I'm assuming that means 'be careful'. I'm not challenging GW; I'm reminding you that highly anomalous monthly data does not singularly represent a manifestation of it.

You don't need to remind me of anything although it's always entertaining to be patronised

Only a slight adjustment to the figures today...    My Anomaly was .1c  from 4.9c to 5.0c.  Been out all day as my birthday the 68th in my life....

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You don't need to remind me of anything although it's always entertaining to be patronised

Apologies Sevendust-  reading back it does sound condescending! Not intended. I just wanted to say that I wasn't in any way challenging the global warming idea with the comment I made. Perhaps 'remind' and 'you' were not the words needed.   And I do indeed believe that the frequency of extremes is reflective of something going on. I only meant that we (not you, or anybody in particular) should remain mindful that individual anomalies alone - even fairly persistent ones- are not indicative of the bigger picture.

I see also that your 'caution' was accompanied by a winking emoticon; thought it was a scrunge at first.

Best

Bertie

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Apologies Sevendust-  reading back it does sound condescending! Not intended. I just wanted to say that I wasn't in any way challenging the global warming idea with the comment I made. Perhaps 'remind' and 'you' were not the words needed.   And I do indeed believe that the frequency of extremes is reflective of something going on. I only meant that we (not you, or anybody in particular) should remain mindful that individual anomalies alone - even fairly persistent ones- are not indicative of the bigger picture.

I see also that your 'caution' was accompanied by a winking emoticon; thought it was a scrunge at first.

Best

Bertie

Individual Anomalies make up the bigger picture for CET..... At least  the central Anomalies'   Some people think  CENTRAL should be broadened.  

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Individual Anomalies make up the bigger picture for CET..... At least  the central Anomalies'   Some people think  CENTRAL should be broadened.  

They make up one of the many smaller pictures. They can skew the data, granted; and an extreme anomaly may have a significant effect within a given sample. But the bigger picture I'm referring to is whatever the more representative tendency, pattern or correlation may be. For this December to be representative of the bigger picture, it would have to become nearer the norm. The hub of the current discussion is the non-norm nature of this month. Anomalies are, by definition, not reflective of the overall correlation.

Of course, that's not making any predictions about how the existing norm might change.

Happy birthday by the way.

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I'm so glad you cleared up that little misunderstanding like true gentlemen and kept this thread as lighthearted as it's meant to be! 

Still very mild and mainly grey and damp but we do have the odd glimpse of sun.  Very hard to believe it's almost Christmas with such temps and exciting to see some potential records.

Art, is it your birthday?  (Runs over to Daily Thread)....... 

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Difficult to comprehend the figures at times. Already some talk of next year may be warmer. Just hope we do not get s sudden shock....

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We have our third CET date record in a row now thanks to the incredible temperatures being recorded early this morning which still count towards the maximum for the 18th.

Mean CET for the 18th is currently 12.48C by my calculations but could go higher yet before 0900. Previous record was 11.4C in 1918. Anomaly to 1981-2010 mean is +8.13C.

My CET estimate for the whole of December is now up to 9.80C! I still think we will probably finish just below 10C but it could be touch and go the way things are going.

 

Hadley MAYBE 9.60  LATER..

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I have had a look back through the archives (as far as 1700) to try and find months with a positive CET anomaly of 5C or more. To do this I have used a rolling 30 year mean as this is the only sensible way to do it. No point comparing the CET in 1800 against the 1981-2010 mean as that is somewhat meaningless. I used rolling 30 year means finishing in a year ending with a zero and updating the rolling mean every 10 years.

The result is that while there are plenty of years with a negative CET mean anomaly of more than 5C there are no years with a positive CET anomaly that large.

The biggest positive CET anomaly was 4.9C in January 1796. The CET that January was 7.3C which was 4.9C above the 1761-1790 mean of 2.4C. The 1761-1790 CET mean was especially cold. During that period there were 4 January's with a negative CET and another 4 with a CET between 0C and 1C.

December 2015 could see a positive CET anomaly as high as 5.2C. This would be unprecedented for any month of the year.

 

Hadley MAYBE 9.60  LATER..

My calculations say 9.61C up to the 18th. Should reach 10C exactly by the 22nd.

After that it is anyone's guess at the moment. The 0z output had the CET at 9.8C by the end of the month. The 06z output is much colder after Christmas and pushes the CET down to 9.3C. So a lot of uncertainty at present. Despite that it looks very likely the CET will end up above 9C.

I have had a look back through the archives (as far as 1700) to try and find months with a positive CET anomaly of 5C or more. To do this I have used a rolling 30 year mean as this is the only sensible way to do it. No point comparing the CET in 1800 against the 1981-2010 mean as that is somewhat meaningless. I used rolling 30 year means finishing in a year ending with a zero and updating the rolling mean every 10 years.

The result is that while there are plenty of years with a negative CET mean anomaly of more than 5C there are no years with a positive CET anomaly that large.

The biggest positive CET anomaly was 4.9C in January 1796. The CET that January was 7.3C which was 4.9C above the 1761-1790 mean of 2.4C. The 1761-1790 CET mean was especially cold. During that period there were 4 January's with a negative CET and another 4 with a CET between 0C and 1C.

December 2015 could see a positive CET anomaly as high as 5.2C. This would be unprecedented for any month of the year.

 

It really is amazing. Not, though, the temperature so much but the persistence of the spell and it's location. It looks to me like France hasn't see the record highs/anomalies, nor (for much of the time) has N Scotland, but England has seen what seem like weeks of a run of 'perfect' Swlies - quite amazing. I think I remember previous spells like this sometimes saw the high move a little so that a few days saw the colder nights that the continent is seeing now spread to us - not this time. Otoh, I've seen anomaly maps and this unprecedented warmth is Europe/Russia wide.

What's also interesting is the shape of the euroblob high. In the 70's I seem to remember swlies with a high over France or Iberia, these day we seem to see high pressure with an indistinct centre over much of W Europe, and a rush of winds for the SW over us.

Is it my imagination or is the persistence of weather spells increasing? But, how would we measure such a thing?

edit: one other thing... there are, obviously, twelve 30 day month periods but are there, what, 365 minus about 30 thirty day periods in a year and has one of them had such an anomaly? There a bit of work to do!

 

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The persistence point is one I've been wondering about too. Certainly feels that way - weeks or months of rainfall, likewise with northerly blocking, cold springs, warm autumns etc. But I've no stats to back it up. Time to do some googling.

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Met  Office  Hadley                9.7c.           Anomaly        4.9c.     Provisional to 18th.

Metcheck                              9.66c.          Anomaly         4.67c.

Netweather                          10.27c.         Anomaly         5.18c.

Cheadle Hulme Weather          9.7c.           Anomaly         4.1c.

Clevedon   Weather               11.7c.           Anomaly         4.8c.

Mount   Sorrel                       9.9c.             Anomaly         4.8c.

Peasedown St John               10.4c.            Anomaly          5.1c.

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I have had a look back through the archives (as far as 1700) to try and find months with a positive CET anomaly of 5C or more. To do this I have used a rolling 30 year mean as this is the only sensible way to do it. No point comparing the CET in 1800 against the 1981-2010 mean as that is somewhat meaningless. I used rolling 30 year means finishing in a year ending with a zero and updating the rolling mean every 10 years.

The result is that while there are plenty of years with a negative CET mean anomaly of more than 5C there are no years with a positive CET anomaly that large.

The biggest positive CET anomaly was 4.9C in January 1796. The CET that January was 7.3C which was 4.9C above the 1761-1790 mean of 2.4C. The 1761-1790 CET mean was especially cold. During that period there were 4 January's with a negative CET and another 4 with a CET between 0C and 1C.

December 2015 could see a positive CET anomaly as high as 5.2C. This would be unprecedented for any month of the year.

 

Yes, and doubly amazing since this December will be relative to current averages which I presume are higher than much of the earlier CET record.

Looks like a massive amount of work you've put into working out the 30-year rolling mean GW. Thanks.

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Is it my imagination or is the persistence of weather spells increasing? But, how would we measure such a thing?

 

 

Given the statistically-unlikely occurrence in recent decades of so many 'warmest months' (including an amazing repeat performance for April) you must be right, Dev. To get warmest months, we're talking persistent warmth across a 30 (ish) day calendar period.

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Some reference points:

Coldest May on record: 8.9C in 1902 (we'll beat that). 4 other Mays below 9.5C since 1900
April average: 8.1C (we'll beat that)
April 2015 9.0C (we'll probably beat that)
October: just under a quarter of all Octobers since 1900 were 9.5 or lower

If we hit 9.5C or thereabouts we will be warmer than the Dec average for:

Marseille (8.0C)
Rome (9.5C)
Izmir (9.0C)
Las Vegas (8.7C)

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Truly staggering is all I can say

This December is going to be a true record breaker in spectacular style and imo far more remarkable than 2010 as its expected to be cold at this time of year not t-shirt weather.An expected CET of 10c by 22nd December is insane

My mean is still above 12c at 12.1 c

"The biggest positive CET anomaly was 4.9C in January 1796."

If I'm not mistaken that came immediately after the frigid and record-breaking December of 1795 with its CET of -3.1c a full 10.4c degrees lower.... With only a year separating them!

For the difference with 2010 to be as stark, we'd need a CET of 9.7c... Which looks to be near the mark, so whereas what we have now is truly remarkable, it is not wholly unprecedented...

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My mean now up to 11.2.  Unprecedented, and warm.

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