So Foul a Day and the Jet Stream

This country has never experienced anything like this before

Jon Snow Channel 4 News 12 Feb 2014 commenting on flooding in England

Like many other climate sceptics, my immediate reaction to this was to think that this was a load of utter rubbish. And I went looking for evidence to refute this poppycock. My first port of call was Alastair Dawson’s book So Foul and Fair a Day that chronicles the history of Scotland’s weather from the year 1600 based on  actual records. But first a look at some interesting evidence compiled by Paul Holmwood on his blog notalotofpeopleknowthat. Paul is in overdrive compiling data on historic flooding in England.

Paul has compiled the data for wettest months for the whole of the UK (Figure 1). January 2014 was wet and squeezes in at 16th place. Jon Snow lease take note! The data are displayed in Figure 2. Paul has this to say:

Interestingly, if you plot these months, they appear to be in clusters. Now, maybe that’s something Slingo should be looking at. (But I would not hold my breath).

Dame Julia Slingo is the Met Office’s chief scientist.

Figure 1 The wettest months in the UK since records began. The UK has experienced wetter conditions than January 2014 on 15 prior occasions since 1766.

Figure 2 The data from Figure 1 in graph form shows an interesting clustering of wet months. 

So Foul and Fair a Day

And so on to my friend Alastair Dawson’s book which I can warmly recommend to those with an interest in 300 years of climate catastrophe in Scotland followed by the quiescent 20th Century that most alive today assume is normal. Since UK records begin around 1766 I decided to pluck some quotes from chapter 6 of the book that covers the period 1750-1799. This was a period of upheaval in Scotland following the failed Jacobite rebellion of 1745 and the climate situation is made complicated by large volcanic eruptions on Iceland, Mt Hekla in 1765 and Laki in 1783. I have tried to avoid these truly anomalous periods.

Flooding on The Clyde

The Scots Magazine of 14 March 1782 describes how bad weather led to serious flooding in Galsgow. We read that;

On Tuesday last the River Clyde rose to a greater height than the oldest people in this city remember. It has sometimes overflowed that part of the town which lies very low; but upon this occasion, it rose about 20 feet of perpendicular height above the usual course of the river. This remarkable inundation was occasioned by a very heavy fall of rain and snow, which began on Sunday last, about 3 in the afternoon, and continued without intermission, all that night and next day. Upon Monday night, about ten o’clock, some parts of the Bridgegate were underwater, and the flood continued to increase. It was the greatest height upon Tuesday morning about seven o’clock.

At that time Bridgegate, the lower parts of saltmarket, Stokwell, Maxwell Srtreet, Jamaica Street and the populous village of Gorbals, were all underwater. The inundation was sudden and unexpected. Hundreds of families were obliged to leave their beds and their homes.

And on page 148

Across the Highlands and Islands powerful social changes were afoot. The year 1792, known as the Blianthne nan ba (the Year of the Sheep), was a key year in Scottish history, when many people were driven from their land to make way for sheep. The storms continued. December 1792 was one of the worst months, remarkable for the production of many deep depressions moving across the North Atlantic at unusually fast speeds and indicative of a very strong jetstream. A huge storm blew up on 9 December. Ferocious winds blew over the Shetland-Faoroe region, estimated at around Beaufort force 11 and 12.

The Goniel Blast

In 1794 a severe blizzard known as the ‘Goniel Blast’ took place in January. The blizzard was widely recorded in the Southern Uplands and led to the loss of life of many thousand sheep and the death of several shepherds in Dumfriesshire. For several days the snow fell so heavily that in some areas the snow was 50 ft deep. A total of 4000 sheep perished and the parish of Eskdalemuir. An effect of the frost was that many of the sheep that died in Scottish glens at this time were fit to eat, the word ‘goniel’ referring to flesh fit to eat although not killed by a butcher.

Dawson provides an account of relentless bad weather, much worse than today’s, punctuated by fine summers. The hardship brought about by crop failure and famine eventually led to millions leaving these shores for the New World. I have added emphasis to the passage on the jet stream since this seems to suggest that conditions similar to those of today also occurred back in 1792. One thing I believe that sceptics and warmists can agree on is that the current conveyer belt of Atlantic cyclones is linked to a fast moving jetstream that is farther south than we have become accustomed to. The question is what has brought about this “anomalous” behaviour.

The Jet Stream

Professor Dawson sent me a link to Netweather earlier this week, commenting that the polar stratosphere was very cold. Netweather have some neat forecast animations on their site. Figure 3 illustrates the problem we have with a powerful jet stream, orginating off eastern Canada going on a large meander in the Atlantic before turning NE and whacking western Europe including Britain.

Figure 3 The jet stream on 14 February from Netweather.

Netweather also have forecasts and animations of stratosphere temperatures. Figure 4 shows the picture for February 14 and I presume the area of deep blue over Greenland is the polar vortex that recently kissed the northern USA.

Figure 4 Stratosphere temperatures, 14 February 2014 from Netweather. The deep blue area over Greenland I presume to be the polar vortex.

I found the Netweather tutorial on stratospheric temperatures and the polar vortex to be most instructive:

Every winter the stratosphere over the North Pole cools, this begins when the sunlight can no longer provide the energy to heat the ozone. Without this energy, the stratosphere cools rapidly, creating a thermal imbalance with the warmer stratosphere further south. This imbalance creates a large pressure difference and combined with the Coriolis effect, creates a large strong jet stream, circumnavigating the globe in the stratosphere in an eastwards direction. This system is known as the polar night jet, and contained within it is a strong vortex – known as the polar vortex.

The polar vortex increases and decreases in strength depending upon how cold the polar stratospheric atmosphere becomes during winter. The colder the polar stratosphere becomes, the stronger the polar vortex – and vice versa. The strength of the stratospheric polar vortex influences the atmosphere below it in the troposphere.

To explain the enlarged and active polar vortex of 2014 a mechanism is required to cool the polar stratosphere that involves UV radiation and ozone. I once again fall back on the UK Met Office letter to Nature, Inesson et al (2011) that says this [1]:

Satellite observations of solar spectral irradiance in the ultraviolet region have been subject to uncertainty; the Solar Stellar Irradiance Comparison Experiment and Spectral Irradiance Monitor (SIM) instruments aboard the Solar Radiation and Climate Experiment (SORCE) satellite mission (2004–present) are the first designed to achieve accurate long-term measurements of the solar irradiance variations over the entire ultraviolet range. The 200–320nm part of the ultraviolet band contributes strongly to solar heating in the middle atmosphere, largely through ozone absorption. Ozone is itself produced through the interaction between ultraviolet radiation and oxygen, giving rise to potential positive feedback. SORCE observations made during the decline of solar cycle 23 reveal a remarkably strong decrease in mid-ultraviolet flux, some four to six times greater than previous spectral irradiance reconstructions. 

These observations are specifically for the decline of solar cycle 23 and we are now approaching the mid point of a very weak cycle 24 which is shaping up to be the weakest cycle for over 100 years and we need to wait for further observations to see if longer time scale variations in spectral output from the Sun may in part explain current behaviour of the polar stratosphere.

And so what about CO2? I have scanned IPCC AR5 Summary for Policy Makers and can find no reference to the jet stream in that report. Nor is there reference to the polar vortex. If the cause of recent events in the UK was so clearly linked to CO2 and global warming I would have expected that report to be provide a detailed explanation of the science that lies behind it.

Running the Netweather stratosphere temperature forecast forward to 27 February produces the picture shown in Figure 5. If that area of deep blue is the polar vortex then it appears to be heading Europe’s way in two weeks time if the forecast is accurate. I don’t know what implications this may have but I imagine that puddles and areas of standing water may freeze over.

Figure 5 The Netweather forecast for 27 February showing deep blue over western Europe.

Concluding comments

  • Alastair Dawson’s book chronicles 300 years of climate hell in Scotland (1600 – 1900) most probably extending to the whole of the UK, that was followed by the quiescent 20th Century that we have all come to assume is normal.
  • Normality for UK weather may in fact be much stormier, wetter and colder weather than we experienced during the 20th Century.
  • Jon Snow’s claim

    This country has never experienced anything like this before

    is nonsense and all the supposed experts lined up by the media to support this untenable view are clearly ignorant about UK climate history.

[1] Sarah Ineson et al (2011) Solar forcing of winter climate variability in the Northern Hemisphere Nature Geoscience PUBLISHED ONLINE: 9 OCTOBER 2011 | DOI: 10.1038/NGEO1282

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31 Responses to So Foul a Day and the Jet Stream

  1. burnsider says:

    The rainfall for the UK as a whole may not be overly remarkable (it certainly hasn’t been in Caithness, where I live) but it has obviously been just a tad wetter than usual in the south and south-west of England. Do you have some comparative rainfall values for the *worst-affected areas* rather than the whole country over the last couple of centuries? And, conversely, do you have comparative figures for Scotland and Southern England for the time period covered by ‘So Fair and Foul a Day’? (an interesting book!)

    It is not that long ago (?2010?) that the summer weather in England was monsoon-like, due to a very similar kink in the jet stream to the one which has piled all the low-pressure systems into SW England this winter. My recollection of the weather in the Far North then was that it was a bit cooler than usual but pretty dry (parts of the NW Highlands that year had 10% of their usual rainfall while England flooded due to the depressions heading on a more southerly track). It is quite likely that the overall UK rainfall was not particularly above average while the more local experience in the south was a bit moister than normal, to say the least.

    Probably what Jon Snow should have said is that ‘Devon and Cornwall have never seen anything like it, or not for a VERY long time’.

    • Euan Mearns says:

      Burnsider, the rainfall stats are available but take a huge effort to compile. I did this for temperatures a while back (chart below) and there is a surprising level of co-variance in T the length of the UK. I’d suspect that wet years in the S of England are also wet in Scotland – but you make a good point.

      So there has been a lot of rain in England but from what I can gather from TV reports and reading fragments on Bishop Hill is that the Environment Agency has deliberately engineered things in the Thames Valley and the Somerset levels to create flooding in some areas in order to protect others. This requires some corroboration.

      Another important factor in early January when a lot of the damage was done was anomalous strong lunar tides. See link to Clive Best below. High tide + storm surge + strong westerly wind was a potent force to cause damage. Its possible in Somerset that this dumped some sediment in “the wrong place” impacting subsequent drainage from this basin that is only a few meters above sea level.

      Figure 5 Tmax, 5y running averages for 23 UK stations.

      • burnsider says:

        I’m not sure that temperature tells the whole story, although the variations show good correlation across the country. I remain curious to know if rainfall correlates with temperature, both in the absolute sense and relatively across the country. After all, arctic sea ice cover continued to decrease and the ice that remained continued to thin (according to US Navy data) while global temperature changes appeared to pause.

        I did a bit of data digging in the aftermath of the extreme rain in the Far North in October 2005 (rainfall was not extreme elsewhere that time in the UK as far as I know) to see if information was available which would allow a judgement to be made as to whether that kind of extreme weather was becoming more frequent. It was at that stage that I found that the met Office had a network of weather stations in the north collecting rainfall data, some going back a long time (the good news and no surprise). The bad news was that they wanted significant sums of money to compile and part with the data for specific regions which put a stop to further data digging. Perhaps one of your other correspondents has access to the relevant data, or a summary?

        The underlying issue with the recent weather is not whether it was the most extreme, nationally or locally, but whether it is likely to become more frequent. Simple physics suggests that a warmer ocean and atmosphere is likely to lead to more extreme winds and rainfall purely due to the increased energy and water content of the atmosphere. As to whether the recent spell weather was in any way related to warming of any sort, whether natural or anthropogenic, that remains an open question.

        BTW, I was a long-running ‘lurker’ on TOD – I think I maybe posted once – so it is good to see some of the old familiars popping up again 🙂

        • Euan Mearns says:

          Burnsider, you can download Met Office station data here:

          Wick airport is closest to you, October 2006 stands out as a major anomaly on rainfall. It is actually extremely time consuming to begin and compile all this data. 5 different data sets per station, over 100 years of monthly records in some instances, dozens of stations.

          The physics of storminess is a complicated nut to crack. Warmer atmosphere and more water vapour may lead to more thunder storms which is the atmosphere’s natural way of keeping temperatures stable – convecting heat to the tropopause. Convection remains the principal way of the atmosphere losing heat, a point that is all too often forgotten.

          It is not at all obvious though that a warmer atmosphere should lead to a greater incidence of cyclonic storms that we have just been exposed to. They tend to be driven by temperature contrast between tropics and poles. The tropics maintain very uniform temperatures while the poles have warmed reducing that contrast.

          Alastair Dawson’s book was in fact commissioned by the Scottish Government in the wake of that accident in South Uist where a family were drowned by the storm on the causeway. What he found was that it was much stormier in the past and it was not that storm that was unusual but more the quiescent nature of the 20th Century in Scotland. What we are seeing now may well be attributed to climate change, but most likely the wheel of the natural cycle turning, though I concede that there can be an anthropogenic overprint. The climate science view of the world is that past climate has been uniform and any deviation from that uniformity must therefore be down to Man. This wouldn’t matter a jot if it were not for the fact that our energy infrastructure is being overhauled and destroyed at great cost to the common Man in a futile effort to stop a process that in my opinion is dominated by natural causes.

        • Roger Andrews says:


          You are curious to know if rainfall correlates with temperature across the country. It doesn’t:

          • burnsider says:

            Thanks Roger – a convincing set of data. I wonder if the frequency of extreme events (say 2 or 3 sigma from the mean monthly rainfall) or the magnitude of any year’s highest rainfall event correlates with mean annual temperature over the 250-year period?

          • Roger Andrews says:

            Burnsider: Just ignore all the points in the middle and look at the points around the edge – these are the “extreme” rainfall and temperature events. They don’t correlate either.

    • Joe Public says:

      Paul H today has a complementary posting “Southern England Much Wetter In 1929/30”

  2. Glen Mc Millian says:

    I used to post comments frequently at The Oil Drum and some people here may remember me as Oldfarmermac.
    There is an article at New Scientist behind a paywall unfortunately that leads me to believe that under ground coal gasification is about explode into a truly major industry barring it being outlawed or it failing to work.

    The impression I get is that UCG has already proven to be technically and most probably economically viable to the satisfaction of the investment community.

    The implications of the widespread utilization of this technology are staggering to say the least from any point of view.

    Hopefully there will be some serious attention focused on this issue in the near future.

    • Euan Mearns says:

      Hi Mac, glad you managed to post a comment at long last. Despite my climate sceptical views, I am actually cautious on encouraging / enabling Man to burn everything he can. CO2 has risen from 260 to 400 ppm – a tiny increase. If this tiny increase really is responsible for climate chaos today then we really are in deep sh*t. I am simply not aware of any convincing evidence that any of the variability in climate observed today has to be attributed to Man. At the same time I am not in favour of enabling energy policies that take us towards 1000 or 2000 ppm CO2 – and that is where UCG may take us. This would only be safe with categorical evidence that CO2 had virtually zero impact on green house energy balance and / or that CO2 increase really has nothing to do with combusting FF – points I am unsure about. With an equilibrium climate sensitivity of 1.2 we see 1.2˚C warming at 520 ppm, 2.4˚C at 1040 ppm and 4.8˚C at 2080 ppm. So I think it makes sense to transition away from conventional fossil fuels towards nuclear power at a leisurely pace. And to leave the non-conventional in the ground.

    • Luís says:

      Hi Mac. You can be sure there were folk thinking like you in the USSR in the 1950s. Marketing the H2 CO mix that you get from UCG at prices below natural gas is an immense challenge, to say the least.

  3. lapogus says:

    Euan – I have not had time to read through this in detail, but just to confirm that the clustering of wet years is well known by hydrologists – D. Gilvear at Stirling University in the 1980s and 1990s, did a lot of research on the historical floods Tay and Forth, going back to the 13th Century (Perth was destroyed by a flood in 1210). Like buses it seems that severe floods often come in threes, the most recent example of the Tay flood in 1993 which was preceded by an equally severe flood event in the western catchment in 1990, and there was also an intermediate flood event in 1989. The flood in 2006 has been the largest since then, when the flows exceeded 1993 levels in the western catchment. SEPA boss Curran likes to think all these recent floods are as a result of AGW, but people have short memories, and none of the extreme floods and weather events we have experienced in the last 50 years are unusual or unprecedented. A quick look at confirms this.

    As an aside, thanks for the head up on Dawson’s book, I will be getting it. Does he cover the December 28th 1879 storm which blew down the Tay Bridge? I believe the severity of the 1879 storm has been overlooked, mainly because the failure of the bridge was (rightly) blamed on its design. But the same night, forests in Perthshire were flattened, and also, a house on the (sheltered) east coast of Tiree was washed into the sea. As Tiree is over 120 miles from Dundee, and it is unlikely that storm track was due east, that must have been some storm.

    • Euan Mearns says:


      Shortly after Christmas, on Saturday 27 December 1879, a bad storm swept across Lewis. It was recorded as force 12, with winds from the SW. By the next day, the winds had moved roudn to the NW but were still measuring force 10…….

      I have a cottage in Caputh (my deceased parents retirement home) that is on the flood plain of the Tay, so I have more than passing interest in the events you describe. Paddled from Loch Tay to Caputh last year. 8 hours with only 3 pub stops 😉

      Dawson is a great climate historian and sceptic, but extremely mild mannered and modest.

  4. burnsider says:

    I don’t think any climate scientists were claiming that the recent wet weather in the deep south was caused by climate change or global warming or whatever as you can’t say much from a single year’s data (I heard one climatology Professor saying exactly that on the Radio 4 ‘Today’ programme about a week ago). I also don’t think that climatologists are saying that the past climate was uniform as the climate record says clearly that it was not.

    It is likely that the variation in weather from year to year at any one site or in any one country is normally distributed, so the probability P of a record event in a series of n years, rainfall in the current context, is given by the sum of the Harmonic Series:-

    P(n) = 1 + 1/2 + 1/3 + 1/4 + 1/5 +…..


    Some values of the sum (= number of expected record years) for various numbers of years:-

    n(yrs) 1 5 10 50 100 500 1000
    P(n) 1 2.28 2.93 4.50 5.19 6.79 7.49

    Thus in a 50-year interval, you would expect between 4 and 5 years to have rainfall higher than anything measured to date in that interval, in a 500-year interval, between 6 and 7 years to have higher than any other and so on. This would obviously extend to temperature, wind speed or any other relevant parameter for which there is a long and consistent time-series of data. If the number of record years per interval is changing with time, it follows, the underlying distribution of weather events is also changing.

    As a chemist (now retired), I am well acquainted with the work of the 19th century chemist Svante Arrhenius, which included the first considation of the role of carbon dioxide in terms of its effects on global temperature. For info, I subscribe to the mainstream scientific view that the increase in atmospheric carbon dioxide since the industrial revolution has had and will continue to have an effect on the global climate. The location, nature and extent of the changes is still being teased out from the data, but the application of the scientific method will result in the best possible understanding of the situation, as it always has (eventually, in some cases!!) in the past. If carbon dioxide is actually causing the climate to cool or is having no effect whatsoever compared to natural variations, this will eventually be proven from the data and AGW will be consigned to the dustbin of history, along with Phlogiston Theory and Ptolemy’s Epicycles.

    Alas, I doubt that this will happen. I’m afraid I am a gloomy old sod, and I firmly believe that pretty much every gram of fossil carbon in whatever form that can be extracted economically will be extracted and most of it will be converted to carbon dioxide and end up being released to the atmosphere. I used to work in the nuclear industry, but I don’t believe that nuclear power is any more than a very modest part of the solution to the looming energy/climate dilemma(s). As to what the best solution or solutions might be for the greatest number of people, who knows? Plenty have been suggested, but most are very hard for politicians to stomach or try to sell to an electorate who will just vote for the other guy who promises business as usual.

  5. lapogus says:

    Burnsider – Slingo has used the phrase ” consistent with” and that has been enough for the media, politicians and activists to run with the ball. But Slingo is on thin ice – see

    Why be so gloomy? The Stone Age didn’t end because they ran out of stones, and future generations will thank us for leaving them all the thorium. I don’t agree with everything he argues, but maybe you should read some Matt Ridley or have a gander at his videos for an antidote – e.g. – more at

    I have considerable doubts whether CO2 has had anything to do with the late 20th Century warming, which more likely is just a consequence of some multi-decadal natural variation, on top of the continuation of the long slow thaw from the Little Ice Age. I also think spurious adjustments for UHI and station selection will also have had a part to play. Indications from the last 5-10 years suggest to me that the planet,or at least the NH, is beginning to cool again, time will tell.

    • burnsider says:

      I confess to being suspicious of many secondary sources as they, like documentaries and newsreels, have been edited and often reflect the views or agenda(s) of the writers or those commissioning the production. When I was working as a chemist, I went back to original reports whenever possible. With this in mind, I did a little bit of digging back to some original work/data (I know this is often difficult or expensive due to paywalls)

      As ever, much brighter people than me have already addressed many of the issues I wanted to understand above. I would commend the Met Office report

      on the recent weather pattern, which contains a clear and well-referenced description of the many factors which drive our perennially variable climate. Matters like frequency and intensity of extreme events are covered. In the UK, the Met Office has access to the largest and more consistent weather data set, bar none. While it could be argued that the Met Office has an agenda and may have edited the data to fit this, it is hard (to me at least) to see why they would want or need to do this. Thus, I have assumed that original work such as the above report is at least as reliable as any other original work referenced elsewhere in the scientific literature.

      The Met Office view on the recent weather:-

      “The exceptional duration of the stormy weather and the clustering of deep depressions has been a notable feature of this winter. Rainfall records were broken in both December and January. Scotland had its wettest December since records began in 1910. In southern England,January was the wettest recorded since 1910, and the statistics suggest that this was one of, if not the most, exceptional periods for winter rainfall across England and Wales in at least 248 years. The two-month total (December + January) of 372.2mm for the southeast and central southern England region is the wettest of any 2-month period in the series from 1910.

      A particularly exceptional aspect of January 2014 has been the number of days with rain across southern England, which far exceeded anything previously recorded for January. Overall there have been very few dry days since 12th December. This continuous sequence of rain events led to increasing saturation of the ground so that widespread flooding became inevitable when the major storm of 5th and 6th January arrived over the UK. The Thames, in particular, recorded some of the highest flow rates ever measured at this time of year. In January 2014, the Environment Agency Thames Barrier was raised on 13 consecutive times to protect people and property as high fluvial flows and high spring tides coincided. Rainfall continued to be well above average through January, giving little respite for areas already affected by flooding especially in southern England, and notably Somerset.”

      I can’t post the accompanying Figures from the report, alas.

      The possible impact of climate change was considered:-

      “In seeking to answer questions about the impact of climate change on severe weather, there are two distinct steps to be taken. The first is to detect a change in either the frequency or intensity of storminess or rainfall events that is more than just the natural variability in UK weather. UK weather is notoriously volatile and so detection is particularly challenging. Severe storms have always affected the UK and are documented in many historical records. The intensity of recent storms is unusual, as the climatological records discussed earlier indicate, but not necessarily unprecedented.”

      along with the frequency and intensity of storms:-

      “Although the number of strong winter cyclones has not increased since 1871, the mean intensity has. Notably, for very strong cyclones, the mean intensity has increased significantly. A more comprehensive study of storms affecting the UK is needed to explore these findings in more detail, but the current evidence does suggest an increase in storminess. The persistence of the recent storminess is unusual, and although clustering of storms is quite common, the continued run of deep depressions, through December, January and on into February, is not. It is this continued run of storms that has created the exceptional flooding conditions experienced in the Somerset Levels, for example.”

      The report concluded:-

      “In terms of the storms and floods of winter 2013/2014,it is not possible, yet, to give a definitive answer on whether climate change has been a contributor or not. The climatological context discussed earlier was unusual, with the Atlantic jet stream being more intense and reaching further back into the tropical East Pacific than normal. Those factors in themselves would allow warmer and moister air to enter the storm systems. It is also the case that the sub-tropical Atlantic is now warmer than it was several decades ago and that too would act to enhance the moisture content of the storms.

      More research is urgently needed to deliver robust detection of changes in storminess and daily/hourly rain rates. The attribution of these changes to anthropogenic global warming requires climate models of sufficient resolution to capture storms and their associated rainfall. Such models are now becoming available and should be deployed as soon as possible to provide a solid evidence base for future investments in flood and coastal defences.”

      I found a handy visualisation of NASA data on global temperature anomalies 1951-2011:-

      The significance is the ‘flattening’ of the normally distributed temperature curve combined with the shift of the mean to a higher value as successive time intervals are considered. The raw data for global land and ocean temperature anomalies is available at

  6. Luís says:

    This is a great post Euan. A strong and southerly jet stream is a feature of cold weather, when the temperature differential between the pole and the equator swells. That is why it is not present in the IPCC report, as the global temperatures increase the jet stream should become weaker and northerly.

  7. Ulric Lyons says:

    “You are curious to know if rainfall correlates with temperature across the country. It doesn’t:”

    Yes it does, but you won’t see it in the annual totals as the response reverses from summer to winter. Warmer than normal in winter tends to be wetter than normal, and cooler than normal in summer also tends to be wetter than normal. On the short term in the annual totals, there is a slight bias for more rain in cooler years.

  8. Euan Mearns says:

    Ulric, thanks for this, your logic seems sound. Yet another warning on the care required in slicing and dicing data. I think Roger is using CET data – I’m not familiar with it, and am therefore uncertain if he can plot seasonal data. My own experience doing this is exponential spread sheet expansion when you get into monthly data series.

    • Roger Andrews says:


      When analyzing data for trends it’s normal procedure to remove the seasonal cycle before starting. However, since the question of the impacts of the seasonal cycle has come up I’ve prepared a number of graphs that show what we get when we leave it in. The graphs match up the Hadley Central England monthly and seasonal temperatures and the Met Office Central England monthly and seasonal rainfall totals since 1873, and hopefully will be self-explanatory.

      • Ulric Lyons says:

        That is not seasonal rainfall totals in your graph, just sum the months, don’t average them. Autumn has contrary signals as Sept behaves as summer does., but Nov behaves as winter does. Spring behaves as summer does from Apr onwards.

      • Euan Mearns says:

        Roger, I’d say that in JJA, warmer summers have less rainfall – makes sense for the UK – yes? I saw the same thing between temperature and cloud cover. From memory, all the correlation was in the summer months. One thing to do with your large scatter plot is to colour code the seasons (or months) and a pattern may emerge.

        Not suggesting you actually do this since it takes time, only if you have a spare moment between tequilas 😉

  9. Ulric Lyons says:

    You can select monthly and seasonal from 1910 here:
    It shows a recent trend of wetter summers and drier winters, which is what should be expected with cooling. This winter stands out as an exception to the trend.

    Years when annual rainfall for England and Wales was greater than 1000mm, are more likely to be colder than the average:

    • Roger Andrews says:

      “Years when annual rainfall for England and Wales was greater than 1000mm, are more likely to be colder than the average:”

      Central England temperatures vs England & Wales rainfall since 1766:

      62 years with >1000mm rainfall, mean temperature = 9.34C
      186 years with <1000mm rainfall, mean temperature = 9.31C

    • Roger Andrews says:


      Percent of years with >1000mm rainfall colder than average = 46.8
      Percent of years with <1000mm rainfall colder than average = 55.4

      • Ulric Lyons says:

        With a long term average temperature yes, but not a moving average.

      • Ulric Lyons says:

        With a long term average yes, but not a moving average.

        • Roger Andrews says:


          I think the time has come for you to back your comments and claims up with some actual data.

          • Ulric Lyons says:

            Taking a more recent period where there has been little temperature change
            on CET, such as 1900 to 1987:
            rainfall >1000mm in years with above average annual temp of 9.4°C = 7 years
            rainfall >1000mm in years at average annual temp of 9.4°C = 5 years
            rainfall >1000mm in years below average annual of 9.4°C = 11 years.

  10. Roger Andrews says:

    Euan: That’s what the four small XY plots in the graphic I posted yesterday show – warmer temps = more rain in the winter and less in the spring, summer and autumn. However, this makes no difference to my conclusions re the Met Office analysis.

Comments are closed.