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Stratos Ferric

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Posts posted by Stratos Ferric

  1. Could still go either way this month, and GFS is continually imprecise when it comes to picking major changes in trend. However, on the basis that in the best of times three cold months was a rarity - and we no longer inhabit the "best of times" - I'd take a punt on the upwards side.

    4.2C

  2. Quite a change since my last update. As the narrative in the attached suggests, it's hard to place this month properly in context. Assuming a month end mark of 1.4C, then by recent standards it's exceptionally cold. Taking the deviation from the running ten year mean for the month (= -3.8C) then it ranks 4064/4106, i.e. just about in the coldest centile (1%) of all months since 1668. Feb 1986 (-4.5); Dec 1981 (-5.1); Jan 79 (-5.1); Jan 1963 (-5.6); and Feb 63 (-4.5), in recent times all came in colder on this measure, but they set in context that, relatively, this month is much colder than it has been in absolute terms.

    Amongst Januaries alone, it would rank 329/343 on the same anomaly basis. Expand the reference period to 30 years and the rating drops to 322/343 - reflecting the impact of recent warming on the comparative baseline.

    This month will also end the record breaking spell without a sub 3.0C month (ditto sub 2.0C, though almost certainly not sub 1.0C).

    It may be a long time before we see its like again - unless, of course, we are entering a period of sustained cooling. Personally I doubt it, but then I would have doubted that we could come in this far below 3.0C again.

    post-364-12644658767028_thumb.gif

  3. post-364-12636465360028_thumb.png

    Latest projection from Stratosdale herewith.

    Sub 2C now looks unlikely, but not yet out of the question. Coldest month of the christmas pudding would require a major shift in projection, but coldest January is probably still better than evens, probably around 70-30 I'd say. Certainly sub 3C though.

  4. Anyone know what the record low temp is for Benson? It's currently recording -15c. Seriously cold.gif

    This from the Daily Telegraph last January...

    The temperature at Benson was the lowest in England since the current cold spell began last month, and the second lowest ever recorded in the area. The coldest was -2F (-18.7C) on Jan 14, 1982.

    I'd like to see Benson verified: it's at least 7C colder than anything else in the very near vicinity at present (two stations I can see in Wallingford) and 10C and more colder than the rest of the Chilterns escarpment. That said it is an RAF station, so the readings ought to be robust, and another private station nearby is also showing -15C.

    Looking at the drop off in visibility they've got an inversion now, cold air draining off the hills to the NE. Will be interesting to see how much lower it gets, if it gets much lower at all. Will need the breeze to stay very gentle and around its current vector.

  5. At last a month to challenge the 3C mark. All the elements are in place for once: cold air from a block with decent snow cover over a large part of the country. This latter is vital because it causes significant "drag" on any breakdown, tempering the effect of any milder air mass potentially for several days. Some exceptionally cold days also put negative degrees in the bank - another absent feature in recent years.

    Attached plot projects forward from today, and includes the actuals for three recent markers, the Januaries of 1979, 1997 last sub 3C January, and 2009.

    post-364-12628213750952_thumb.gif

  6. I very much doubt that any absolute cold records will be broken, but there are some spectacularly low temperatures around in central England this evening, and several "coldest since" type records are possible tonight. The evening drop off at Benson, and Woodford, for example, is remarkable by any standards, but in recent times almost certainly unprecedented, and indicative of locations sitting in sinks below uplands, with snow lying, fairly still air, and clear skies; perfect conditions for cold pooling.

    The records set, for example in December 1981, occurred in not dissimilar conditions BUT built up over several days. The record minimum set at Shawbury, for example, and the minima in same period in the Scottish glens (e.g. Braemar) were marked by days where maxima stayed well below, if memory serves me right, -10C, with freezing fog abounding.

    The current set up is likely to be too mobile, and also there is some ephemeral cloud around, both of which will spoil exceptionally low temperatures. Therefore, I'd suggest, some notable lows tonight, but not setting absolute records for the UK, nor coming close to it.

  7. Seem to be located under a long street of showers here in Upper Stratosdale. Near blizzard conditions at times, and like a giant christmas snowstorm through the window. Needed all the traction control the car could muster to get home at 21h, and then only just managed it. Suspect there will be some marked local variation in depths hereabouts in the morning. Wind has scoured the yard clear of snow, but it's piled up to 6" plus on the far side. Suspect level depth at the moment will be around 4-5cm.

    Definitely caught in a remarkably persistent convergence zone here. Drifts outside up to around 40cm, but level snow slightly less than I estimated last night, probably 3-4cm.

    Can't remember an accumulation from showers (without any frontal influence) like this for years.

  8. Seem to be located under a long street of showers here in Upper Stratosdale. Near blizzard conditions at times, and like a giant christmas snowstorm through the window. Needed all the traction control the car could muster to get home at 21h, and then only just managed it. Suspect there will be some marked local variation in depths hereabouts in the morning. Wind has scoured the yard clear of snow, but it's piled up to 6" plus on the far side. Suspect level depth at the moment will be around 4-5cm.

  9. Mix of sleet, and more sleet, here in Stratosdale. Surprising because it was around 5C when this started down in the valley, though a couple of degrees cooler up here. Didn't think this front would have anything wintry on it. Sleet seems to be this season's black up here.

  10. My heart says that we're due a warmer spell, but the form book, and the surface, seem to suggest little change. It's unusual for an average or cooler July to spawn a very warm August. Overall in recent years there's around a 40% chance of August coming in warmer than July, but for years when July landed 16.5C or cooler that drops to below 20%. Not liking the big cold pool in the NA, so...

    A cautious punt from me of 16.3C

  11. If there is any urban heat island effects these will be more pronounced when there is greater solar radiation about to heat up, and reflect off surfaces.

    I'd imagine a tracker methodology, as I imagined it above, would exacerbate heat island effects.

    That might seem logical, but the measured effect is usually greatest overnight in winter under clear skies. UHI isn't only powered by reradiated energy, the energy actually consumed within the urban environment matters too: vehicles, people and particulary buildings and heating. ALL earth surfaces absorb incoming radiant energy to a greater or lesser extent; the man-made component of UHI is much more significant in winter, and then at night.

    The integration approach to deriving an average daily temperature would be mathematically more accurate, however, this has only really been practicable in the past few decades when accurate automated readings became possible. The problem in moving to that method of calculation now would be that the long record [of the CET] would be broken. As your example shows, the daily mean would be skewed - upwards in summer, and downwards in winter - compared with the simple arithmetic mean. It is impossible to recreate this retrospectively - far better to be able to continue to compare apples with apples, even though, strictly speaking, this means that the apparent coldest day in the current record may not have been the coldest by all methods of calculating it.

  12. What? That seems like a very contradictory post; I suggest you read it again.

    That was blatantly not true; we have just had a month at 3.0c. At no point, at least to someone who realised that even 5-10 years of climate data does nowhere near cover anything like the full range of probabilities on our normal curve, did sub 4c look "very unlikely"; perhaps only 1-2 standard deviations were covered on our normal curve, at best, during that particular time period.

    ...Except for the fact that this year it happened at the beginning of December and more especially at the end of December/beginning of January (a case of making a statement based on too little data).

    This was a claim that 05/06 was as cold a winter as it is now possible to get. 08/09 will probably come at somewhere between 3.4 and 3.5, which compared to 4.1 is quite a bit less. Certainly it has proven that 05/06 was NOT as bad as it could get.

    Here was the same emphatic claim made again, with the added intimation that it 05/06 might never be repeated.

    That depends how you define "cold", but December came in well below average and deems that statement at the least dubious, and at the most ridiculous.

    Again a rather vague statement with the word "soon", but if "soon" counts as even 5 years, then such a situation seems some way off, even though I do see it as an inevitability at some point (not "soon", though, in my mind). This year as seen significant, widespread and persistent lowland snow, not "little or none".

    I actually agree with much of what SF says, and he undoubtedly makes some very good and worthwhile points - which I hope he would admit I have always been the first to point out. But in his evident, honourable and true desire to be objective rather than whimsical; rational rather than emotional, I hope he will appreciate my pointing out that he has indeed changed his song, perhaps not without a slight element of disguise, this winter. Some of the above quotes demonstrate this; where once he claimed that 05/06 was as bad as it could get, now 08/09 is as bad as it could get (and no doubt if 09/10 comes in colder, this will be as bad as it can get).

    We are certainly warming, and the chances of of reaching cold months must inherently decrease as a result. I cannot agree more with that. However, I think there is too little evidence to make statements such as "this is as bad as it can get" at this stage :)

    Yeti,

    one needs to cull selectively from quotes with huge caution, one also has to be very careful about interpreting the words of the author - particularly when you have helpfully reproduced them. I would still stand by every one of the snippets you've pulled out there, even if I would take issue with YOUR rather biased REinterpretation of them. I pick my words carefully, you handle them with the carelessness of youth!

    We have landed two 3C winter months in the last 36; you might haggle that odds of 18-1 are very unlikely, but if I asked you for £100, and let you choose in return one envelope from 18, with one of those eighteen containing £1800, would you take the offer? However you look at it, it's unlikely now. Having just had a month at 3C no more proves that sub 3C is possible than does my ability to run a mile at 6' definitely prove that I could run sub 6'. I know it's alluring, but it certainly doesn't prove it.

    I said SUSTAINED WINTRINESS: by wintriness I do not mean cold, I mean cold and snowy, and I think there have been plenty of occasions on which I have made that use of the phrase clear. If you think this winter has shown sustained cold and snowy weather then you probably also believe that Harrogate and Knaresborough stretch in one huge urban sprawl right to the North Sea coast.

    I said "it's about as bad as it can get", not it IS as bad as it can get. Had we landed the sort of February that one or two on here were hollering about earlier in the month this might be a fair challenge. We haven't: we're within about a cumulative degree of 2006; it's the coldest since 1996/7, but nowhere near as cold as the mark set that year; go back another ten years and winters this cold, including many much colder, occurred roughtly every other year. The schoolboy pedant in trying to dissect too carefully the language misses the point, not least given that your statement that I said 2005/6 was as bad as it could get WAS NOT what I said: your carelessness in omitting "about" is vital.

    Finally, you define for me what cold is. The last three months have indeed been relatively cold, for all that Feb is going to land pretty much on it's 30 year rolling mean. However not one of them lands within the coldest 20% relative to it's current mean (this adjusts for the current climatic average), and not one lands in the coldest third of all time for its month. 3C may feel cold, but it is nothing like as cold as the UK used to get. Again, if you care to read all the posts on this point down the years this is not reinvention on my part.

    The extent to which I have moderated my position this winter is limited by the extent to which this month looked like breaking the mould. In a strange way, the outturn of the winter, and this month in particular, simply serves to make my own support for my hypothesis even stronger. People have got far too attached to 3C: this is not me moving my position, it is me seeking to ensure that people do not, in some zealot's desire to see the precise line broken, miss the general point: sustained cold and wintry weather like we used to get simply doesn't happen any more. Had February landed at 2.8C, or 2.6C, this would scarcely have been less true I'm afraid. There is such a gap between the line I originally mooted, and the sort of weather that we used to get on occasions, that you could drive the moon and the stars between them. You're simply not old enough to appreciate it, just as when I listen to my mother talking about the drifts (and these in city centres) of 1940, '47 and '63, I too can scarcely imagine the quantum difference.

    There is much of our outlook on life in some of these discussions. I imagine Tamara might be middle aged and still single, still hoping for love and attention that when younger used to come her way much more often than it does now; and perhaps it might, because it once did. I am middle aged and single, and I've had more than my fair share of love and attention; like Tamara I still hope for more love and attention, but I know I'm not as young as I once was, and perhaps the things I once hoped for would no longer covet me as I would them. And you Yeti, you are far too young to know much of love. For all that Dr Zhivago, say, and Tess of the D'Urbervilles, are marvellous books about love that draw the reader into the flesh of the page so that the words course through our veins, and our hearts beat with those of the protagonists, reading about something and knowing it in the flesh are two very different things; just as the even larger teapot and winters of yore.

    ...

    We look comfortably mild for the remainder, indeed minima at their lowest are around 3-5C on the GFS and maxima generally 9-12C. Taking into account that the GFS generally sits on the low side, its not inconcievable that we might reach 4.3-4.5C before adjustment.

    Looking back at this month from thirty years hence, and comparing it with some of the froth at the start of the month, the casual reader would be forgiven for asking what all the fuss was about. For all intents and purposes the month is going to come in around par: quite a turnaround, and one which the unavoidable clumsiness of the period average will mask.

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