September CET

[kippure]

And Kippure notched his down from the outragous 16*c he posted first to a more reasonable 15.5*c half way through!!!

I think i posted 16C on the 24 of auguest, but on the 14th of september the cet had risen to 17.2C. Tiny bill was 11c and i was 16C, i ended up 15.1C and tiny bill ended up 6.3C.

[Dawlish]

And Kippure notched his down from the outragous 16*c he posted first to a more reasonable 15.5*c half way through!!!

Oh right! Missed that. Somebody must have won and if somebody won, they must get a prize! It was like that at all the kiddies parties I went to......mind you it did get difficult fitting into in the chairs when I got past 30.

Paul

Edited October 2, 2006 by Dawlish

[Terminal Moraine]

The 1730's is no comparrioson really to recent years IMO and years that follow. This 'warm period' is longer and hotter and is only comparable to the Mediaval Warm period and Roman period.Hving said that Autumn 2005 is simialr to 1730 and '31, but then 1741 went 14.7, 11.0, 7.8 and that was after the coldest year on record not before it.

I think you missed the point I was making, Mike. Undoubtedly the last 19 years have produced more years with a mean temp' exceeding 10c than the period 1720-1739 but if we look at the anomaly relative to the period preceeding and following, the period 1720-1739 is more anomalous than the last 16 years.

The mean annual CET for the period 1690-1719 was 8.78c, for 1720-1739 it was 9.58c and for 1740-1769 it was 8.68c. This gives a difference of 0.80c over the preceeding 30 years and 0.90c over the following 30 years.

The mean annual CET for 1960-1989 is 9.44c and for 1990-2005 it's 10.20c, a difference of 0.76c.

O.K, we still have 3 more years to go to make this a 19 year period and therefore exactly comparable to the period 1720-1739, we are also talking about only tenths or hundredths of a degree C which isn't a huge amount

but my point is that the 1720s and 1730s were equally, if not more, anomalous to the contemporary period as is the period in which we are now living.

It remains to be seen what the next 30 years will bring and how the current period will fit into the longer pattern.

If the current warmth continues unabated, or increases, in the next 10-15 years it will unprecedented both in absolute terms and anomalously but the 1720s and 1730s demonstrate that natural climatic variation can result in temperature anomalies as great as those we are currently experiencing; let's not lose sight of the fact that sudden reversals are also possible and not yet to be written off.

T.M

[Glacier Point]

Verification of September's CET prediction - coments in green bold:

Statistically, a month for neutral Arctic Oscillation (AO) conditions to likely prevail with 59% of all Septembers since 1950 falling within the neutral bandings (+0.5 > -0.5), and a slight preference for -ve conditions if not with 19% of these recorded.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

- very much a neutral or even +ve AO month - perhaps related to state of QBO and tropical depressions forcing the AO +ve

The composite anomalies for the September AO look like this:

http://www.cpc.ncep.noaa.gov/research_pape...ASO.z500.ao.gif

-not a good match on the 'standard' AO+ve pattern from the observed 500 hPa geopot. anomalies - I suspect sea temperatures within the context of a neutral / +ve AO were key here:

The North Atlantic Oscillation (NAO) is strongly lead by the AO during this month:

http://www.cdc.noaa.gov/Correlation/Table/corr.table.sep

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

-no evidence of a +ve AO leading the NAO there, perhaps also indicative of AO conditions fighting with the opposite NAO sign ?

whilst the oceanic sea surface temperature anomaly (SSTA) signal for the NAO remains negative with strong anomalies in the northern sector and less warm anomalies over the sub-tropical region.

This leaves the door open for a SSTA-driven month which is now being influenced on a broader hemispheric scale by a weak El Nino..

Conditions in the Atlantic remain much the same as they did in the early Summer with a notable warm SSTA to the west and cooler SSTA to the east and south favouring a western ridge-eastern trough scenario in the jet with low pressure to our SW.

-very pleased with this verification which was close to observed

There are not many Septembers to allow a robust composite anomaly analysis, but for what it's worth, a weak El Nino (and for that matter neutral conditions) favour a strongly meridional pattern with the jetstream and Azores high pushed SW into Atlantic, but with a ridge solution over Scandinavia. This leaves the UK in a warm SW'ly airstream.

Predicted temp. anomaly pattern:

Observed temp. anomaly pattern:

-similar pattern but very much elevated to 3 C above.

This solution fits quite well the likely SSTA drivers so I'll give the greatest probability to a neutral or even weakly -ve AO and NAO to prevail within the context of ridge-trough in the jestream over the Atlantic leading to an increasing ridge developing mid to late September over Scandinavia and shallow trough to our SW which will no doubt draw some warmth from ex-tropical depressions. This will be tempered somewhat by the continued low latitude ITCZ and -ve phases of the AO.

The sea temperatures to our SW remain much above normal, so given this and the prospect of some late September warmth, I'll go for a CET return of 1.2 above.

14.9 C for me thanks. GP

Obviously 1.9 C below the observed record temp outturn but encouragingly the overall synoptic prediction was quite accurate - perhaps too much emphasis on a -ve AO when +ve was more the call.

Score 1 pt or deduct 1.9 under the new league table scoring system

Edited October 4, 2006 by Glacier Point

[West is Best]

Is Green the new Italic?

[Stratos Ferric]

I think you missed the point I was making, Mike. Undoubtedly the last 19 years have produced more years with a mean temp' exceeding 10c than the period 1720-1739 but if we look at the anomaly relative to the period preceeding and following, the period 1720-1739 is more anomalous than the last 16 years.

The mean annual CET for the period 1690-1719 was 8.78c, for 1720-1739 it was 9.58c and for 1740-1769 it was 8.68c. This gives a difference of 0.80c over the preceeding 30 years and 0.90c over the following 30 years.

The mean annual CET for 1960-1989 is 9.44c and for 1990-2005 it's 10.20c, a difference of 0.76c.

O.K, we still have 3 more years to go to make this a 19 year period and therefore exactly comparable to the period 1720-1739, we are also talking about only tenths or hundredths of a degree C which isn't a huge amount

but my point is that the 1720s and 1730s were equally, if not more, anomalous to the contemporary period as is the period in which we are now living.

It remains to be seen what the next 30 years will bring and how the current period will fit into the longer pattern.

If the current warmth continues unabated, or increases, in the next 10-15 years it will unprecedented both in absolute terms and anomalously but the 1720s and 1730s demonstrate that natural climatic variation can result in temperature anomalies as great as those we are currently experiencing; let's not lose sight of the fact that sudden reversals are also possible and not yet to be written off.

T.M

Of course, the other vital variable that we're missing when making comparisons is a global perspective. One of the reasons why I tend to argue strongly for warming, whether I like it or not, is that the current warmth, whilst temporally anomalous, is a pretty global phenomenon. I wonder whether the same was true in the 1720s.

[acbrixton]

Of course, the other vital variable that we're missing when making comparisons is a global perspective. One of the reasons why I tend to argue strongly for warming, whether I like it or not, is that the current warmth, whilst temporally anomalous, is a pretty global phenomenon. I wonder whether the same was true in the 1720s.

Two useful points here:

1. We should not attempt to draw broad conclusions from our own small land; and

2. What was the global position in the 1720s? Here I suspect we shall never know the answer as Romer and then Fahrenheit had only just developed reliable scales and, in the case of Fahrenheit, a reliable mercuy thermometer in the early 18c. As it was not until the mid 19c that anything approaching a reliable coverage of recording stations came into being our sources would have to be secondary. I don't suppose that continental Europe had the equivalent of the saintly Gordon Manley?

Regards

ACB

[Terminal Moraine]

Fully agree with the two posts above. The only reason I was concentrating on the parochially small piece of the world that is Britain

( England ?) is that I happen to live in it and therefore whatever the weather is affects me directly. Also I don't have any data for the rest of the world in the early 1700s.

I certainly don't dispute that the earth as a whole is warming, irrespective of what happens here, but I stand by the statement that, even on a warming earth, there will local negative anomalies which could just as easily affect our particular neck of the woods as anywhere else.

I might have a Google to see if any research has been done on the likely global temperature in the early 1700s.

T.M

[Thundersquall]

Was the September Manley and /or Hadley CET a UK record?

Edited October 4, 2006 by Thundersquall

[Bottesford]

Was the September Manley and /or Hadley CET a UK record?

Yes warmest September on record for both datasets I think.

[Thundersquall]

This year, up to and including September, we have: 104.52 / 9 = 11.61c.

The average should be: 94.6 / 9 = 10.51c.

Therefore, the current annual average temperature up to and including September, is,

according to the Netweather UK Temperature Tracker, 1.1c above average.

How much above average must the annual average temperature be to be a record-breaker?

Edited October 4, 2006 by Thundersquall

[Guest Mike W]

Manley CET for september was 16.6 which equals the 1729 record whereas the Hadley one is 16.8,which beats it. Both of course are subject to change.