Jump to content
Holidays
Local
Radar
Pollen
Sign in to follow this  
SP1986

Annual CET

Recommended Posts

Were coming to that time of year again.. the end that is.

It's going to be interesting to see what the CET will come out as, and based on the Hadley obs, it should finish around 10.6 to 10.7C, narrowly avoiding a record in the process.

Share this post


Link to post
Share on other sites

Quite funny that 2011 is one of the warmest CET years on record.. but except for April and late September/early October it has not felt warm.. maybe it's because all the warmth occurred in the wrong months!

Share this post


Link to post
Share on other sites

Just yesterday Météo- France made the official announcement that 2011 is the warmest year in France Nationaly that is.It made the headlines here yesterday on newspapers and on the tv news.

January +0,3 c

February +1,2c

March +1,2c

April + 4c

May +2,4c

June + 1c

July -1,3c

August +0,5c

September + 2,1c

October +1,4c

November +3c

December aproximately ( Météo-France sources) +2c ( to 2.10 or 2.20c )

It is to note that the warmest 12 month period ever was from June 2006 to May 2007 with the anomaly at a crazy 2.3c .

But then it is not on a calendar time scale and it did not made it on the headlines.

2011 then behind 2003 and 1994

13.6c is the 2011 mean average against a 12.15c average but Météo-France still uses the 1971-2000 period.

Aaron with 5 months above the 2c anomaly but yes in" the wrong months ", it is still an extraordinary year for temperature!

But then never beats the June 2006 to May 2007 period!!!which was worrying with its anomaly!!!!!!

Edited by jean91

Share this post


Link to post
Share on other sites

Jean, what is Paris normal mean? I assume you mean France as a whole has a normal mean of 12.1C?

Share this post


Link to post
Share on other sites

Quite funny that 2011 is one of the warmest CET years on record.. but except for April and late September/early October it has not felt warm.. maybe it's because all the warmth occurred in the wrong months!

Yep, all three months in the summer quarter coming in below even the long-term average (1659-2010). Apart from the cusp of September/October and a few days in April, the warmth has been far from useful from my point of view.

Share this post


Link to post
Share on other sites

Yep, all three months in the summer quarter coming in below even the long-term average (1659-2010). Apart from the cusp of September/October and a few days in April, the warmth has been far from useful from my point of view.

The year 2011 has been the second warmest year on record, with the warmth concentrated in the February to May period then again in the September to December period, with natural variablity producing a cooler three months in between, which just so happened to co-incide with the summer months. It is a random chance during any year and even during very warm years as to what time of the year the core of the warmth occurs in. It was just down to a random chance, that the warmth of 2011 didn't occur during the summer months. Whereas in some other very warm years like 1995, 2003 and 2006 the warmth did occur in the summer months.

Likewise, the year 2010 was a cool year, though the cold was largely concentrated in the Jan / Feb, and the late part of Nov and through Dec, and the rest of the year in between was pretty close to average.

Edited by North-Easterly Blast
  • Like 1

Share this post


Link to post
Share on other sites

Jean, what is Paris normal mean? I assume you mean France as a whole has a normal mean of 12.1C?

Yes Sorry all temps above in my post are National ones 12.15c Nationally .

Share this post


Link to post
Share on other sites

Mine's going to be 9.1C, compared to 7.8C last year.

Share this post


Link to post
Share on other sites

Jean, what is Paris normal mean? I assume you mean France as a whole has a normal mean of 12.1C?

Cannot check precisely for Paris now as need to go back to work but we are around a mean of 14c for Paris for 2011 against an average 1971-2000 of 12c.

Will check tonight and after the 31st december for the final figure.

Share this post


Link to post
Share on other sites

It's worth noting that one downside of comparing with the most up-to-date 30-year average is that it masks the warmth of months, seasons and years in a longer-term context. For example, March 2011 came out about average relative to the 1981-2010 reference period, giving the impression that it wasn't a particularly warm month, but for instance it was a full degree above the 1961-90 average. October might have seemed unremarkable considering the warmth of a few recent Octobers but it was barely half a degree short of the all-time record.

The main clincher was the autumn which was almost as warm as the record-smashing one in 2006.

  • Like 1

Share this post


Link to post
Share on other sites

It could be argued that perhaps a 6.7C March is more representitive of an 'average' March nowadays. Against a backdrop of a 0.5-1.0C increase in global temperatures you could say its just as likely to get a March of 6.7C now as it might have been to get a 5.7C one 30 years ago. As you say, in a historical context it masks warmer months now, but then again as recently as 1899 a 5.1C March was seen as average.

Theres also the possibility that the 12.6C in October was actually further from the 'theoretical' warmest CET that could be achieved even though it was mere 0.7C below the record. April is probably a good example, as in 2011 the record set a few years earlier was beaten by some way. It could be argued that the maximum CET possible in that month has steadily risen against the backdrop of global temperatures, but that we just hadnt had the synoptics to achieve anywhere near it for many years.

Certainly some months are probably capable of achieving much higher record CETs now than when they were set.

Share this post


Link to post
Share on other sites

It's an interesting topic, the theoretical extremes of monthly CET.

I suppose if we're talking purely theoretically, without a radical change in the current climate, then the upper and lower limits for any month can be calculated by imagining the warmest/coldest possible synoptics for the month in question and imagining those synoptics persisting for a whole month.

The likelihood of this actually occurring can be calculated by observing what happens, or has happened, in practice over the last 350 years or so. Thus a month like July 2006 could, in theory, be significanly exceeded if one imagines the synoptics of late June/early July 1976 lasting for a whole calendar month.

Similarly a month like February 1947 or January 1814 must be approaching the lower limit of what is possible in reality, although if the synoptics of the coldest part of Jan' 1963 lasted for a whole month even these low values would be eclipsed.

Manley suggested that, without a frozen North Sea, the mean temperature of the coldest month in lowland England could not realistically fall much below -6c, a value which was approached in lowland Lancashire during Jan' 1814.

An April even warmer than that of 2011 is certainly potentially possible but unlikely. Then again I didn't think I'd live to see a warmer one than the previous April record a few years before.

  • Like 1

Share this post


Link to post
Share on other sites

Manley suggested that, without a frozen North Sea, the mean temperature of the coldest month in lowland England could not realistically fall much below -6c, a value which was approached in lowland Lancashire during Jan' 1814.

A -6C month in lowland Lancashire?! I'm finding that very hard to believe, compared with the January 1814 CET value of -2.9C.

Where did you read this?

  • Like 1

Share this post


Link to post
Share on other sites

I think some people are over complicating the potential of CET values because while we can have daily CET means of 10C below or above average, they are never going to be sustained.

In terms of the low and high monthly CET potential we have Januaries which have been about 7C below average and i believe that May had a record value of 15.1C which is over 4C above average which puts the lowest CET we can get in the -2.5 to -3C range and the highest we could get in the 20.5-21.0C range.

  • Like 1

Share this post


Link to post
Share on other sites

Time to update..

So from April 2011 to March 2012 we have a very warm 10.76 which is perhaps the second warmest period on record.

This will drop next month.

Share this post


Link to post
Share on other sites

Time to update..

So from April 2011 to March 2012 we have a very warm 10.76 which is perhaps the second warmest period on record.

This will drop next month.

Its certainly high, but there have been warmer 12 month running periods in recent years:

Mar 1989 - Apr 1990: 10.83C

Nov 1994 - Oct 1995: 11.07C

May 2006 - Apr 2007: 11.63C

It'll fall this month as you say, but this could be clawed back quickly if summer is warm.

Share this post


Link to post
Share on other sites

If just making a year from the monthly extremes the annual CET ranges from a potential minimum of 5.36C (compared to 6.84 in 1740) to a maximum of 13.08C (cf. 10.82, 2006).

Share this post


Link to post
Share on other sites

Time for an update.

From the peak of 10.76C through March, the June 2011-May 2012 CET stands at 10.34 and will certainly fall this month. Will be hard to match July and August but should fall further during the Autumn.

Share this post


Link to post
Share on other sites

Here's a corker for you all, if October comes in below average (looking highly likely) then we will have gone through a 7 month period in which the warmest month versus the 1981-2010 mean was just 0.2C above average and at least 4 of those months will have been 1C or more below average.

Anyhow, with September confirmed at 13.0C we have a rolling CET of 10.26C with a good chance of significant falls in October and November.

  • Like 1

Share this post


Link to post
Share on other sites

Here's a corker for you all, if October comes in below average (looking highly likely) then we will have gone through a 7 month period in which the warmest month versus the 1981-2010 mean was just 0.2C above average and at least 4 of those months will have been 1C or more below average.

Anyhow, with September confirmed at 13.0C we have a rolling CET of 10.26C with a good chance of significant falls in October and November.

The one concern of mine about that though is that it must end sometime, and as you say unlikely to end in October, its sods law that it ends in december!

  • Like 1

Share this post


Link to post
Share on other sites

With the prospect of October being average at best, I would say sub 10 looks the strong form horse now for 2012.

That would be only the 4th time this century

Years with CET greater than 9.99C

1600s 1 from 42 years (2.4%)

1700s 8 (8%)

1800s 9 (9%)

1900s 19 (19%)

2000s 8 (67%)

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×