Memories of late November 1973

Looking at the latest long-range forecast charts from the GFS for T+192 (fig 1) and T+336 (fig 2) reminds me of the last few days of November 1973, which saw an early cold spell from a similar outbreak of northerly winds (fig 3). I had just left the Met Office (for the first time), and had started working as a trainee bank clerk for the Trustees Savings Bank at a new branch they had just opened in Dronfield, northeast Derbyshire, and can still remember the snow.

Figure 1 – 8 day forecast – courtesy of www.netweather.tv

Figure 2 – 14 day forecast – courtesy of www.netweather.tv

Figure 3

It also extends the run of northerly outbreaks which started on the 29th of October with a period of approximately 7 days, that’s of course if the GFS forecasts come to pass, although the northerlies now seem to have taken a liking to Thursday rather than Sunday!

  • Sunday 29th October [N]
  • Sunday 5th November [N/NW]
  • Sunday 12th November [N]
  • Sunday 19th November [NW] although the main thrust is east of the meridian at T+84
  • Thursday 23rd November [CN] 7 day cycle slipped a bit!
  • Thursday 30th November [N]

Now the acid test – what do the Met Office think of this northerly theme? Well to be perfectly honest not a lot, if you look at their latest extended forecast out to the end of November (fig 4). This outlook is couched with so many vague and bland phrases I can’t see what practical use it has for most people.

Figure 4 – Courtesy of the Met Office

A critique of the October news release

I should skip this post now if you don’t like me having a go at what the Met Office push out in their various social media outlets, because I’m just going to give an honest critique of what I think of their latest news release that’s looking back at the weather of October 2017:

Textual content

I can’t really fault what they say about last month’s weather, I’ve written quite a few monthly weather diaries for the UK myself, and know that it’s not easy to condense everything into one and keep it readable, although I do wish they would fully justify it!

Colour contoured charts

I’ve always like the colour contoured climate charts that the Met Office produce. Although they haven’t changed for at least twenty years or more it still looks professional, but I think it’s about time to see what ArcGIS can do.

Climate tables

What let’s the whole article down in my opinion, is the inclusion of the badly formatted HTML tables of climate values (fig 1). This is what’s wrong with them in my opinion:

  • Both tables are left aligned on the page and not centred.
  • The values in the columns are left and not right aligned.
  • The titles in the header are left aligned and not centred.
  • Why not use the word ‘anomaly’ or simply ‘anom’ rather than ‘Diff from average’?
  • Why not combine the two tables into one like this (fig 2):

Figure 2

I’ve generated this graphic from a bespoke application that I use to downloads and visualise the free gridded monthly data that the Met Office make available. Obviously this is a graphic file, but I could have just as easily output HTML. I think you’ll agree that it’s much more professional and more importantly easy to read than the Met Office offering? (If not get an appointment with your optician as soon as you can). The good thing about doing this in software, is that it’ll work just as well for next month, as it would for January 1963. Here’s a screen shot with all the regional values for January 1963 as an example (fig 3).

Figure 3

The most anticyclonic November

Figure 1 – Data courtesy of the CRU/UEA

November is not renown for being an anticyclonic month in the British Isles. As you can see (fig 1), November is one of the few times in a year when cyclonicity is on a par with anticyclonicity. So looking at a ranked list of anticyclonic November’s since 1871 (fig 1), the number of any November’s that are over 50% anticyclonic (when using the Objective Lamb Weather Type as a crude measure) is quite small.

Figure 2 – Data courtesy of the CRU/UEA

As you can see, joint top of the list of most anticyclonic November’s along with 1942, is the year 1988, when 15 of the 30 days were pure anticyclonic.

Figure 3 – Data courtesy of the CRU/UEA

An anticyclonic Autumn month in November can only spell mean one thing as regards weather is concerned – frost and fog – and 1988 did not disappoint in that regard. The headline in the Monthly Weather Report for November 1988 read:

“Generally sunny and dry; cold at night with frequent fog”

Figure 4 – Data courtesy of Wetterzentrale

Looking at the daily charts it’s easy to see why it was so foggy, and it was also the 10th driest November in the UK since 1910, and fourth sunniest since 1929. In the Review of Autumn 1988 in the Weather Magazine, R.A.S. Ratcliffe said when explaining about the upper air pattern across the northern hemisphere for November 1988:

On the 500 hPa monthly mean chart the circumpolar vortex was split, with part over Novaya Zemlya, and part over northern Canada. The jet stream was unusually strong in the eastern Pacific, but the most unusual anomalies of 500 hPa height were -140 m over western USSR, and +100 m over the UK.

I don’t have that particular 500 hPa level chart to hand, but I can generate the mean surface pressure anomaly chart for the month (fig 5).

Figure 5 – Data courtesy of NCEP reanalysis

October 2017 – very mild by night so far

The first two weeks of October have been very mild across the country, but not particularly by day, because day time maximum have remained close to average, but by night, where some places have seen minimum temperatures [18-06]  as much as 3°C above the long-term average (fig 1).

Figure 1

There have only been a few ground frosts across the British Isles so far this month, and those were mainly in the northeast and central Ireland (fig 2), it looks like it could be yet another mild Autumn the way things are going.

Figure 2

Incidentally, if you do find that I leave Scotland out of a map in any of my articles, please let me know and I will add one, it’s just that monitors favour landscape rather than portrait orientation, and when I zoom in to get extra detail,  something has to go.  As far as I know, I have just the one subscriber from the north of the border at the moment.

BBC News: Bid to rescue Ben Nevis weather data

Figure 1 – Courtesy of the BBC

Believe it or not, the hourly weather observations from Ben Nevis from 1898-1902 have still not been digitised. It’s a real shame that the Met Office haven’t already done this on behalf of the nation, instead of relying on volunteers at Weather Rescue to do it for them (fig 2). But then again, they have their hands full, because they still have at least fifty years of climate records that the Victorians left them that also need digitising, because at the moment their climate records only extend back to 1910 for temperature and rainfall, and 1929 for sunshine. It’s not that the Met Office haven’t been round for all that length of time because they were established in 1854 as a small department within the Board of Trade by Vice-Admiral Robert FitzRoy, it’s just that when they did discover computers, they were too busy doing other things with them to bother adding the climate records that they held in the archives.

Figure 2 – Weather Rescue

Personally I think as much effort that’s gone into digitising these records, ought to be put into to reestablishing the Observatory on top of the Ben. Well not exactly Observatory such as the Victorians built, more an automatic weather station, similar to the one on top of Cairngorm. I realise that there’s already a SIESAWS on Aonach Mor just across the Coire Leis from Ben Nevis, but its lower (1130 M), and simply doesn’t have the prestige of being sited on top of the highest mountain in Britain gives it. Power to the AWS would obviously be the main problem, and an extension lead 4,411 feet in length would simply be out of the question. Solar panels may help a little, but they would ice up easily and disappear under rime for most of the winter. A large rack of lithium-ion batteries may do it, but who would pay for them to changed by helicopter every month. A small wind turbine might do it but that again would ice up, maybe eventually some kind of fuel cell might be the answer for these remote places.

This is what the directors of the Scottish Meteorological Society said about the closure of the Ben Nevis Observatory in 1904:

“It is to the Directors a matter of profound disappointment that in this wealthy country it should have been found impossible to obtain the comparatively small sum required to carry on a work of great scientific value and interest, and that they are now obliged to dispose of the Observatory buildings and dismiss the staff”

It seems that little has changed in the last hundred years or more since its closure.

So if you have an hour to spare, why not volunteer your time to help digitise the Ben Nevis observations? I’m sure it won’t be long before the Met Office, in these days of financial austerity, see the potential in this idea, and will open up their archived observational records to volunteers to be digitised too!

Met Office : Earlier budburst linked to warmer springs

I have a book in my library entitled “Weatherwise – England’s weather through the past thirty years‘ by John H Willis and published in 1944. John Willis who died in 1962, kept faithful records of temperature, sunshine and rainfall for many years and took photographs of trees on the same day each year. Strangely his work on phenology, which has been largely forgotten these days, came to a similar conclusion as this joint study between the Met Office and Woodland Trust did. I don’t think somehow that these results will come as any great surprise to people who love the weather and the countryside.

Figure 2

This is a graph and table (figs 2 & 3) from a study that I did myself using daily CET data earlier this year, to see just how much earlier the first day of spring was occurring in 2017 than it was in 1772. I reckon that the first day of spring now occurs three weeks earlier than it did in 1772 in Central England.

Figure 3

 

 

Autumn is on it’s way – the last 8,760 hourly temperatures at Exeter

Figure 1

Ever wondered what a scatter graph of hourly temperatures for a year looks like? The chart above (fig 1) does exactly that for Exeter airport, along with a 24 hour (black) and 7 day centred moving averages to boot. The cool morning temperature of 5.8°C from the airport, reminded me that Autumn is on its way, even though for the first few days of the coming week 1000-500 hPa partial thicknesses will be in excess of 564 dm. The 7 day moving average which peaked in June at close to 20°C, and has been declining erratically since the middle of July.

Figure 2

The sunshine stats may well be a little low for Exeter, with an annual total of just 1414.3 hours, this is because the sunshine record is not 100%. There are occasionally missing values from the SYNOP reports that I can do little about, December 2016 had quite a number, and might explain the odd behaviour of the moving average (fig 2). Even so, the sunny spells that did occur in early April, and in the second half of May are clearly visible, as is the warm and sunny June in both temperature and sunshine graphs.

State of the UK Climate 2016

The Met Office have just released the third edition of their State of the UK Climate for 2016. I always find that this a strange time to publish such a document, why not by the end of January? But once you have taken a look at the 59 page document, you’ll see that it must take a lot of work to put it all together, and I am just being my old curmudgeonly self.

There’s an interesting correction at the foot of the article about CET, which as most of you know is something I like to talk about at length. I find it amazing how people scour the climate datasets to pick out a new extreme, be it high or low, this one’s no exception – decades that span 10 years but don’t start on a year that ends in a zero aren’t what I would call a decade. It’s time to see what the Collins dictionary definition of a decade is:

A decade is a period of ten years, especially one that begins with a year ending in 0, for example 1980 to 1989.

So they are strictly correct, but personally I still like to think of a decade as a period that starts with a year that is divisible by 10 without a remainder, as the Collins dictionary definition suggests it is. Anyway back to the correction, what they were initially said was that the period 2007-2016 was the warmest ‘decade’ in the whole series back to 1659. Obviously they noticed that something was wrong, and said it was incorrect. I wonder why they didn’t just delete the reference in the HTML? I was certainly late on this one and never saw the original.

Just out of interest, here is a centred 10 year moving average of monthly CET values since 1900 (fig 2), and as far as I can see, the warmest decade was the one from 1997 to the end of 2006, when the mean 10 year anomaly for the first time just exceeded +1.0°C, since then, Central England has cooled, until about 2012, when annual anomalies increased sharply again. I think the reason they corrected the original article could have been for a typo, because 2007-2016 and 1997-2006 are just ten years apart. They can always ask me to provide them with graphs, I have a graph of CET values to suit just about any occasion, and the bonus is that I work cheap.

Figure 2

Here for completeness is the full 10 year series of moving averages since 1659 (fig 3).

Figure 3

And finally the infographic that the graphics team have produced to advertise the publication of the 2016 report is a bad idea to my mind. I love a well designed infographics – you only have to look at my blog to see that – and I do realise climate statistics are not the most exciting things to try to visualise, but a clear well constructed table or graph is really all you should need. Most of us have moved on from kindergarten I would have hoped, but they may have been instructed to produce a simple infographic for politicians the like of Michael Gove to understand what’s going on.

Figure 4 – Courtesy of the Met Office

High risk of unprecedented rainfall

Figure 1 – England Wales Precipitation (October – March) 1766 – 2016 – data courtesy of the Met Office

Dr Adam Scaife has been at it at the Met Office again, or more correctly I should say that Dr Vikki Thompson the lead author of the report ‘High risk of unprecedented rainfall in the UK in the current climate‘ has. News of her findings are in the latest Met Office blog, in which she says:-

“Our computer simulations provided one hundred times more data than is available from observed records. Our analysis showed that these events could happen at any time and it’s likely we will see record monthly rainfall in one of our UK regions in the next few years”

According to the article:-

“Analysing these simulated events showed there is a 7% risk of record monthly rainfall in south-east England in any given winter. When other regions of England and Wales are also considered this increases to a 34% chance”

I can’t totally agree with her when she says in the included video that:-

“…older records are now no longer so relevant to the current risk because climate has changed over the past century”

My question to her would be – “why do we know climate has changed?” – the answer to that is because we already have existing rainfall data back to 1910, wouldn’t it then be wise to digitise all the rainfall data that the Victorian’s collected from 1859, and just see how unprecedented (and believable) the rainfall events that their new supercomputer has generated?

Sometimes I think that the NWP programmers have taken over the asylum Met Office, rather than the climatologists taking the lead in these investigations, or perhaps they’ve fused together as one being that does both.

They maybe onto a winner with this one though, because a quick look at the “real” (or as close as we are going to get it) gridded England Wales Precipitation from 1766, and the simple linear trend is definitely upwards and wetter by 22.7% in those 250 years (fig 1). If the total rainfall across the October-March period has increased, then you would logically infer that the number of unprecedented months has also increased.

The article goes onto say:-

The authors have named this novel research method the UNSEEN method to emphasize that this analysis anticipates possible events that have just not yet been seen.

I can’t see a link to the report that they are talking about in the blog, so it maybe that they’ve applied the “unseen method” to that, and we are to rely on the infographic (fig 2) for people with really short attention spans like myself.

Figure 3 – Courtesy of the Met Office

So if Climate change is likely to increase the frequency and magnitude of severe flooding events as many people think, why has rainfall declined, and not increased in the other half of the year? I reckon that April to September precipitation is 13% lower than it was 250 years ago (fig 3). But of course older rainfall records are now no longer as relevant these days, because the climate has changed so much, and we should probably just disregard it.

Figure 4 – England Wales Precipitation (April – September) 1766 – 2016 – data courtesy of the Met Office

What’s the sunniest month of the year?

I thought that I would investigate and find out exactly what climatologically is the sunniest month of the year using monthly sunshine data from the Met Office. The gridded sunshine record only started in 1929, but I’ve been reliably informed by someone in the know at the Met Office, that plans are well advanced to extend this (along with the rainfall and temperature series), back to at least the start of the 20th century, which I applaud, although in my opinion it’s a long way overdue. The add-on to my application looks not only at sunshine, but rainfall and temperature too, and for any region within the United Kingdom. The pie chart I’ve include is for England & Wales (fig 1), and reveals, surprisingly to many I bet, that May is climatologically the sunniest month of the year in 35.2% of years since 1929, followed by June in 31.8% of years, and July in 19.3% of years.

Figure 1 – Data courtesy of the Met office

Also rather surprisingly, it can happen that in some years April is the sunniest month. According to my application that’s occurred five times, in 1945, 1954, 2002, 2007 and 2011, so three times in the last 15 years. There’s always a chance that I’ve made an error let me know if I have.

The sunniest month in the entire England and Wales record was the July of 2006 with 287.6 hours of sunshine (fig 2). The sunniest month in the famous summer of 1976 was also a July with 251.5 hours of sunshine, but ranked only 13th in the list of sunniest months in a year.

Figure 2 – Data courtesy of the Met Office