Jonnie G

18.4 C is a bit warmer than 'quite warm' Roger - it ranks 8th in the July CET series! It's a big ask from the set up we seem to be in at the moment.

I will go for 15.8C pelase.

I'll go for 15.6C please.

slightly below average, 7.6C please.

Current five year rolling averages are:- February 4.9C December 5.2C January 5.8C The January figure is the highest in the CET series, having previously peaked at 5.4C in 1737. I was surprised to find that the five year rolling mean for February fell to 1.9C in 1987, the lowest five year period since before 1700 when the temperature readings are to the nearest 0.5C, and presumably not so reliable. The five year rolling mean to January 1943 came in at 1.8C, the coldest January period of the 20th century, however Januarys have been through much colder spells than this, being as low as 0.6C for the 5 years to 1815, and 0.8C upto 1780. It seems that January really is the month that's put in the most warming historically, and is presumably therefore the month with the most potential for cooling off again at some point.

March can be a wintry month, and in this year without a winter I very much hope that it will be, but realistically I think I will go for a mild 7.2C please.

Is a sustained arctic blast possible still? Or to put it another way is sustained northern blocking especially over Greenland possible still? I think it is, as I subscribe to the point of view that we have experienced a synoptic flip similar to those of the past which have abruptly flipped back, and this synoptic flip has coincided with global warming which has amplified the effect. I was astonished to discover that the 5 year average rolling January CET has only just this January surpassed it's all time high......... recorded in January 1737! Three years later and the synoptics had flipped, with a January CET of -3C, and one of the harshest winters ever recorded. So you never know, but I think there may be something in the suggestion that cfc destruction of the Ozone layer has resulted in excess stratospheric cooling and associated strong formation of a polar vortex over Greenland.

Yes SF a fascinating piece of research which I wasn't aware of before picking it up on this forum.......I had realised that the Gulf stream in it's own right is a relatively minor player in warming north-west Europe as there would still be a huge body of water to our west to carry heat from the summer even without a warming current. I had not however realised the role played by the Rocky mountains in causing a large scale disturbance of the global flow, giving for the UK a mean South-Westerly instead of a mean Westerly. This synoptic difference is huge, and I fully accept that the Gulf Stream is responsible for only around 10% of our positive global temperature anomaly in winter, contrary to popular belief.

I guess people at Dalwhinnie or Tomintoul in the highlands would say this January's been okay with snow cover for around half the month. Do we have any members from these places?

I'd have thought it will be at least 4C difference between the met office's warmest and coldest climatic regions of the UK this January. The average difference between the Warmest and Coldest climatic region is 2.6C for January.

Yes, let's remember what a totally random and irrelevant statistic that one is!

If you read my response 259 to SM you will see that I do believe in GW.

The point abouth the examples from mid feb - mid march '05 and '06 that I quoted to SM is that they were each a month long, but I agree that getting a sub 2 month is now difficult. As an aside, I noticed that of the sub 2 Januarys quoted by LP, 3 were sub 2, 5 were sub 1 and 3 were sub zero. It seems that once your sub 2, you're more than likely to be sub 1 also.

Note the even bigger gap for January CET between 1900 and 1917....infact it's between 1897 (1.6C) and 1917 (1.6C). I didn't realise that your comment that a December CET of 2C was as likely as 10C was not meant to be taken literally.

I couldn't agree with those odds - I feel that in the current climate sub 2 wouldn't be that hard to achieve in February if we could get mainly polar air and an anticyclonic spell, such as mid feb - mid march of both 2005 and 2006 only a fortnight earlier. Also a cold December with an inversion might manage sub 2, but for now I'm afraid the mid winter period of January has become a write off. On the other hand, a 20 month has never happened, never mind 21 so as I say, I couldn't agree with those odds.

I agree that cold January has become a much longer shot, and the world is warming, but I don't think global warming is the reason for this change. Somebody suggested (was it Len?) that we are seeing the results of stratospheric cooling caused by ozone depletion by cfcs, resulting in a strong polar vortex setting up over Greenland each winter. This is the thing that's changed... the persistence of that vortex. Scandinavia has had some ridiculously mild seasons of late - probably +10C in parts so far this winter, and this is of course an issue of synoptics rather than warming. The reasons behind the synoptics are a different matter, but I'd favour the ozone depletion idea over warming at the surface, or perhaps a cyclical process of some kind. No offence but that statement is absolutely ridiculous.

Yes, and IF we get a classic, this month will be remembered as a good winter month with perhaps a below average CET. Perhaps with the global wind anomalies falling, and this low GLAAM business or whatever it is, we're more likely to see either persistent southerlies or persistent northerlies. Let's hope it's the latter, and should such a pattern change come to pass around the 20th then it will have been called remarkably well by our resident experts! Nice piece of hopecasting there Roger. The CET will NOT be in the high sixes by the 20th. It would require a pretty exceptional mild spell to get there by the 31st, obviously I'm hoping it doesn't!

Well for me, my real intrest in wintry weather stems from the winter of 78-79, when I turned 11 yrs old. As far as snow goes, then there is before 15th of february 1979 and after that date, because the blizzard on that day in the north-east midlands was extraordinary - there had been a lot of snow up to that point in the winter, with the new years blizzard giving quite a thick cover and many more falls of a few inches in January and February, with sledging and snow fun routine, but looking out of my bedroom window on the morning of the 15th February I saw a completely modified landscape, with elaborate snow formations on the same scale as the fences and window levels.....there was even a small snow drift in the living room! As far as cold goes, then I too remember the degree of cold could be judged by how far up the inside of the window the ice had got overnight, and I remember one day in January 1982 the whole inside was covered in the frosted pattern, and I checked the max-min thermometer in the garden and found it had fallen to -17C. I also recorded -17C during the 1987 spell, although we had double glazing by then, but there's no dought that some of the spells in 78-87 period were remarkable. Another memorable thing from cold spells of the past is the way the milk would freeze on the doorstep pushing the bottle tops off!

That's an interesting bit of number crunching there SF.....Very noticeable from the block bars is the lack of 5 or more day sub zero average periods in the last decade, and that they were so commonplace from 78-87, although I guess we knew that really. I will say that, along with various other members, my opinion is that we're most likely looking at a process that is somewhat cyclical, and we'll see the frequency of the block bar events go up quite a lot in the not too distant future. Not that I'm suggesting the world isn't warming though.

Perhaps the 30 day rolling average together with the seasonal average would be the best stats to look at. Afterall, monthly bondaries are random.

True, although I think mr Data might confirm that there were month long periods below 3 from mid feb-mid march of both 2005 and 2006.

I don't think there is an official station at an inhabited place in Britain with a January average below 0. Braemar came pretty close from 1961-90 with February at 0.6C. http://www.metoffice.gov.uk/climate/uk/ave...es/braemar.html

I seem to be contradicting you rather a lot today pp, but in actual fact flash sits at 1500 feet asl....I went on bike ride there as a teenager. There are some very large high level lodges in the highlands, there's one near dalwhinnie at about 500M asl, so that might be the coldest inhabited place in the uk.

I would like to revise my prediction to 2.1 please.

The cycle of warmth to be broken with a CET of 1.1C please.