Yearly CET

[Snowly does it]

Not sure about that. A warm month this month would almost certainly nail an increase, and probably a record year, but something closer to average rules neither out - far from it. By my reckoning we've got 22.8 cumulative degrees in hand on last year. Even an average October (10.7 on the recent 30 years) would leave 12.1 in hand; 6 of the last ten years have exceeded this, and the trend is slightly upwards. If October comes in just a degree above, then with just 11.1 in hand we're in territory where only 2/10 have delivered recently. Short of a repeat of 1996/7 (highly unlikely) then it's long odds on an increase this year if October is >1c above average.

Remember as well, when comparing with last year, that November was cold and December average; that's the coldest lead in in ten winters. In modern winters back-to-back cold is almost unprecedented, and in any case the current fundamentals really don't favour a cold autumn - if anything the reverse is true and as we sit right now a record warm autumn is looking likely. By the end of October we'll probably already be warmer than around 40% of the entire CET series for SON, with a full month still to go. The only ponder is whether this is barmy, or balmy!

Now matter how we try to weave the thread that points to potential cooling, the inherent strength of that thread is tenuous to say the least.

The first part of my post ws relating to a record year, I think the record is where October holds the key (given the very warm october last year and where we are in comparison right now etc)

As for compared to last year, its likely to be marginal either way, probably so much so that it remains on the 4 year 'plateau' we appear to be on.

A cranked up El Nino next year will make for some intersting assessment if we can get it going!

I am not trying to point to potential cooling btw, more a fascination in a possible decrease for another year however minimal with 2 record months in the bag.

My thinking is that were this to continue (on a plateau) with warmer summers then one might start thinking in terms of changes to summer and winter and the influences therein.

Edited October 4, 2006 by snowmaiden

[Stratos Ferric]

The first part of my post ws relating to a record year, I think the record is where October holds the key (given the very warm october last year and where we are in comparison right now etc)

As for compared to last year, its likely to be marginal either way, probably so much so that it remains on the 4 year 'plateau' we appear to be on.

A cranked up El Nino next year will make for some intersting assessment if we can get it going!

I am not trying to point to potential cooling btw, more a fascination in a possible decrease for another year however minimal with 2 record months in the bag.

My thinking is that were this to continue (on a plateau) with warmer summers then one might start thinking in terms of changes to summer and winter and the influences therein.

Another way of looking at it is to say that last year only became a cooler year (c.f. the one before) because of unusual (in modern terms) coolness in November and December, that's why I'm of the view that October is immediately more relevant for a record year than a warmer year, but either way it resolves nothin on its own. We could "afford" a cooler October than last year and still beat last year, and the annual record, simply by either November or December coming in fairly warm. For the reasons I've already outlined previously this latter is probably more likely than a warm October would be, even without looking at the set up for the next few days. A Nov-Dec combo like last year would probably not attract a book at all, so unlikely is the same sort of net cold. If you assume that Nov-Dec are up on last year, then given the 0.7C in hand, October could afford to be a lot cooler than currently looks likely and we'd still end up up on the year, and probably nudging the record.

If we do end up with another cooling year then it will equal the longest run of cooling on the books, though given that the cumulative cooling will still be very close to the rounding error I'm not sure that it would be indicative of anything much. The four previous instances produced cooling of between about 1.2 and 3.5C. In all instances pronounced cooling in spring and early summer was present, just like recent times - not.

[Snowly does it]

Another way of looking at it is to say that last year only became a cooler year (c.f. the one before) because of unusual (in modern terms) coolness in November and December, that's why I'm of the view that October is immediately more relevant for a record year than a warmer year, but either way it resolves nothin on its own. We could "afford" a cooler October than last year and still beat last year, and the annual record, simply by either November or December coming in fairly warm. For the reasons I've already outlined previously this latter is probably more likely than a warm October would be, even without looking at the set up for the next few days. A Nov-Dec combo like last year would probably not attract a book at all, so unlikely is the same sort of net cold. If you assume that Nov-Dec are up on last year, then given the 0.7C in hand, October could afford to be a lot cooler than currently looks likely and we'd still end up up on the year, and probably nudging the record.

If we do end up with another cooling year then it will equal the longest run of cooling on the books, though given that the cumulative cooling will still be very close to the rounding error I'm not sure that it would be indicative of anything much. The four previous instances produced cooling of between about 1.2 and 3.5C. In all instances pronounced cooling in spring and early summer was present, just like recent times - not.

I do see where you are coming from here entirely, I thought Nov and Dec were closer to average - they are in some ways but not the shorter term averages, so OK, record year dependant on October in the main, but not out of reach regardless.

I suppose if it does plateau, the key really is where the next big move goes, there is only one favourite for that right now.

[summer blizzard]

November and December 2005 were both 0.7C below average if i am not mistaken.

That means that if November and December 2006 were average, October 2006 would need a CET of no more than 11C just to equal the 2005 yearly CET, something which is not out of the question, given the recent model runs.

[Optimus Prime]

What's the chance of getting the warmest year ever? I would say after a 'stonkingly' mild Octover (now extremely likely) what would it take for November and December to turn around a yearly CET above all those other record breaking months recently? (I.E 10.63c)

[Weather-history]

What's the chance of getting the warmest year ever? I would say after a 'stonkingly' mild Octover (now extremely likely) what would it take for November and December to turn around a yearly CET above all those other record breaking months recently? (I.E 10.63c)

To equal that it would require the last 3 months of the year to have a CET average of 8.42. That has only been achieved on 7 occasions

[West is Best]

What's the chance of getting the warmest year ever? I would say after a 'stonkingly' mild Octover (now extremely likely) what would it take for November and December to turn around a yearly CET above all those other record breaking months recently? (I.E 10.63c)

If October does come in at say 13C, then the answer is that a combined CET for November and December of 12.27C (i.e. average of above 6.13C) will take the record. That's easily possible, but I'm nervous about even suggesting such a thing with two and a half months to go. The Met O stuck their necks out last year with only a couple of weeks left, and ended up with a little egg on face. However, 12.27C or, say, 7C and 5.3C for November and December would be more than possible ...

To equal that it would require the last 3 months of the year to have a CET average of 8.42. That has only been achieved on 7 occasions

True Kevin, but if you factor in October's likely warmth ...? How often has Nov-Dec averaged 6.13C or above? A lot more often I think ...?

Edited October 16, 2006 by West is Best

[Weather-history]

...

True Kevin, but if you factor in October's likely warmth ...? How often has Nov-Dec averaged 6.13C or above? A lot more often I think ...?

Yes there have been more times although last November/December wasn't one of them

[Weather-history]

Warmest 12 month period is November 1994- October 1995 with 11.07C. The next 7 months (October-April) would need a CET average of 7.43 to equal it

If you add April 2006 to that then the next 6 months (October-March) would need to average about 7.23C

Edited October 16, 2006 by Mr_Data

[reef]

Here are the average temperatures required during October 01 - December 31 to give the following yearly CET values:

Snow-Man: 2006: 9.35C 3.25

Optimus Prime: 9.6C 4.29

Snowmaiden: 9.7C 4.69

Wilson: 9.75C 4.89

Anti-Mild: 9.95C 5.69

Kold Weather: 9.99C 5.85

Sunshine: 10.00C 5.89

West Is Best: 10.02C 5.97

Pete Tattum: 10.03C 6.01

Thundery Wintry Showers: 10.08C 6.21

AtlanticFlamethrower: 10.11C 6.33

Bham Chris: 10.14C 6.45

Summer Blizzard: 10.15C 6.49

Stargazer: 10.16C 6.53

Mr Sleet: 10.25C 6.89

Dawlish: 10.40C 7.49

Rollo: 10.50C 7.89

Reef: 10.55C 8.09

Wilson: 11.00C 9.89

For reference, the October 01 - December 31 average is 7.47°C.

Edited October 16, 2006 by reef

[Guest Mike W]

I think reef may be nearer the mark, although the way things have acclerated Wilson's may not be out of the picture at this rate for next year at least.

[Optimus Prime]

Just wondering what the chance of a CET below 9.0c is? the 1900's didn't have a single yearly CET below 8.0c, yet in the 1800's there were several years below 8.0c and 7.0c.

In my opinion it's almost a non-existant chance, 9.0c will become the new cold (e.g 8.0 for the 20th century) and 10.0c will become the new average (9.0c for the 20th century) And I suspect 11.0c will occasionally pop up, much like 10.0c did in the 20th century.

[reef]

Just wondering what the chance of a CET below 9.0c is? the 1900's didn't have a single yearly CET below 8.0c, yet in the 1800's there were several years below 8.0c and 7.0c.

In my opinion it's almost a non-existant chance, 9.0c will become the new cold (e.g 8.0 for the 20th century) and 10.0c will become the new average (9.0c for the 20th century) And I suspect 11.0c will occasionally pop up, much like 10.0c did in the 20th century.

If the average is taken from post-1988 (possibly agreed as the 'point' when it suddenly became milder), then the average is 10.20°C. Using such numbers puts 1996 (9.20°C) exactly a degree below average. I think it is becoming rare to have such sustained cold to allow a CET around the 9°C mark. Indeed, we're lucky to record a sub-10°C CET these days.

1988-2005 averages:

JAN: 4.9°C

FEB: 5.1°C

MAR: 7.1°C

APR: 8.5°C

MAY: 11.9°C

JUN: 14.5°C

JUL: 16.7°C

AUG: 16.8°C

SEP: 14.1°C

OCT: 10.7°C

NOV: 7.1°C

DEC: 4.9°C

YEAR: 10.20°C

Although the 1988-2005 period is a random selection of years, Id say its probably accurate these days as an average. As always, time will tell.

[Optimus Prime]

I think the only months we can argue are;

April; Too low

May; About right

June; Way too low!

August; About right

September; Too low

October; Too low

November; Too low

December; Touch too high

Just by guessing, these days it should look a little like this;

January; 5.0c

February 5.0c

March; 7.0c

April; 8.8c

May; 11.8c

June; 15.1c

July; 17.0c

August; 16.9c

September; 14.2c

October; 10.8c

November; 7.6c

December; 4.7c

Yearly average 10.3c

I think 10.3c would be a good benchmark in our current climate.

Once December eventually starts warming up massivelyg like october, the yearly CET will really shoot up.

[Guest Mike W]

the Manley 1988-05 average as has been said is 10.20. The Hadley average for this time frame is 10.19. I persoanlly think 1997 - 05 is a more better representation of where we are in terms of a baseline annual CET as I think 1997 was where the warming accelerated further with a big help from the clean air laws here and other countries. Controversy aside it was also the start of 4 10.00's in a row which repeated itself in 2002 - present and of course will be broken by 5 in row when this year finishes at 10.** and this year may end up being the hottest annual CET on record until it gets beaten again soon. Manley 97 - 05 is 10.42, Hadley average for 97-05 is the same. 10.42 as an average is motre realistic than 10.20 IMO.

Edited October 18, 2006 by Mike W

[chilly milly]

Just out of interest would anyone be able to quote how many Yearly CET's were over 10C over the last century breaking in down into quarters. Ie 1900 - 1925, 1926 - 1950, etc bring it up to date. Just curious, thank you.

[reef]

Just out of interest would anyone be able to quote how many Yearly CET's were over 10C over the last century breaking in down into quarters. Ie 1900 - 1925, 1926 - 1950, etc bring it up to date. Just curious, thank you.

1900-1925 - 2

1926-1950 - 5

1951-1975 - 3

1976-2000 - 10

2001-2005 - 4 so far

[chilly milly]

Oh Wow!!! Thanks for that Reef. Kinda speaks for itself doesn't it.

[VillagePlank]

Just wondering what the chance of a CET below 9.0c is? the 1900's didn't have a single yearly CET below 8.0c, yet in the 1800's there were several years below 8.0c and 7.0c.

In my opinion it's almost a non-existant chance, 9.0c will become the new cold (e.g 8.0 for the 20th century) and 10.0c will become the new average (9.0c for the 20th century) And I suspect 11.0c will occasionally pop up, much like 10.0c did in the 20th century.

Sounds about right. Although, taking on board current GW stats, I'd lower the base mean to about 9.7 to include any rogue cold months (which, of course, are still entirely possible) This also includes the possibility of the last few years being a warm anomaly, with a correction to a higher base mean as expected from people like the Hadley centre.

[smich]

But shouldn't all these CET stats be scaring the pants off us?!

This summer, just using the NW tracker figures we have:

June +2.7c

July +3.5c

Sept +2.8c

Oct +2.5c

...above average.

These are ridiculous anomalies really, August wasn't even that bad (especially given the synoptics).

I'd always thought 2.0c above average over the course of a whole month was extreme, but that must be old school thinking I guess!

Smich

[West is Best]

as expected from people like the Hadley centre.

Do you think you could refrain from comments like this? Carping against one of the leading climate research institutes in the world makes you (and the rest of us) look a little below par. If you don't like the work Hadley are doing post something sensible, by which I don't mean re-hashed graphs with erroneous datelines. Seriously, the Hadley centre have some of the best scientists around working for them in conjunction with leading Universities in the world, and to put it bluntly a criticism like that on a forum like this doesn't do any of us good. At least be constructive about it.

Edited October 18, 2006 by West is Best

[summer blizzard]

Going by the 1970-2000 data, deviations from average are as follows (Hadley CET)...

January: +0.1C

February: -0.5C

March: -1.4C

April: +0.5C

May: +1C

June: +1.8C

July: +3.2C

August: -0.1C

September: +3.1C

[Stratos Ferric]

But shouldn't all these CET stats be scaring the pants off us?!

This summer, just using the NW tracker figures we have:

June +2.7c

July +3.5c

Sept +2.8c

Oct +2.5c

...above average.

These are ridiculous anomalies really, August wasn't even that bad (especially given the synoptics).

I'd always thought 2.0c above average over the course of a whole month was extreme, but that must be old school thinking I guess!

Smich

If I remember at the w/e I'll analyse the variation against the SD for each month and then test the combination to see just how unusual the year has been in terms of relative deviation, though it is almost certainly safe to say that it will be an unusual year, particularly so if October comes in as high as looks likely.

[Terminal Moraine]

But shouldn't all these CET stats be scaring the pants off us?!

This summer, just using the NW tracker figures we have:

June +2.7c

July +3.5c

Sept +2.8c

Oct +2.5c

...above average.

These are ridiculous anomalies really, August wasn't even that bad (especially given the synoptics).

I'd always thought 2.0c above average over the course of a whole month was extreme, but that must be old school thinking I guess!

Smich

These anomalies are almost a mirror image of the negative anomalies experienced during the depths of the Little Ice Age, an indication of just how far from 'normal' the weather is at present.

In an environment where a succession of months with a 1.5c positive anomaly would barely raise an eyebrow it also begs the question, is the run of exceptional positve anomalies this year at the upper end of what can be expected or is this just routine and the real extremes will show monthly positve anomalies of 4-5c?.

The second question would be, is the climatic system (in our part of the world at least ) approaching a point of instability and how will this manifest itself?

In the not too distant future can we expect a succession of months with positive anomalies of 2-4c or will there be dramatic fluctuations between positive and negative? I mention this last point on the strength of the persistence of the meridional flow of late. We have been on the warm side for some time but it would seem, if not equally likely, at least possible that we could also fall on the cold side and if this were to be the case it could persist for some considerable time. We would then have a situation where a lengthy spell of dramatically positive months are followed by several months of equally dramatic negative anomalies.

All pure speculation on my part but, I think, quite possible.

Any thoughts on this?

T.M

[Rollo]

Morning T.M., being a total amateur my views must be treated with caution but when you say your views must be pure speculation then I must agree wholeheartedly. We appear to be on the cusp of completely different synoptics to those which I experienced in the sixties on and up to quite recent times. Mother nature has a way of levelling things out and I for one would not be at all surprised should a month occur this winter (probably out of the blue) which is between minus 2 or 3 below the long term norm.