December CET

[TEITS]

it's been the coldest I've ever experienced in this country and although I'm only 20, that's quite something considering the exceptional heat the country has also experienced in my life time!

I've experienced far colder and heavier snowfalls than Dec 2010 with Dec 1981 being far more severe for my location compared to this one. However what makes this month so incredible is the length of the cold spell with only a few less cold days mid month. However what Mr D has just posted about Nov-Dec is just incredible.

I remember Stratos Ferric was one member very keen on reminding us how these cold spells were a thing of the past but we argued if you get the right synoptics then we can still record see a sub zero CET winter month.

[reef]

I've experienced far colder and heavier snowfalls than Dec 2010 with Dec 1981 being far more severe for my location compared to this one. However what makes this month so incredible is the length of the cold spell with only a few less cold days mid month. However what Mr D has just posted about Nov-Dec is just incredible.

I remember Stratos Ferric was one member very keen on reminding us how these cold spells were a thing of the past but we argued if you get the right synoptics then we can still record see a sub zero CET winter month.

I see a lot of mentioning and wrong-quoting of SF on these threads and Im going to have to defend him here. He most certainly did NOT say that such months were impossible, but rather as the baseline temperature increases they become more difficult to achieve. At the point in time this was being discussed it was a very valid statement and it still is until this current downturn in temperatures is proven not to be a mere blip.

This misdirected sense of 'I told you so' from cold lovers is ridiculous.

Back on topic and Hadley is -0.9C to the 25th. Yesterday came in at -4.3C. Another chilly min today too at -9.0C, so a figure of -1.0C is likely tomorrow.

[Beazle]

..... Hadley is -0.9C to the 25th. Yesterday came in at -4.3C. Another chilly min today too at -9.0C, so a figure of -1.0C is likely tomorrow.

I see that Phillip Eden has -1.3 . Can you explain to me why PE and Hadley seem to disagree ? I would have thought, perhaps simplistically, that a CET is a CET ....Obviously not !

Its going to be the coldest November-December CET combination since at least 1890.

If December 2010 turns out exactly zero then November-December 2010 will have a CET of 2.6C

November-December

1890: 2.45

1879: 2.4

1878: 1.6

1874: 2.7

1870: 2.65

1807: 2.4

1796: 2.15

1782: 2.55

1683: 2.5

1676: 1.5

Sensational!

Yep ! And unless something really sensationally warm happens on Wednesday and Thursday, we should have something colder than zero. I see that this morning's update (3.46am) seems to reduce the previously warmer figures for Wednesday-Thursday,....so we shall see.

[Terminal Moraine]

I see that Phillip Eden has -1.3 . Can you explain to me why PE and Hadley seem to disagree ? I would have thought, perhaps simplistically, that a CET is a CET ....Obviously not !

The CET figure is entirely dependent on the stations selected to supply the data. As far as I can remember Philip Eden uses station which most closely represent those originally used by Manley. I would have to look up the stations used by Hadley ( I bet someone on here knows them by heart) but I seem to remember there are fewer of them than Philip uses, and some, at least, are different.

Edit; I just looked it up and Hadley uses Pershore in Worcestershire, Rothamstead in Herts and Stonyhurst in Lancashire.

All I could find for Philip Eden is that he uses a selection of stations between Oxfordshire and the Lancashire Plain which most closely represent those used by Manley.

Edited December 26, 2010 by Terminal Moraine

[Beazle]

The CET figure is entirely dependent on the stations selected to supply the data. As far as I can remember Philip Eden uses station which most closely represent those originally used by Manley. I would have to look up the stations used by Hadley ( I bet someone on here knows them by heart) but I seem to remember there are fewer of them than Philip uses, and some, at least, are different.

Edit; I just looked it up and Hadley uses Pershore in Worcestershire, Rothamstead in Herts and Stonyhurst in Lancashire.

All I could find for Philip Eden is that he uses a selection of stations between Oxfordshire and the Lancashire Plain which most closely represent those used by Manley.

Thanks for that. I suppose it doesn't really matter 99% of the time but in the present exciting circumstances, we don't want a squabble over whether or not this was THE coldest December ever. I guess that is why this site uses Hadley even if it is not quite as accurate (in Manley terms) as one would want. At least we have a consistent means of comparison.

[Stu_London]

I see a lot of mentioning and wrong-quoting of SF on these threads and Im going to have to defend him here. He most certainly did NOT say that such months were impossible, but rather as the baseline temperature increases they become more difficult to achieve. At the point in time this was being discussed it was a very valid statement and it still is until this current downturn in temperatures is proven not to be a mere blip.

Assuming one still believes we have higher baseline temps (which would make December 2010 even more extraordinary), then the above is correct, although he did say that he doubted there would be a sub 10C year in his lifetime, which is looking like a rather silly statement now.

I think the problem is, or was, is that if one makes statements in an overly authorative tone and are dismissive of anyone with differing views who wants to engage in a debate, then one does rather leave themselves open to attack in the event that ones assertions prove not to be correct.

1796 - 21st to 27th -3.6C (christmas day managed -10.8C that year)

1798 - 24th to 30th -4.5C

1859 - 13th to 19th -4.9C

1870 - 21st to 27th -4.4C

1981 - 8th to 14th - 3.5C

The period 19th to 25th December was be my reckoning, the 4th coldest December week in history at -4.04C. This is a provisional figure, so might be worth double checking when final figures are available. beating 1870 and 1798 might be possible with downward adjustments, however i suspect 1859 will remain the daddy.

[Duane S.]

Assuming one still believes we have higher baseline temps (which would make December 2010 even more extraordinary), then the above is correct, although he did say that he doubted there would be a sub 10C year in his lifetime, which is looking like a rather silly statement now.

I think the problem is, or was, is that if one makes statements in an overly authorative tone and are dismissive of anyone with differing views who wants to engage in a debate, then one does rather leave themselves open to attack in the event that ones assertions prove not to be correct.

Indeed, people can defend him but he made heaps of matter of fact statements that were far from ambiguous and unlike another certain member who has least still comes on and posts despite the barrage of "ha ha, told you so's", he has not. I'm sure it's just a coincidence though...

The fact we are sat here debating whether this December will be the xx coldest in history is the truly remarkable fact here though and it is strange how you sort of get used to it being 'yet another' ice day !

[Snowyowl9]

The brook here has totally frozen over I can`t remember the last time that happened.

This is looking like a very close CET to feb 1986 but where exactly.

-0.9c on hadley

-1.3c on manley,CET west has been colder CET east will be colder to the west days ahead.

How far will the mild/less cold air reach east not far enough for a cold record breaker.

I`l be very happy with -0.9c

[AderynCoch]

Is the lowest average CET minimum for December nailed? The figure is -3.4C to the 26th, compared with the current record of -2.7C (shared jointly by 1890 and 1981).

Average CET maximum so far is 2.2C to the 25th, but the record is out of reach (1.2C in 1890). Second place is looking likely at the moment (currently held by 1878 with 2.7C).

As for the record mean itself? Going right down to the wire, though I agree that we'll probably end up relying on post-month adjustments.

[Stu_London]

could be a suprisingly low minima tonight.

Although temps will hovering around freezing by 6am tomorrow, temps now in parts of the CET zone are up to 7C below freezing. Can't remember if the minimum is recorded from 6pm or 9pm, either way it will be much colder than by tomorrow morning.

With tomorrows max unlikely to get above a raw 1C or 2C, the 27th should see no rise at all and may even be a marginal fall.

[Gavin P]

Yes Stu and the heavy snow being foecast by NAE (if it comes off) on Tuesday morning should help keep temps pegged back through the zone on Tuesday afternoon. That really just leaves Wednesday to Friday, which are going to do a bit of damage, unless something comes to our rescue, maybe like widespread, lingering fog, which of course is not out of the question given we'll have warmer, damper air overlaying frozen, snow covered ground.

[Snowyowl9]

Gavin P fog will be out of the question once these fronts come in,hill fog maybe theres going to be a good deal of cloud this coming week 7c maxes but getting colder later but HP only over scotland thaw all next week slow at least.

Winds back from the east but it`s how I remember an average easterly for the time of year HP over Scotland.

I still think -0.9c final figure.

Edited December 26, 2010 by Snowyowl9

[Weather-history]

Manley CET: -1.4C by the 26th

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

It was a long time ago that we had a value that low so far into the month.

Its going to be the coldest CET month since February 1986

[Beazle]

Manley CET: -1.4C by the 26th

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

It was a long time ago that we had a value that low so far into the month.

Its going to be the coldest CET month since February 1986

Today to Thursday are the danger days...........................

[Weather-history]

I see a lot of mentioning and wrong-quoting of SF on these threads and Im going to have to defend him here. He most certainly did NOT say that such months were impossible, but rather as the baseline temperature increases they become more difficult to achieve. .

Stratos ferric on the 26th January 2010

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

[Beazle]

Stratos ferric on the 26th January 2010

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

You don't have to be a QC (although it just so happens...) but the highest "SF" said was..."may"... and.. "..doubt"..

In other words he was sensibly not being dogmatic about his thoughts.

Edited December 27, 2010 by Beazle

[Beazle]

Manley CET to the 26th= minus 1.4 - Hadley =minus 1C

[Duncan McAlister]

I see a lot of mentioning and wrong-quoting of SF on these threads and Im going to have to defend him here. He most certainly did NOT say that such months were impossible, but rather as the baseline temperature increases they become more difficult to achieve.

I will go even further back than Mr Data

SF on 28 Feb 2007 on the thread 'Are we still capable of getting a <1c CET month?'

No, not even a remote possibility...

This quote really stuck in the memory and a quick search through the archives confirmed it.

[paul tall]

LOL, it is a bit unfair to laugh at a member that is no longer here to defend themselves though?

Anybody know what happened to SF? Spat his dummy out and ran away when we got cold? (I remember him talking about going out to dinner with important climate change industry managers) Or just found better stuff to do than hang about on weather forums?

Where is he?

[BornFromTheVoid]

Todays minimum is -6.3C, maxes are around 3C, so we'll probably remain at -1.0C for tomorrows update.

Going by the 06z GFS we'll be at...

-0.9C to the 28th (+3.2C)

-0.6C to the 29th (+5.5C)

-0.5C to the 30th (+5.2C)

-0.3C to the 31st (+3.9C)

Somewhere between -0.4C and -0.7C after corrections.

[Weather-history]

If you group together all the official and provisional CET daily means for 2010 that were sub-zero, they total 31 with a CET mean of -2.6C thus far

Thats 1/12th of 2010 having recorded official and provisional sub-zero CET means

26th November-26th December CET: -1.1C

Edited December 27, 2010 by Mr_Data

[Optimus Prime]

LOL, it is a bit unfair to laugh at a member that is no longer here to defend themselves though?

Where is he?

His choice if he chooses not to come here. It does make me laugh somewhat.

[paul tall]

Yes, it is a little bit funny to be fair, especially the "not a chance" comment to the <1º question.

That said, two years ago, how many of us would really have believed such a month (let alone a sub zero month) would happen again?

[eddie]

One of the ways I like to rank months is by their anomaly from the rolling 30y mean.

First I calculate each month's anomaly from the previous 30 year mean (e.g for 2007 I would subtract it's value from the 1977-2006 mean).

I then find the standard deviation of the entire anomaly data set and then divide each anomaly by said standard deviation.

You can then rank each month by how exceptional it was compared the climatic norms of it time.

So for example, ranked in this way, December 1981(0.3C, -2.7 standard deviations from 30y mean) was colder relative to it's previous 30 years than was 1874 (-0.2C, -2.6 sd. from 30y mean).

Obviously this month will be by far the coldest when ranked this way and is likely to be the first December that hits -3 standard deviations. This is something you would only expect to happen less than once in every 200 years.

[drabux]

Yes, it is a little bit funny to be fair, especially the "not a chance" comment to the <1º question.

That said, two years ago, how many of us would really have believed such a month (let alone a sub zero month) would happen again?

Approx 74.55% did back then.

http://forum.netweat...3B1c-cet-month/

One of the ways I like to rank months is by their anomaly from the rolling 30y mean.

First I calculate each month's anomaly from the previous 30 year mean (e.g for 2007 I would subtract it's value from the 1977-2006 mean).

I then find the standard deviation of the entire anomaly data set and then divide each anomaly by said standard deviation.

You can then rank each month by how exceptional it was compared the climatic norms of it time.

So for example, ranked in this way, December 1981(0.3C, -2.7 standard deviations from 30y mean) was colder relative to it's previous 30 years than was 1874 (-0.2C, -2.6 sd. from 30y mean).

Obviously this month will be by far the coldest when ranked this way and is likely to be the first December that hits -3 standard deviations. This is something you would only expect to happen less than once in every 200 years.

I agree with this approach. 3 sd indicates a 1 in 200 yr event, as you say.

Edited December 27, 2010 by drabux