The stormy winter of 1989/90

synops-1200-utc-on-thu-25-jan-1990

The Burn’s day storm (1200 UTC 25 January 1990)

Since I’m in a bit of a stormy mood at the moment, and have recently been working on some software to measure the storminess across the British Isles in a new kind of way, I thought that I would take a look back at the stormy winter of 1989/90 (remember the Burn’s day storm of the 25th of January, well actually the Burn’s night storm?) and see how it compared with last winter (2015/16), which according to the Met Office (if you believe them that is) was one of the stormiest on record with as many as eleven named storms!

Well the first ranked table of winter gale days answers the question immediately and quite definitely. The winter of 1989-90 was head and shoulders the stormiest in the objective Lamb Weather Type [LWT] series that started in 1871, with a total of 58 gale days and a mean gale index [GI] of 32.4. Last winter did manage a very creditable joint eighth place ranking with 38 gale day, but was no match for 1989/90 or the stormy winters of 1989-90 (#2) and 2013-14 (#3). I think the Met Office would have had their work cut out for them big time if the naming of storms had been in existence back then.

2016-10-29_095544

Winter Gale Index  1871 – 2015/16

Here is a complete set of charts showing the number of gale days, the mean gale index and the anomaly from the Winters of 1871/72 to 2015/16, the winters  in this case are of the astronomical kind 21st December to 20 March.

2016-10-29_095520

Annual number of gale days (1871-2016)

2016-10-29_095527

Annual mean gale index (1871-2016)

2016-10-29_095534

Annual anomaly of gale days (1871-2016)

Those charts were from the old application that used the daily LWT from the Climate research unit at the University of East Anglia, the next few charts are from my more recent application and give a more detailed look at the gale index for any particular period  and  use 6 hourly charts. The first is for 1989-90 and a you can see that January and February were a particular stormy affair. There were ten distinct storm periods during 1989-90 the stormiest winter on record.

 

2016-10-29_100916

Six hourly gale index  (1 October 1989 – 31st March 1990)

I have looked at the Met Office “named” storms from 2015-16 in a previous articles and found some of them fall short of what I would describe a true storm, a gale maybe but not a storm. The chart below can only identify five storms that occurred during the 2015-16 season, and not the eleven “named” ones.

2016-10-29_100847

Six hourly gale index  (1 October 2015 – 31st March 2016)

Finally for a bit of fun (really), I thought I would try to visualise all the gales and storms since 1948 in one chart. Can’t be done? Have a look at this monster piece of climatological DNA. It’s still a bit rough round the edges as a chart goes, but it does manage to show every gale index greater than 30. The reason I can’t go back before 1948 at the moment is that the reanalysis data changes from using a 2.5 x 2.5° grid to a slightly finer 2° x 2° grid before 1948. Why the National Centers for Environmental Prediction [NCEP] wouldn’t produce a finer grid in more recent years rather than the other way round beats me.

2016-10-29_102452

Gale days 1948-2016 (1 October – 31st March)

It’s Top of the Hots!

maximum-temperature-c-1800-utc-on-tue-13-sep-2016

Earlier this week I had a look at the recent hot September day on the 13th, and particularly at Gravesend-Broadness (WMO #03784) were the record of 34.4°C was set. I said in that article that to me Gravesend was one of the most unlikely hotspots that there could be situated as it is in the Swanscombe marshes, jutting out into the Thames on Broadness, that mud has a lot to answer for. It appears so regularly in the warmest places in the country it won’t be long before it has its own Facebook group and throngs of Japanese tourists trudging round it to pay homage. Anyway I thought I would do a little more investigating and find out just which station was at the number one spot in the Top of the Hots hit parade so far in 2016.

capture2

Courtesy of Bing Maps and the Ordnance Survey

And at number one, the warmest place in the British Isles is Gravesend with a massive 29 days! In second place the title holder for many years but now usurped by Gravesend, that old-time favourite London Heathrow with 22 days. The south-east of England has the greatest proportion of warm days as you would probably guess with St James Park in joint 4th place with 12 days, Northolt in 7th place with 10 days and Manston in 10th place with 7 days.  I make that approximately 80 out of the 261 warmest days occurred in the southeast this year.

warmest-place-by-day-in-the-british-isles-1-january-2016-18-september-2016

Here’s a look at the maximum temperature of each day this year from block #03 of the SYNOP observations. The bars are marked to indicate when Gravesend was the warmest place and the maximum temperature for that day. There is a proviso with these stats, and that is I have only allowed one maximum for each day, so if there was a joint highest the station with the highest WMO number will get it, I will revisit the code and fix that when time permits.

warmest-day-in-the-british-isles-highest-max-06-18-1-january-2016-18-september-2016

Lowest pressure in August

I got a little fed up with hearing every BBC weather presenter churn out the phrase “this are of low pressure is very unusual for the time of year” and decided to investigate the truth of the matter. Of course, it all depends on what you term “unusual”, I know personally that as I get older how easy it is to forget past events, and that the low now tracking into Ireland might not be that unusual at all, and that’s when gridded MSLP data and weather statistics drawn from that data come into their own.

I’ve used the NCEP reanalysis six hourly MSLP data back to 1948 to find the extreme mean sea level pressure [MSLP] range for August. I decided to look at a grid size that extended from 10W to 2.5E and from 50N to 60N a total of 30 grid points in total. I could go back farther but the grid size changes to a 2°x 2° grid from the 2.5° x 2.5° later grid and I need to write the code! There is one problem in the analysis in that it’s looking for a minimum pressure in the grid around the British Isles which won’t necessarily find a discrete low pressure circulation, but until I write an algorithm to do that with this will have to do.

Extreme MSLP August - British Isles [50N-60N 10W-2.5E] 1948 - 2016

Extreme MSLP August – British Isles [50N-60N 10W-2.5E] 1948 – 2016

As you can see the lowest MSLP in August in the vicinity of the British Isles was 972.3 hPa on the 24th August 2005, the one that’s affecting us at the moment is off the west coast of Ireland with a central MSLP of around 980 hPa and filling. Admittedly the lowest pressure then was just to the northwest of Scotland.

Extremw MSLP in August across the British Isles [1948-2016]

Extreme MSLP in August across the British Isles [1948-2016]

Here are just few of examples from the list of extreme low pressure systems across the British Isles that you may remember from the past.

Synops for Tue, 26 Aug 1986 at 0600 UTC

Synops for Tue, 26 Aug 1986 at 0600 UTC

Hard to say but the centre of this low over northern Scotland looks around 970 hPa on 30 August 1992.

Synops for Sun, 30 Aug 1992 at 1800 UTC

Synops for Sun, 30 Aug 1992 at 1800 UTC

This is the infamous low ‘Y’ that wreaked havoc in the Fastnet race in 1979.

Synops for Tue, 14 Aug 1979 at 1200 UTC

Synops for Tue, 14 Aug 1979 at 1200 UTC

Summer 1954 – worst in living memory?

In a recent article about the Summer Index  in Central England, summer 1954 came in at the bottom of the table with the worst possible scores for temperature, rainfall and sunshine since at least 1929. In researching for this article by looking back in the online archives of the Royal Meteorological Society, I did find that 1931, 1922 (mental note to find out why the summer of 1922 was so cold) and 1912 all rivalled 1954 as the worst summer on record, but I have a special affection for 1954 because it was in the summer of that year I was born.  Here are the headlines for the months of the extended summer of 1954 that I’ve grabbed from the Monthly Weather Report for each month that the Met Office make available online (they are Crown copyright – so I hope they don’t mind).

  • May 1954 Mainly dull and wet, with frequent thunderstorms; large variations of temperature.
  • June 1954 Mainly dull and cool; periods of rain, heavy at times.
  • July 1954 Notably cool and dull; wet in some areas.
  • August 1954 Cool and dull, mainly wet in England, Wales and southern Scotland.
  • September 1954 Cool and unsettled; wet in most areas; sunny on the whole.

To begin with I thought that I would just look back at the circulation patterns of the summer using the reanalysis MSLP data from NOAA, so the next three charts are the mean pressure for each meteorological month of the summer, followed by three more anomaly charts for June, July and August.  As you can see from the first three charts the summer was dominated by a west or northwesterly flow, which during July was quite strong.

Mean Sea Level Pressure 1 Jun - 30 Jun 1954

Mean Sea Level Pressure 1 Jun – 30 Jun 1954

Mean Sea Level Pressure 1 Jul - 31 Jul 1954

Mean Sea Level Pressure 1 Jul – 31 Jul 1954

Mean Sea Level Pressure 1 Aug - 31 Aug 1954

Mean Sea Level Pressure 1 Aug – 31 Aug 1954

The monthly anomaly charts for each month all show an anomalous low to the northeast or east of the British Isles, with mean pressure between -5 and -9 hPa lower than the monthly long-term average.

Mean Sea Level Pressure Anomalies 1 Jun - 30 Jun 1954

Mean Sea Level Pressure Anomalies 1 Jun – 30 Jun 1954

Mean Sea Level Pressure Anomalies 1 Jul - 31 Jul 1954

Mean Sea Level Pressure Anomalies 1 Jul – 31 Jul 1954

Mean Sea Level Pressure Anomalies 1 Aug - 31 Aug 1954

Mean Sea Level Pressure Anomalies 1 Aug – 31 Aug 1954

And here are the 1200 UTC surface temperature anomalies also from reanalysis data which show how cool, if not cold it was, not just across the British Isles but also the near continent through each of the summer months.

Air Temperature Anomalies 01 Jun to 30 Jun 1954

Air Temperature Anomalies 01 Jun to 30 Jun 1954

Air Temperature Anomalies 01 Jul to 31 Jul 1954

Air Temperature Anomalies 01 Jul to 31 Jul 1954

Air Temperature Anomalies 01 Aug to 31 Aug 1954

Air Temperature Anomalies 01 Aug to 31 Aug 1954

Here for good measure are the mean temperature anomalies for the entire summer courtesy of the Met Office.

1954_14_MeanTemp_Anomaly_1961-1990

Summer 1954 – mean temperature anomalies

The British Isles were in quite deep (for the time of year) cold air for long periods during the summer of 1954. I count 49 of the 92 days of that summer when sub 552 dm partial thicknesses (the green blobs) covered all or some part of the British Isles.

North Atlantic MSLP & 500 gh [WZ] Summer [JJA] 1954

North Atlantic MSLP & 500 gh [WZ] Summer [JJA] 1954 (courtesy of Wetterzentrale)

Of all the information and graphics that I have packed into this article, none of them conveys as much as the next graphic just how exceptional the Summer of 1954 was. It’s a chart of daily Central England Temperatures [CET] and anomalies for the entire Summer. The fifth chart from the top displays cold or warm spells that have lasted for four days or longer and were +/- 2°C  above the long-term average for that day, and as you can see in the entire summer there were only three warm spells, and all of them spells of high night-time minima rather than day time maxima.

Daily CET Summer [JJA] 1954

Daily CET Summer [JJA] 1954

Here is a list of the coldest summers in the CET monthly series since 1659. Although 1954 was cold, coming in at the 17th coldest with a mean anomaly of -1.19°C, there have been colder summers including that of 1922 with an anomaly of -1.72°C.

Coldest Summers (1659-2016)

Coldest Summers (1659-2016)

And finally a look at the daily rainfall totals for England and Wales from the UKP data series that are maintained and made available by the wonderful Met Office yet again. It was a wet summer and according to the figures it was over 40% wetter than average. It looked very wet from the 5th of June for at least ten days or so, with wet spells again in late July and again through the first three weeks of August.

HadUKP England & Wales 1 June 1954 - 31 August 1954

HadUKP England & Wales 1 June 1954 – 31 August 1954

In writing this article I’ve finally come to realise that I have developed an amazing set of applications to display climate data, but charts, tables and maps aren’t the be all and end all of what makes an interesting article about past weather events. To glue all those disparate images together you need meaningful textual information about whatever event your article is about, and if that event happened over sixty years ago like this one did, when you were either perhaps too young or not even born, then you can’t always write about it with the benefit of first hand experience.

British Isles Rainfall: 13 April – 13 July 2016

I still think that here in mid-Devon it’s been a rather dry spring and summer so far in 2016, although we did get a very wet day here in Bradninch on the 15th of June. Here are the 3 month totals from the SYNOP observations. Ignore the first mention of Exeter at the #1 spot being the driest place, the Met Office renamed the station on June 27th so that’s why it’s bone dry, the old Exeter total is at #7, so adding the two totals (124 mm) does mean that it has been dry during the last three months. The Rx column in the tables gives the percentage of SYNOP observations that I received to calculate the totals, so treat the Dishforth total with caution because I think the AWS may have been removed!

Wettest Places 13 April - 13 July

Wettest Places 13 April – 13 July

Of course Capel Curig is where it usually is at #1, that will probably remain the case until the Met Office publish more of the rainfall data from their climate stations in the Western Highlands of Scotland.

Wettest Places 13 April 2016 - 13 July 2016 WMO Block 03

Wettest Places 13 April 2016 – 13 July 2016 WMO Block 03

Accumulated Precipitation 13 April - 13 July

Accumulated Precipitation 13 April – 13 July

Treat the Orkney total with caution because I think there was a gauge problem with the AWS during this period.

Wettest Places 13 April - 13 July

Wettest Places 13 April – 13 July

Recent sunshine totals

Daily sunshine 24 May - 6 June 2016

Daily sunshine 24 May – 6 June 2016

Excuse the rant

I saw one of the BBC forecasters today show some sunshine statistics for the UK and the stark difference between the totals from the east and the west. That got me to thinking that I’ve never really done very much with sunshine stats from SYNOP observations, so I set myself a little task to knock up an application to do just that this afternoon. <rant>The reason why I haven’t done it before is probably due to the lack of sunshine reporting stations in the UK which are released by the Met Office! It might have its headquarters in Devon, but there is just one sunshine reporting station in the whole of Cornwall and Devon, have a look at the coverage in France and Germany and see the difference. There are many climatological stations out there that the Met Office are just never going to release the data for – this side of hell freezing over – which I think is a very great shame, in fact it’s worse than that, it’s a scandal, after all it’s our – the public of this country’s – data. My plea to the Met Office is to please release as much climatological data as you can, you might not want to do much with it, but I certainly can. The sad thing is that I wouldn’t even be able to process this data and present you with these maps, charts and tables if it wasn’t for a Spanish web site, if I depended on the Met Office I would have no observational SYNOP data, they would rather just sit on it </rant>.

The sunshine data

Anyway getting down from my soapbox and back to the sunshine totals from the last two weeks, below is a tabulated ranked list of the 52 sites across the UK, and as you can see Tiree tops the list with over 170 hours in 14 days, or 12.2 hours per day and 72.6 of the theoretical maximum available – if my astronomical functions are working correctly. Bottom of the list is poor old Leconfield on Humberside with just 21.3 hours in the two weeks, or just over 20% of the possible maximum. Having said that there are a great many cloudy stations at the bottom of the list, and all in the east of the country, all in all a very interesting spell of weather. Most of the southern and central European countries support the reporting of daily sunshine data in their SYNOP/BufR observations. The trick is because of the various time zones across Europe there are some countries that report sunshine at midnight rather than 06 UTC, so I still have some work to do for the more eastern countries to get the maximum coverage.

Daily Bright Sunshine 24 May 2016 - 6 June 2016

Daily Bright Sunshine 24 May 2016 – 6 June 2016