Annual CET 2007

[Stratos Ferric]

If Hadley confirms at 15.1C then we have only 6.4 cumulative degrees in hand of last years values to see 11C breached.

Statistically over half of that is likely to disappear in July which makes 11C very much a longshot now considering we have no cold months to play with and another two (Sep/Oct) in the record or near record category.

In fact I would go as far to say that beating last year may (10.82) may now be odds against.

It's certainly a close call Stu. Whilst "statistically" there's an argument to say that we'll lose 3 degrees this July c.f. last, that's one particular use of "statistically" which rarely stacks up nowadays, i.e. we return an average month. By the end of July we're far more likely to have at least 4 degrees in hand on last year. Even that would require a positive anomaly against the ten year mean of just 0.5C, lower than most recent months have managed.

We then have August, which in the run since winter 2006 [August 2006] is the outlying month, even coming in as cold against the ten year mean. Whilst it's not impossible, personally I doubt that we will have three disappointing summer months, and therefore I'd expect August to come in higher than recent par. Admittedly it's pure conjecture, but on this basis come the start of September we should be at least 4.5 cumulative C to the good on last year. Those months last year were about 7.5C above par, so it would come down to a punt on whether we expected them to deliver a positive anomaly of 3.5C this time. It's not odds on, but I'd reckon short odds against, at present around 4 or 5 to 1 against 11.0C. The margin for another record breaker would be only about 1.3 cumulative C. That's been bettered in nine of the last ten years, and is comfortable odds on therefore, something like 5-2 on, or 3-1 on.

[Mr Sleet]

It's certainly a close call Stu. Whilst "statistically" there's an argument to say that we'll lose 3 degrees this July c.f. last, that's one particular use of "statistically" which rarely stacks up nowadays, i.e. we return an average month. By the end of July we're far more likely to have at least 4 degrees in hand on last year. Even that would require a positive anomaly against the ten year mean of just 0.5C, lower than most recent months have managed.

We then have August, which in the run since winter 2006 [August 2006] is the outlying month, even coming in as cold against the ten year mean. Whilst it's not impossible, personally I doubt that we will have three disappointing summer months, and therefore I'd expect August to come in higher than recent par. Admittedly it's pure conjecture, but on this basis come the start of September we should be at least 4.5 cumulative C to the good on last year. Those months last year were about 7.5C above par, so it would come down to a punt on whether we expected them to deliver a positive anomaly of 3.5C this time. It's not odds on, but I'd reckon short odds against, at present around 4 or 5 to 1 against 11.0C. The margin for another record breaker would be only about 1.3 cumulative C. That's been bettered in nine of the last ten years, and is comfortable odds on therefore, something like 5-2 on, or 3-1 on.

Last year we were under the influence ofa raging El Nino. Interesting to note this morning that the Met Office are going for a poor summer throughout due to an increasing La Nina signal. My point is that there is no way the annual CET will reach 11C or higher.

Edited July 2, 2007 by Mr Sleet

[Roger J Smith]

If I were running a weather betting shop (and who isn't), I would probably set the over-under for the annual CET at 10.8 and give a 40% chance of breaking 11.0, 30% of 11.2 and 20% of 11.4. Same odds on the other side of the ledger, 40% below 10.6, 30% below 10.4, 20% below 10.2.

[West is Best]

If Hadley confirms at 15.1C then we have only 6.4 cumulative degrees in hand of last years values to see 11C breached.

Statistically over half of that is likely to disappear in July which makes 11C very much a longshot now considering we have no cold months to play with and another two (Sep/Oct) in the record or near record category.

In fact I would go as far to say that beating last year may (10.82) may now be odds against.

6.4C for 6 months is a heck of a lot though Stu isn't it? It's over a degree a month warmer. Yes, we have the July effect coming on, but surely this should be partly countered by August? I'd be surprised if this August is as cool as last year. It's worth bearing in mind that even this June was only 0.8C below last year.

I suppose though the real issue here is more about synoptics than statistics? Although most of us accept a generally warming trend, anything can happen. If you get poor synoptics it may be relatively warm, but not absolutely so. We could still easily get a December 2005 again to pinch things back a touch.

Edited July 2, 2007 by West is Best

[West is Best]

there is no way the annual CET will reach 11C or higher.

This is strong stuff Mr Sleet! Bold indeed!

On balance I'd say it's better than evens that we'll pip 11C: I'd go for 6-4 On.

[Stu_London]

If I was laying this I would say

10.82C or higher - 11/8

11C or higher - 6/1

10.5C or lower - 9/1

11.25C or higher - 20/1

10.25C or lower - 28/1

[West is Best]

Stu - just checked your figures in passing and I make it that this year to the end of June is 8.5C cumulative up on this time last year, not 6.4C. http://www.metoffice.gov.uk/research/hadle.../HadCET_act.txt

If the remaining months are just 1C above the 1971-2000 mean, which is statistically plausible, we will comfortably pass 11C

[DR Hosking]

agrred west is best. According to Hadley the cummulitative CET so far this year (first 6 months) is 58.2 degrees to reach a CET of 11, 11 x 12 months = 132 total degrees. 132 minus 58.2 degrees for the first 6 months leaves us with 73.8 degrees to play with for the remaining 6 months. If you add up the averages for the remaining 6 months it comes to 68.8. So 73.8 minus 68.8 degrees leaves us with 5 degrees to find above average for 6 months. So if the next 6 months are an average of 0.8333 degrees above average then we will hit 11 degrees cet.

[Stu_London]

agrred west is best. According to Hadley the cummulitative CET so far this year (first 6 months) is 58.2 degrees to reach a CET of 11, 11 x 12 months = 132 total degrees. 132 minus 58.2 degrees for the first 6 months leaves us with 73.8 degrees to play with for the remaining 6 months. If you add up the averages for the remaining 6 months it comes to 68.8. So 73.8 minus 68.8 degrees leaves us with 5 degrees to find above average for 6 months. So if the next 6 months are an average of 0.8333 degrees above average then we will hit 11 degrees cet.

Richard / Doctor

We seem to be working on different calculations.

The basis I am working on is in comparison to last year. We are indeed 58.2 to date in 2007. If the remaining months of 2007 matched those July to December 2006, the outrun would be 138.4 cumulative degrees. 132 cumulative degrees are required for 11C, so we need to be 6.4 below last year to be 11C.

Therefore last year has 6.4 cumulative degress in hand.

It sounds nailed on that 11C will be hit, however it should be remembered that none of the last 6 months of 2006 were cold, only one was average (Aug) and 3 were record breaking or close to it (Jul/Sep/Oct). That coupled with the current signal which if not cold, is more towards neutral leads me to believe that 11C won't be breached.

[West is Best]

Richard / Doctor

We seem to be working on different calculations.

The basis I am working on is in comparison to last year.

Erm ... well you may be Stu but not as I understand it. You may well have some other method of calculation that I haven't got my head round but a straight comparison of 1st Jan to 30th Jun shows we're 8.5C cumulative ahead this year.

The cumulative total to 1st July is as follows:

2007 58.2C

2006 49.7C

So this year is 8.5C above last year from 1st January until now.

[DR Hosking]

I see what your saying Stu, just a bit of an odd way round to work it out!

[Stu_London]

I see what your saying Stu, just a bit of an odd way round to work it out!

It's Stratos Ferric's fault - he got me thinking in them terms

[summer blizzard]

Taking April out of the equation, March, May and June have produced an average anomoly of 0.8C above average, which i will round up to 1C above average for good measure, so if we have 8.5C to play with, and each month came in 1C above average from now on, in November and December we would lose 0.5C to knock it down to 8C, and we would lose a further 4.3C during July and September to knock it down to 3.7C, also losing 1.6C in October to knock it down to 2.1C however the crucial month is August, because we are likely to see a gain, so that we end up 3C above last year cummitively, we would also pass the 11C mark.

[SP1986]

I find this interesting, if we take the net-weather temperature trackers own CET values from months just gone then you have:

J = 7 (+)

F = 6 (+)

M = 7 (+)

A = 11 (+)

M = 12 (+)

J = 15 (+)

-----------

J = 16 (-)

A = 16 (-)

S = 15 (+)

O =14 (+)

N = 10 (+)

D = 7 (+)

The numbers are mean temperature in degrees, the line is a possible scenario and the pluses and minuses mean above or below average respectively.

The mean temperatures for 2007 arent going to be far off these values give or take a degree each month. What staggers me from the years so far is how indifferent the difference between January and June actually is, it's like a stable climate. A CET rank like this is heading towards Azores territory.

If the mean temperatures end up similar to this, I will sit up (rather fast)

It's really interesting how in one sense it might be one of the warmest years on record if this scenario occurred

In fact this scenario would lead to a CET of 11.3°C (which would be a record, I believe)

[Stu_London]

11.3C is achieved if we combine the warmest ever 1st half of the year (2007) with the warmest ever 2nd half of a year (2006)

Unlikely, with signals as they are that the second half temps of 2007 will be anywhere near those of 2006.

July looks long odds on the be the first below average month for over a year and if August is only about average then chances of even hitting 11C are toast in my honest opinion.

[Snowly does it]

July looks long odds on the be the first below average month for over a year and if August is only about average then chances of even hitting 11C are toast in my honest opinion.

Last August was below average.

Lets say for the sake of argument that July and August come in at 16 each.

That would require the last 4 months of the year to come in at a total of 41.8 to reach 11

If Sept and Oct came in lower than last year at around say 15 and 12 it would leave 14.8 required for November and December - maybe 8 for Nov? Leaves 6.8 for December

Sorry, thinking out loud here but IF we get below average July and August at 16 I would still fancy 11 being hit (just)

[Stu_London]

Sorry, thinking out loud here but IF we get below average July and August at 16 I would still fancy 11 being hit (just)

If we were sitting here with the same signals as 2006 I would have to agree.

I suspect even allowing for a slight warming undertrend, that things are very different this year, hence the analysis

[summer blizzard]

Ignoring April, since March we have not seen a month average more than 1C above average, and i do not expect the second half to average more than 1C above average, thus, i would be suprised if we record an 11+ annual CET.

[Snowly does it]

If we were sitting here with the same signals as 2006 I would have to agree.

I suspect even allowing for a slight warming undertrend, that things are very different this year, hence the analysis

I see what you're saying, I'd certainly still be backing a record year even if 11 wasn't breached, but I think I'd need to see August and Sept before I thought further than that.

[Toppler]

Ignoring April, since March

:rolleyes:

You just can't ignore a months data.

[Stu_London]

You just can't ignore a months data.

:lol: :lol: :lol:

I agree

However it was a freakish month, more so when you consider what surrounds it. The warmest April of all time - and a dry month in what looks like having 3 very wet months either side - not just a dry month, one of the dryest ever.

[summer blizzard]

I agree

However it was a freakish month, more so when you consider what surrounds it. The warmest April of all time - and a dry month in what looks like having 3 very wet months either side - not just a dry month, one of the dryest ever.

The driest month since August 1995.

[Gavin P]

I agree with Summer_Blizzard here. I think theres enough residual warmth on the Continent to pose a threat of above average temps for the remainder of this summer, but overall, I think the secind half of 2007 is going to be one of much more stable and slowly declining CET's. I expect rainfall amounts to continue to be well above average, at times maybe exceptional, but I think we've done with the record breaking warmth for this year. CET, to come in somwhere around 10.5 to 10.7, IMO.

[summer blizzard]

I agree with Summer_Blizzard here. I think theres enough residual warmth on the Continent to pose a threat of above average temps for the remainder of this summer, but overall, I think the secind half of 2007 is going to be one of much more stable and slowly declining CET's. I expect rainfall amounts to continue to be well above average, at times maybe exceptional, but I think we've done with the record breaking warmth for this year. CET, to come in somwhere around 10.5 to 10.7, IMO.

Ypu've got me wrong, my point was that even if the second half of 2007 averaged 1C obove, we would still only just pass 11C, my personal expectations are for a chilly first half to Autumn especially and a non-descript summer.

[Stratos Ferric]

...

July looks long odds on the be the first below average month for over a year and if August is only about average then chances of even hitting 11C are toast in my honest opinion.

I think it's a little early to call that just yet. Though the odds on a below average month are better than they've been since last August, I wouldn't desribe them as "long odds-on".