December C.E.T

[West is Best]

Either way the CET is going to end up close to average which considering the very mild start is pretty impressive, esp to get down to 4.3C as the low point of the month is a drop of nearly 5C in about 16-18 days!

I think anyone who doesn't call what we've just a cold spell is not really looking at the facts IMO!

Indeed the stats show that the period between the 9-22nd was the joint (tohugh this may change as the offical stats come in the future as Jan 01 also came close) coldest spell since late Dec/early Jan 97...with December 2001.

Very impressive stat there Darren. Yes, as you say that has been a proper cold spell in anyone's book. Remarkable drop in the CET.

[SMU]

Very impressive stat there Darren. Yes, as you say that has been a proper cold spell in anyone's book. Remarkable drop in the CET.

Maybe remarkable, but put the whole month into context with the fact its still nearly FOUR degrees warmer than the Dec 81 Month & that really is worrying when we are saying that this month is significant-

S

Edited December 26, 2007 by Steve Murr

[Snowly does it]

Maybe remarkable, but put the whole month into context with the fact its still nearly FOUR degrees warmer than the Dec 81 Month & that really is worrying when we are saying that this month is significant-

S

True Steve, I think though its significnace is more down to the remarkable comeback from mild oblivion in which we sat Dec 8th from whence we required about 3.7 per day to reach average by months end - a 3 and a half week winter run at nearly a degree and a half under the recent 30 year and degree under the colder 61-90 averages. We will achieve that (fingers crossed) with some mild air to boot late month.

It was never going to be an 81 after the first week.

[West is Best]

Maybe remarkable, but put the whole month into context with the fact its still nearly FOUR degrees warmer than the Dec 81 Month & that really is worrying when we are saying that this month is significant-

S

Steve I'm not sure if you'd been at the bottle when you posted that? :smiliz23: December 81 was the coldest December of the past 100 years. You surely don't expect every current month to be colder than anything else ever seen?

[Nick H]

Either way the CET is going to end up close to average which considering the very mild start is pretty impressive, esp to get down to 4.3C as the low point of the month is a drop of nearly 5C in about 16-18 days!

I think anyone who doesn't call what we've just a cold spell is not really looking at the facts IMO!

Very impressive stat there Darren. Yes, as you say that has been a proper cold spell in anyone's book. Remarkable drop in the CET

You could equally say it is very impressive that despite a cold spell lasting the best part of a fortnight (and yes, it was a cold spell - we are in winter after all!), the CET is as close to average as it is. Furthermore, and I'll admit I haven't compared the stats, this cold spell has been no more remarkable than the cold spell of December 2006 which occured at a similar point in the month.

It was never going to be an 81 after the first week

Actually the first week of Dec 81 was very mild, admittedly not quite as mild as the first week of this month. More fundamentally, it was never going to be an 81 since we just aren't going to see temperatures of -15C in southern England in December anymore. Sorry, but true, at least for now.

Edited December 26, 2007 by Nick H

[Weather-history]

Here's a cold spell that has been largely forgotten overall apart form that sub-zero spell during early February.

22nd January - 5th February 2006: 1.5

Numerically, the December cold spell is not going to be as cold as this.

Edited December 26, 2007 by Mr_Data

[kold weather]

The December 2006 spell lasted about 5 days less and also was also milder then this one, by how much I'll have to look into it but its probably a good 1C over the space of 10 days and a 15 day strech would be milder again...as I said before barring maybe Dec 01 and Jan 01 its the coldest sustained spell for 10 years, granted that may not be saying much but its still the stats.

Mr Data, yeah actually I missed that one, if the Manley figures are to be ued then that cold spell would beat this one by about 0.15-0.2C.

Edited December 26, 2007 by kold weather

[Nick H]

The December 2006 spell lasted about 5 days less and also was also milder then this one, by how much I'll have to look into it but its probably a good 1C over the space of 10 days and a 15 day strech would be milder again...as I said before barring maybe Dec 01 and Jan 01 its the coldest sustained spell for 10 years, granted that may not be saying much but its still the stats.

Mr Data, yeah actually I missed that one, if the Manley figures are to be ued then that cold spell would beat this one by about 0.15-0.2C.

Again I haven't looked at the stats but I imagine end of Feb 05/beginning of Mar 05 would have been just as cold if not colder. Also, what about the first half of Jan 03. Perhaps Mr Data knows?

Edited December 26, 2007 by Nick H

[The PIT]

What's more worrying is that we're talking about a month that's is only going to be between -0.6C and -0.4C below normal as significant. No doubt MR Data could show how far down the list of cool/cold Decembers it is. You could argue that it's significant as it's another month that's so close to the 1970-00 mean and that it shows a halt to warming. It doesn't. Six months in the history of the planet is so insignificant it's not really worth a mention. Warming doesn't say you can't have a series of average months or slightly below months. It's just a natural swing downwards that could be followed by several years or a few months of the same trend or it could simply stop in January.

[Weather-history]

Also 20th February - 6th March 2005: 1.8

That is the Hadley value

Hadley for 10th-24th December 2007: 2.4

Edited December 26, 2007 by Mr_Data

[Nick H]

What's more worrying is that we're talking about a month that's is only going to be between -0.6C and -0.4C below normal as significant. No doubt MR Data could show how far down the list of cool/cold Decembers it is. You could argue that it's significant as it's another month that's so close to the 1970-00 mean and that it shows a halt to warming. It doesn't. Six months in the history of the planet is so insignificant it's not really worth a mention. Warming doesn't say you can't have a series of average months or slightly below months. It's just a natural swing downwards that could be followed by several years or a few months of the same trend or it could simply stop in January.

Quite. Furthermore, if any winter month has tended to be closer to its long term mean than the others, it is December. The greatest mild anomalies in recent years have been Jan and Feb.

[Weather-history]

What's more worrying is that we're talking about a month that's is only going to be between -0.6C and -0.4C below normal as significant. No doubt MR Data could show how far down the list of cool/cold Decembers it is. You could argue that it's significant as it's another month that's so close to the 1970-00 mean and that it shows a halt to warming. It doesn't. Six months in the history of the planet is so insignificant it's not really worth a mention. Warming doesn't say you can't have a series of average months or slightly below months. It's just a natural swing downwards that could be followed by several years or a few months of the same trend or it could simply stop in January.

I think the trouble is when you look at the overall CET for a month, it can easily be overlooked as not being significant. Take November 2005 and you look at that CET of 6.2 Much ado about nothing but when you dissect the month, then the significance is revealed, it was a pretty remarkable month going from exceptionally mild to notably cold. There were only two colder second halves to November since WWII. The overall CET value hides the remarkableness of that month.

December 2007 is going to be more significant than the CET overall will imply, if you see my point

The same point can be applied to sunshine and rainfall totals.

June 2007 was a remarkable month rainfall wise but when you dissect it was even more remarkable when you realise that there was only 6.3mm recorded after the first 12 days. So even a remarkable month can be even more remarkable than the overall figures imply. :smiliz23:

Edited December 26, 2007 by Mr_Data

[Snowly does it]

Actually the first week of Dec 81 was very mild, admittedly not quite as mild as the first week of this month. More fundamentally, it was never going to be an 81 since we just aren't going to see temperatures of -15C in southern England in December anymore. Sorry, but true, at least for now.

Had the current conditions occured over snowcover, we would have gotten close at places like Benson I'd say. You simply can't rule out temperatures like that - the baseline is 0.75 degrees higher, it does not preclude very low minima. 'True', I dismiss. 'Highly Likely' I would accept.

A two week period at over 2 and a half degrees below the long term average is significant - the same way thet a fortnight of 7.6 would have been heralded as the Angel of Climate Change made glorious in even larger teapot zonality.

The period was as cold as the Decembers of 95 and 96. The month will be nearly as cold as that of 2005 which brought in a good (despite Damiens curious enragement at the suggestion) winter.

If the fortnight has been freezing we would have still been in the mid to high 3s, had it been merely an average winter period we would have been somewhere near last year's mild output.

Not sure what more people want - its a significant cold spell at the end of 7 months that are falling below the long term mean as a whole and with one exception the 10 year mean. Its worth talking about, even if it does just turn out to be an interesting short term blip (odds still favour this strongly of course)

Personally, the warming in the UK is overegged - we are coming back from a hyper-active elastic snap and we will settle somewhere cooler than 2000-2006 but well above 71-00

[The PIT]

I think the trouble is when you look at the overall CET for a month, it can easily be overlooked as not being significant. Take November 2005 and you look at that CET of 6.2 Much ado about nothing but when you dissect the month, then the significance is revealed, it was a pretty remarkable month going from exceptionally mild to notably cold. There were only two colder second halves to November since WWII. The overall CET value hides the remarkableness of that month.

December 2007 is going to be more significant than the CET overall will imply, if you see my point

The same point can be applied to sunshine and rainfall totals.

June 2007 was a remarkable month rainfall wise but when you dissect it was even more remarkable when you realise that there was only 6.3mm recorded after the first 12 days. So even a remarkable month can be even more remarkable than the overall figures imply.

Yes but if you discet all the months in the CET series you will find similar data hidden away within the figures. So you're not really comparing apples to oranges. Overall the month isn't going to be significant.

I've got another question though. The inversion is it one of the longest lasting ones recorded or have there been longer???

Don't worry about 2007 I was very interested in it. The most remarkable thing about the period was one very large remarkable fall followed by another not so remarkable large fall which caused the flooding. Plus rainfall in-between which didn't allow the ground to dry out. As Paul Hudson said the "It's remarkable that they were two falls so close together"

[SP1986]

I think the upcoming mild maybe enough to rebound it into </> 0.1C around average.

So 5.0C to 5.2

[Weather-history]

Actually the first week of Dec 81 was very mild, admittedly not quite as mild as the first week of this month.

It wasn't even that mild Nick, overall the CET was only 0.1 above the 1961-90 average by the 7th of December 1981

[Nick H]

It wasn't even that mild Nick, overall the CET was only 0.1 above the 1961-90 average by the 7th of December 1981

Thanks mr D, but what about 1951-80 (or would it be referenced to 1941-70)?

Edited December 26, 2007 by Nick H

[The PIT]

Very mild tonight so far tonight. Okay the rise has been delayed but it should start going up from now on.

[Stu_London]

Very mild tonight so far tonight. Okay the rise has been delayed but it should start going up from now on.

GFS daily temps based on 18z (daily temps means combined max and min)

27th 8.5

28th 10.0

29th 4.5

30th 2.5

31st 3.0

Overall 5.7

Assuming we are 4.5C after 26th, the above only takes us to 4.7C

[reef]

Hadley is now sitting on 4.8C, a 0.1C rise on yesterday.

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

Today and tomorrow could really shunt that upwards, with double figure minima predicted and maxima in the 10-13C range. Thereafter looks cooler and close to average, but shouldnt offer much of a correction. Around the 5.0C looks a good bet for the final number.

[Stu_London]

Hadley is now sitting on 4.8C, a 0.1C rise on yesterday.

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

Today and tomorrow could really shunt that upwards, with double figure minima predicted and maxima in the 10-13C range. Thereafter looks cooler and close to average, but shouldnt offer much of a correction. Around the 5.0C looks a good bet for the final number.

Manley still 4.4C (up to 25th)

It would be wise to remember Hadley usually recalebrate downwards at month end before getting carried away with predictions - still think 4.7 or 4.8 is most likely

[Stratos Ferric]

GFS daily temps based on 18z (daily temps means combined max and min)

27th 8.5

28th 10.0

29th 4.5

30th 2.5

31st 3.0

Overall 5.7

Assuming we are 4.5C after 26th, the above only takes us to 4.7C

You may be a tad low at the month end Stu, but particularly re the 29th when the max may be set late on the 28th. Could still widely be 10-11C in the south at the start of the period, so the daily mean could easily be as high as 6.5 or 7, and the south doesn't really ever get very cold over the w/e. I'd reckon around 25-27 cumulative degrees still to come this month, and a finishing point, assuming we're at 4.65 to c.o.b. today, of around 4.9 on that basis.

[The PIT]

4.7C rounded up on Climate UK and another rise today before cooler weather will slow the rise. Should end up being fairly close to average now but just below.

[Stu_London]

15th - 6.1

17th - 5.5

19th - 5.1

21st - 4.7

23rd - 4.5

24th - 4.4 (lowest)

25th 4.6

27th 4.8

29th 5.0

31st 5.0

My mid month projection has, I believe been with 0.1C thoroughout - that run may end as I expect 4.8C to be the final figure now

I would like to take credit, however I concede that the accuracy has more to do with the GFS excellent handling of surface temperatures throughout the cold spell and the timing of the breakdown.

[Stu_London]

4.7C rounded up on Climate UK and another rise today before cooler weather will slow the rise. Should end up being fairly close to average now but just below.

Manley is not 4.7 rounded up on Climate UK - it is 4.6 rounded down

If you are going to quote from other sources, it is important that you get the detail right