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PhilipEden

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  1. Not The Long Range Forecast indicates 10.9°C Philip
  2. 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
  3. 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
  4. An early steer on Not The Long Range Forecast suggests 14.5°C Philip
  5. 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
  6. 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
  7. 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
  8. 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
  9. 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)
  10. 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
  11. 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
  12. LOL ... merely a device for separating close calls. Philip
  13. The Not The Long Range Forecast mean temperature comes out at 17.1°C, if anyone's interested. But, remember, it's NOT a forecast ...! Philip
  14. 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
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