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PhilipEden

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Posts posted by PhilipEden

  1. It's stayed at 16.9 for the 1-26. I agree with Anti-Mild that 16.7 looks the lowest figure likely now - might even be 16.8 if Saturday is warm.

    For those who are interested it was 16.94 after the 25th and 16.89 after the 26th. Some may also be interested that my Hadley CET emulation is running about 0.1degC higher than the Manley this month.

    Philip

  2. Yes, Paul that is right if we look at the Manley series but I point out that series does have the caveat "provisional" attached to it, so when we quote those figures we should really be say "provisionally" Splitting hairs maybe, unfortunately they are unofficial figures, certainly until "provisional" is dropped.

    Even the Manley series has got its problems, as about the first 40 years of that series is only as quoted to X.5 and Y.0 whilst the rest is to 0.1, so we have to be wary of that fact as well and so it puts some doubt when we quote those early figures.

    The question I have to ask is did Gordon Manley keep figures for 1974 to 79, he died in early 1980. He must have done, what with the winter of 1974-75, summer of 1976 and winter of 1978-79. The Met Office took guardian of those figures but when? In 1980, after he died or before or well after his death?

    Kevin, Gordon Manley's published series ended at the end of 1973. He may well have kept a watch on the figures after that, but he didn't publish; he was an old man by then anyway.

    The MO did not routinely publish a monthly CET until well into the 1980s, although the Synoptic Climatology Branch (as it was then) probably produced a figure in-house. It was not regarded as important - indeed Manley was often vilified inside the MO as being a "geographer" and therefore not a proper scientist.

    When the MO finally did get around to publishing a monthly CET, at first they used all sorts of different methods to achieve the figure. Quite how and why they settled on the tri-polar scheme that forms the basis of the present Hadley calculation I have not been able to discover.

    HTH, Philip

  3. I'm not sure about the Manley figure myself- it might be because of locally above-average temperatures at the stations, or it might be an error in calculation that would be corrected shortly. I notice that the temperature graph seems to suggest a near-average temperature rather than 1C above.

    We'll probably find out in a couple of days' time in terms of what the value is.

    Eeek! 33.5 divided by 2 is not 17.7, Philip. It'll be corrected tonight. Meanwhile I have to come to terms with learning that I am not infallible. Back to the cricket, I think.

    Philip

  4. hi Philip

    Of course, some errors can be avoided (eg not using a coastal site for an inland temperature index) which brings us right back to the reason for creating the "Manley" series.

    The original paper by Manley, I refer to it in an earlier post, explained how he arrived at what he called the Midlands index. It took account of a disparate set of data from very different sites. Two were definitely coastal =Edinburgh and Plymouth, along with data from Exeter by a tidal river and the London data came from various sites most by a very large tidal river.

    John

    John, he explains that that was to extend the index back before 1771 when suitable inland sites were sometimes unavailable. From 1771 onwards he uses only inland sites (he actually specifies "inland" in the initial abstract) and from 1815 onwards he uses only Oxford and the Lancashire Plain. This is the core of his work.

    Philip

  5. The key point to note here is that there is ALWAYS going to be an error in calculating an average AS IF it were two d.ps. when the source data is only at one d.p. and that error can, in extreme, approach +/- 0.05. When judging records that have been beaten only very marginally that error might actually account for all of the apparent margin. This July comparisons are a case in point, and perhaps in the desire to see records broken we miss the point: it was still an exceptional month.

    Statistical error is only one of the various errors that users of climatological records have to contend with. There are also calibration drift errors, observational errors, minor site characteristic changes, and others, as well as errors which may be introduced by enforced changes of site even after the new record has been normalised. That is why I quoted + or - 0.2 degC which is the widely-accepted figure for this type of climatological temperature index. Of course, some errors can be avoided (eg not using a coastal site for an inland temperature index) which brings us right back to the reason for creating the "Manley" series.

    Philip

  6. Whilst true Philip, we surely need to work with a viable baseline and the fact is that since 1659 the baseline has been calendar months - something we can all recognise. Or is it possible to breakdown the series prior to 1974 into other 30-day periods?

    No problem, Richard ... I think you've slightly misunderstood where I'm coming from, which is probably down to my lack of clarity. Of course we have to stick with the monthly values. The point I was trying to make was simply that we have had hotter spells before, in the recent past, too. They just didn't coincide with the calendar month.

    Philip

  7. A point made by someone else I think Philip, but shot down in flames by someone, who shall remain nameless because I'd hate to upset Dawlish.

    I don't quite see the fascination in the CET, but then some people don't find hinge collecting exciting either, so live and let live I imagine.

    Indeed you are right, OO-N. But I note that you still read the thread .......!

    Philip

    (PS If anyone is wondering, I don't use smileys)

  8. Hi. No!

    The problem is all to do with which stations continue Manley's stations most accurately. In that sense it's like the boxing problem you mention. But the almagamation solution wouldn't make it any more accurate. The problem it seems to me does actually lie with the Met Office, and this is probably the point where John and I lose our love-in. They have clearly introduced stations e.g. a coastal one, which is nothing like the original series. The real challenge is that the Met Office should stop calling their Hadley series the CET. But that's controversial, to say the least. Bear in mind that I'm normally a big fan of theirs, and I love the work Hadley does ... but it isn't the CET imho.

    A few small points. As several people have said, no-one should get hung up on this; the differences are not earth-shattering or life-threatening. I choose to quote to two decimal places merely to enable a user to separate close calls ... remember, too, that the CET is a temperature index, a statistical device, not an actual temperature. In any case the values should probably carry plus-or-minus 0.2degC error bars.

    I do have a gripe with Hadley, but only over method. They seem disinclined to engage on this topic, though. The MO press office will naturally spin in favour of their own data, which, perhaps deliberately, perhaps not, will appear as spinning against me. Could I care less? Well, probably. But to suggest (c.f. the Metro) that their results are better because they use five (sic) stations and I use two is not only wrong, it's infantile.

    A more important point which I made before, but nobody (forgive me if I've missed it) seems to have picked up on it: calendar months, useful as they are for characterising the climate, are abitrary time periods. There is roughly a 3% chance of the hottest 30-day period of the year coinciding with a calendar month. Hot as July was, it was not as hot (nor as sunny) as 30-day periods straddling June/July 1976 or July/August 1995.

    Philip

  9. Now for the argument, is that Manley or Hadley, or is it both. No mention of either so I would assume, although I may be wrong, that it refers to the Manley data.

    Anyone care to comment?

    John

    Given the extreme interest in July, I thought it might be useful to post the synoptic overview which I normally only put out on uk.sci.weather. It might answer some questions but it will undoubtedly provoke many more. I note that Hadley's first attempt at a CET value is pretty much the same as what I calculated using the same stations that they use. I wouldn't plan to post this every month unless there was a particular demand for it.

    <QUOTE>

    In spite of a relatively cool and cloudy episode between

    the 5th and the 13th, hot and sunny weather dominated

    July 2006 such that many long-standing monthly records

    for temperature and sunshine were broken from sites

    anywhere from southeast England to central Scotland.

    Although widespread thundery activity lifted national and

    regional rainfall figures out of the 'exceptional' range, there

    were a few areas that entirely escaped the storms and

    ended up with a remarkably dry month. The outstanding

    nature of July's weather could largely be explained

    synoptically - for the combination of high pressure and

    frequent southerly winds it was a July without parallel -

    but that, of course, leaves the question what forcing factors

    might have been involved in creating those particular

    synoptic characteristics.

    More is available at:

    Charts: http://www.climate-uk.com/monpre/0607.htm

    The Monthly Review should appear very shortly at::

    http://www.climate-uk.com/monthly/0607.htm

    Graphs: http://www.climate-uk.com/graphs/0607.htm and

    http://www.climate-uk.com/graphs/200607.htm

    Not The Long Range Forecast should be up on the 3rd at:

    http://www.climate-uk.com/page4.html

    The mean sea-level chart shows that the Icelandic Low located

    southwest of Iceland at 1007mbar, with another centre of 1007

    mbar over northern Quebec and one of 1008 mbar in the Russian

    Arctic. The Azores high was again displaced to the west of its

    usual location and was more intense than usual at 35N 40W,

    1027mbar. A further high centre was located over Germany at

    1020mbar. The mean flow over the British Isles was SSWly

    (SSE-ly in East Anglia and the Southeast) with an anticyclonic

    bias.

    The main feature of the sea-level pressure anomaly field was a

    broad zone of above-average pressure covering practically the

    entire European mainland, whereas pressure was near or below

    normal over virtually the whole of the North Atlantic Ocean,

    Greenland and eastern Canada.

    The main centres were:

    -7mbar over mid-Atlantic (55N 29W)

    +7mbar near Stockholm

    +2mbar near Bermuda

    -4mbar east of Novaya Zemlya

    Over the British Isles pressure anomaly ranged from -1mbar

    along the west coast of Ireland to +3mbar in Shetland. The

    anomalous flow was markedly SSEly.

    CET (after Manley) 19.85°C (+3.4 degC wrt 1971-2000)

    making it the warmest July since 1983 by this measure

    CET (after Hadley) 19.75°C (+3.2 degC) making it the

    warmest by this measure since the record began in 1974.

    There have, however, been warmer 30-day periods straddling

    two calendar months, for instance in Jun/Jul 1976, Jul/Aug 1995,

    and Jul/Aug 1997.

    E&W Rain (provisional): 38.0mm ( 66% of 1971-2000 mean)

    making it the driest June since 1999, and it ranked 16th

    driest in the last 100 years

    E&W Sunshine (prov): 302.5 hr (151% of 1971-2000 mean)

    making it easily the sunniest July since records began

    in 1881 (bear in mind strict comparisons cannot be

    made since the change from CS recorder to KZ sensor),

    and probably also the sunniest calendar month of any name

    on record.

    There were sunnier 30-day periods straddling two calendar

    months, for instance in Jun/Jul 1976 and Jul/Aug 1995.

    CScotT: 17.1°C (+2.2 degC)

    ScotRain: 45.4mm ( 73%)

    ScotSun: 205.0hr (129%)

    NIT: 16.9°C (+2.1 degC)

    NI Rain: 58.6mm ( 85%)

    NI Sun: 221.9hr (145%)

    Rainfall totals ranged from 128.6mm at Inveruglas (Argyll)

    to 3.1mm at Hunstanton (Norfolk) and 4.2mm at Skegness

    (Lincs).

    Percentages ranged from 209 at Brize Norton (Oxon) to

    just 6 at Hunstanton.

    Sunshine totals ranged from 343.4hr at Shanklin (IoW) and

    342.6hr at Eastbourne (Sussex), both presumed CS recorders -

    to 137.4hr at Stornoway (I.o.Lewis), a KZ sensor.

    Percentages ranged from 177 at Scarborough (N.Yorks)

    and 176 at Ross-on-Wye (Herefs) to 105 at Stornoway

    (I.o.Lewis)

    <END QUOTE>

    Philip

  10. That's a staggering increase on the previous max, particularly in such a large data series. Certainly no hyperbole in your use of "astonishing". Right, must get back to the wisened souls on "Ice Age Now".

    Will have to have words with him about that! I guess it depends on the precision of the instrumentation being used, but as 1/10th degrees are the standard reading for most (if not all) sites, then no less than the same interval should, strictly speaking, be used for quoting an average of the readings, otherwise a precision is implied that may not actually be real.

    Philip, are you using probes sensitive at 1/100th C now?

    LOL ... merely a device for separating close calls.

    Philip

  11. I think the only way to stop this becoming another merry go round on what should be done is to get Philip to post his ideas. I'm pretty certain they will be along the same lines as my explanations.

    John

    OK, as requested ...

    People can work out their monthly mean whatever way they like. But if you do not conform to a standard then those figures will only be of interest to yourself ... they'll be largely useless and meaningless to anyone else.

    The standard, for historical reasons, is the average of the mean monthly maximum and the mean monthly minimum (as recorded at 09z) as John and others have explained.

    The main reason is simply that, before AWSs arrived, most climatological stations were read only once per day, at 09z, and that was the case for over a century. It's only in the last 10 years or so that relatively cheap and reasonably reliable AWSs have provided means of logging data throughout the day.

    The mean monthly temperature, as described above, is of course only an approximation to the true mean, but the main use of these figures is for comparing one month with another, and one site with another. Consider it as a monthly temperature index if you like, rather than a true mean temperature.

    If you think it's also important to have the closest approximation to a true mean temperature by integrating your hourly or 10-minute or 5-minute loggings throughout the month, then by all means do so. It's not forbidden to have the standard monthly temperature index AND an integrated mean temperature. Do both.

    But for purposes of geographical and/or temporal comparison, use the standard.

    Philip

  12. :) Ah, ok!!! I was trying to work out if the sunshine totals thing was part of it!

    If Philip's around I'd love to know if he oculd have a stab at guessing how far behind the E&W figure he reckons the Areal sunshine figure is. His figure looks likely to pass 300 hrs which is pretty spectacular really.

    My July mean is 4.6% higher than the MO July mean. Over the year, most months are between 5 and 10% higher (with the bigger percentages in winter). My sunniest calendar month on record was June 1957 with 302h, but there have been higher 30-day totals ... in fact you can see from one of this month's graphs that the period 29 June to 28 July was higher, 305.6h in fact. I believe the highest 30-day total was 22 June to 21 July 1976 with over 310 hours.

    Philip

  13. Hmmm, Mr D, I'm not so sure....at least in normal British usage.

    The general rule for proper names ending in a consonant and a -y is to pluralize with an -s: thus "The Kennedys are an interesting family" or "I know a number of Sallys". It becomes confusing with the months of the year, as they have an odd, only semi-proper status - and certainly "Januaries & Februaries" is the norm (though the Cambridge estate agent is called "Januarys" and there's a band called "The Februarys"!). But there is also an overriding rule with plurals: that if any rule-based pluralizing causes confusion, then the rule may be broken...and "Julies" is certainly very confusing. In any case the Oxford English Dictionary seems quite clear on the matter: July n. (pl.~s).

    I humbly submit that it should be "Julys" :) !

    I largely agree, except for Jans and Febs. All publishers I have worked with, and as far as I know all Fleet Street newspapers, will use Januarys and Februarys as well as Julys. The Guardian embarrassed itself in the 1980s by using a massive front-page headline referring to "T

    I largely agree, except for Jans and Febs. All publishers I have worked with, and as far as I know all Fleet Street newspapers, will use Januarys and Februarys as well as Julys. The Guardian embarrassed itself in the 1980s by using a massive front-page headline referring to "THE TWO GERMANIES". It was after that, and a lot of internecine ribbing, that our national newspapers agreed on the -ys formula for all words beginning with a capital letter and ending with a "y".

    Philip

  14. Yes, Philip Eden was also quoted the same thing in today's Metro...

    What I actually gave the reporter was "... will probably end up at 19.9°C, so if it does break the record it will do so by the merest fraction." You can never guarantee how these quotes will turn out. <gallic moue>

    Philip

  15. Indeed SB. Interestingly I think it's actually 16.15C rounded up, so I wouldn't be all that surprised if, despite the heat today, Hadley comes in at 16C or 16.1C with Manley at 16.2C. It would be interesting to hear Philip's views on this.

    Putting in sensible estimates for today brings the Manley CET up to 16.25 ...

    BUT ...

    ...and it's a big 'but' ... my calculation for the Hadley CET is appreciably lower this month (Stonyhurst was relatively low, and a few people have noted that parts of Lancashire have done rather poorly at times this month). It comes in provisionally at exactly 16.00.

    Philip

  16. Well interesting days ahead. A warm/hot weekend and then ... what? Bit of unsettled weather for a day or two with high pressure never far away to the west. For any of these 4 to fall will need the high pressure coming over the UK I think, which I still think is the likeliest scenario. No. 2 - sunniest June does look vulnerable to me. With 14 days gone the sunshine level was just under 169 hours. That leaves 114 to go in 14 days. This is by no means out of reach, but it does of course entirely depend on, er, sunshine! http://www.climate-uk.com/graphs/0606.htm

    Eeeeeeek! Hold your horses ... my sunshine series is different from the MO's. (The reason is that, unlike the CET and EWP, they produced their new EW sunshine figures relatively recently, long after I started mine, and I wasn't about to scrap all my hard work just to copy theirs). Broadly speaking, my figures are somewhat higher than theirs. If you look at

    http://www.climate-uk.com/graphs/200606.htm

    you will see that the June record (1901- , not 1929- ) stands close to 300 hrs (in fact it's 302 hrs). So a new record will be harder to achieve.

    Apologies for any confusion.

    Philip

  17. Provisionally, the Manley CET comes out at 12.24°C, and my estimate of the Hadley CET at 12.45°C ... quite a large difference. On the other hand, my estimates of Hadley over the last three months have been slightly high. I may not be able to confirm the Manley figure for quite a while ... and the website may not update quite as quickly as usual this month as my time and energy are required elsewhere just now.

    Philip

  18. Well the Manley CET has leapt to 12.8C today http://www.climate-uk.com/

    That's a rise of 0.3C in 24hrs, and we are now 2.6C above average. With more of the same tomorrow and Friday we might be 3C above the adjusted average by the weekend.

    It's going to need a really significant synoptic shift to correct this. As we all know, that can happen. But there's just nothing cold, or even cool, really in the CET zone for another week.

    Sorry, that was an error ... 12.6 is the correct figure (actually 12.64)

    Philip

  19. Nay probs Dave. I got something totally wrong with you the other day about temps - it's good to admit these things sometimes! Actually, I do like that Dundee site -lots of useful stuff there.

    It's interesting to see that Philip reckons Hadley is 8.72C. Does this not mean a revision will indeed happen in due course? Philip, what do you reckon?

    Well, when they produced their figure this early before, back in early-Jan, it seemed to be a mistake and was quickly withdrawn. The MO certainly won't have completed their Quality Control procedure this early - it is after all the first working day after the end of the month (it usually takes 5 or 6 days) - and I know that there were a handful of missing observations for the stations that they use.

    I'm not very good at predicting Hadley's activities, but I reckon the figure on their site will disappear very soon, and come back again, hopefully revised upwards, later in the month. I still fully expect their December figure to be quietly revised in due course ... however hard I try I cannot see where that 4.4 comes from.

    Philip

  20. Something's going on with my friends up the road ... they have ALREADY posted up the official April Hadley figure and it's 8.5C which is 0.1C below Philip Eden's Manley figure.

    http://www.meto.gov.uk/research/hadleycent.../HadCET_act.txt

    LOL ... the last time they put a figure up this early (the Dec CET in early-Jan) it disappeared two days later and came back as a different figure later in the month.

    FWIW, the final Manley CET is 8.69, and my estimate of the Hadley CET is 8.72

    Philip

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