the Millibar in the last week close to the Lizard.
A perfect example this month of how gridded climate data, even when interpolated onto a 1 km x 1 km fine grid, can make some places drier and warmer that they really where.
Wettest Octobers 1836-2023 Rather Surprisingly, only E Scotland had a record wet month in the gridded regional data.Oct 2023 Rainfall POAPOAPercentage Of Average I’m not convinced with the contouring. I’ve never looked at it in detail before It’s neither caught the 228% in StrathpefferStrathpefferStrathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469. (dark blue) or the 219% at Tain, and seems to have completely missed the 408% at WattishamThe interpolation & smoothing used by the Met OfficeUKMOThe Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy in producing its 1 x 1 km gridded data seems to have remove the wettest spots such as Wattisham completelyOctober 2023 Mean temperature anomalies Strange, several stations with anomalies of -0.5°C or lower across the Scotland not registering as a blue contour fill including Baltasound“though areas further north were generally closer to average”. Not quite accurate statement for some places across NENENorth East Scotland, and that includes Baltasound in Shetland, mean anomalies were 1°C below the LTALTALong Term Average. This is usually defined as a 30 year period by the WMO.
The 12th mildest October since 1878. Mean temperature 12.1°C and +1.3°C above the 1991-2020 LTALTALong Term Average. This is usually defined as a 30 year period by the WMO..
I make October the warmest on record globally making it five record months in a row, remember you read it here first😁 Not as devastatingly warm as it was in previous months, but nonetheless warmer by a fair old margin.
There’s always a steep fall off in global temps at this time of the year. 2023 is still managing to hang in there as warmest, but it’s got stiff opposition in the next few weeks from 2016.
Another very warm month across the Arctic. Warm in S Europe & NENENorth East America, but rather cold across Central N America and Scandinavia. North-south temperature gradient very evident across the UKUKThe United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland..
Not so much an item as a Twitter dump of stories, charts, graphs and images from tweets I wrote concerning Storm Babet. Not sorted out too well chronologically either. I’ll try to do better next time. Maybe I’ll stick with the blog and just upload links to Twitter from now on?
20 Oct 2023 12 UTCUTCCoordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). Temperatures & Anomalies Rather cold in the NENENorth East, much milder further south. Not a single mention of temperatures for today on the BBCBBCThe 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. too caught up on listing the number of flood warnings21 Oct 2023 08 UTC Surface analysis Something like that20 Oct 2023 13 UTC Surface analysis19 Oct 2023 11 UTC Surface analysis18-20 Oct 2023 Anemograph Inverbervie is a notoriously windy place, but the E’ly gale that’s been running there for the last 31 hours must rank as one of the windiest spells the AWSAWSAutomatic Weather Station there has ever recorded18-20 Oct 2023 48 hr totals Estimated rainfall totals from weather radar I’ve used the lower colours to make things a bit clearer over the wider UKUKThe United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland..20 Oct 2023 14 UTC A surprisingly dry and bright day with sunny intervals here in StrathpefferStrathpefferStrathpeffer (Scottish Gaelic: Srath Pheofhair) is a village and spa town in Easter Ross, Highland, Scotland, with a population of 1,469. after yesterday’s afternoon rain, although it feels cold in the strong easterly wind.21 Oct 2023 Flooding on the A834 Strathpeffer to Dingwall road close to Castle Leod21 Oct 2023 00-16 UTC Estimated accumulations from weather radar The heavy rain has finally stopped after almost 13 hours. Quite remarkable accuracy with estimate of 43.1 mm for Strathpeffer, Vantage Pro reports 43.4 mm Goodbye BabetOctober 2023 Strathpeffer Three large rainfall events 6-8 Oct the storm that never was 87.6 mm 48hr 19 Oct storm Babet 32.6 mm in 16 hr 21 Oct 29.2 mm in 9 hr so far 192.4 mmStrathpeffer totals 00-00 rather than the 09-09 totals from Dingwall, nevertheless still much wetter 5 miles further westThe average for October here is 102mm, so we are already close to 200% with still another 9 days to go15-22 Oct 2023 Inverbervie Anemograph19-22 Oct 2023 Mean Speed Average hourly [kts] A 33 kt mean speed is not bad going for 72 hours at Inverbervie.18-20 Oct 2023 CairngormCairn GormCairn 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. Last 48 hrs The wind has moderated slightly this morning but still blowing force 12 from SE’E. Temperatures now sub-zero and wind chill close to -12°C so it’s either white or has a very icy glaze up there at the moment21 Oct 2023 14 UTC Glenshee Snow above 2500 ft today now clearing from southeast.19 Oct 2023 20 UTC Amazing rain shadow cast by Cairngorms persists across Nairn & Forres. Kinloss 0.4 mm [06-18] Lossiemouth 0.8 mm [06-18]19-20 Oct 2023 02 UTC Estimates from radar Had to change to high colour range contouring Purple pixels indicating wettest areas have seen >175mm in last 20 hrs across E Scotland, and close to the city of Aberdeen itself. 32.4mm in 14 hrs in Strathpeffer19 Oct 2023 06-20 UTC Rainfall totals from weather radar estimates More white pixels appearing across E Grampians indicating totals of >80mm since 06 UTC. Ben Wyvis has some too as well. 17.4 mm since 13 UTC here in Strathpeffer in heavy rain.19 Oct 2023 1510 UTC Here’s a pseudo hyetograph for a spot close to the Bridge of Dee gleaned from 5 minute weather radar imagery. Estimates of 41.6 mm so far today.
