September CET!

[SP1986]

It doesn't but statisically September is still more likely to become progressively cooler as the month goes on regardless of what has happened previously.

Therefore to maintain a level that is above average for the month as a whole, means that as time goes by, you need to be further and further above the mean just to maintain the level. The model output seems to be suggesting the reverse of that, although as SF says (quite correctly) the warmer stuff is in the more relaiable timeframe, which means the probability of a warm month as a whole is that much greater.

Stu, you could have said that about April. The fact that the month starts with a lower average than the end of the month, should have resulted in something lower, but it didnt - instead it resulted in something high, which in fact I think stuck at 11C nearly all month.

There is by no means any certainty and you are right in that you say temperatures to fall, but thats really means nothing - the drop is nothing compared to the drop in October so therefore 15C (around 2C above average) is possible.

Having said that I doubt it will happen, I'm actually very pleased with my current punt of 14.3 but 15+ is possible, there's no denying that.

[summer blizzard]

Stu, you could have said that about April. The fact that the month starts with a lower average than the end of the month, should have resulted in something lower, but it didnt - instead it resulted in something high, which in fact I think stuck at 11C nearly all month.

There is by no means any certainty and you are right in that you say temperatures to fall, but thats really means nothing - the drop is nothing compared to the drop in October so therefore 15C (around 2C above average) is possible.

Having said that I doubt it will happen, I'm actually very pleased with my current punt of 14.3 but 15+ is possible, there's no denying that.

Stephen, April did actually start on quite a cool note, however you are right in saying that by mid-month, the CET was already 10C+, so it only rose by another 1C...

In reference to this month, we do actually have the perfect synoptics for a high outur because high pressure over us does not depend on whether we are in a cold or warm sector, as the level of solar radiation wont fall significantly, the change from the current synoptics now, to being repeated at the end of the month would be minimal, though i don't believe the secon half will exceed the first, thus i think 15C is on the high side, but still possible.

[The PIT]

Well today should have given a huge push upwards and this should continue into the weekend. After Monday Tuesday it may cool down a bit or the models may decide to keep the High around longer.

[West is Best]

Well today should have given a huge push upwards and this should continue into the weekend. After Monday Tuesday it may cool down a bit or the models may decide to keep the High around longer.

Yes I can see this high being very stubborn actually. It doesn't really go anywhere on the 12z GFS. A little jiggle from one foot to the other but ends up in the same place. Just got a nasty feeling it's going to take some shifting.

Edit - oops meant to put that in the model thread.

Some 25C's today.

Edited September 6, 2007 by West is Best

[shuggee]

Yes - it's certainly traditionally settled September weather - all we need now is the low minimums back, and if the high moves west a little to allow a northern component to the breeze, I suspect that might produce.

It's well known up here that if you want to visit the Highlands - do so in May or September.

[Michael Winston]

Hi, all. Hope this finds everyone well. (Back from a great holiday in Italy.)

I don't know what the CET will be but if Metcheck's daily weather e-mail for today is to be believed then their predicted temperature in the range of - 250C and rainfall of 228mm for Birmingham might bring it down a bit if it comes off!!!!!!

Kind regards,

Mike.

[SP1986]

Yes - it's certainly traditionally settled September weather - all we need now is the low minimums back, and if the high moves west a little to allow a northern component to the breeze, I suspect that might produce.

It's well known up here that if you want to visit the Highlands - do so in May or September.

Unfortunately judging by the amount of Midges (and Mosquitoes) here today, well you'd have to carry sme repellant with you

[Stratos Ferric]

It doesn't but statisically September is still more likely to become progressively cooler as the month goes on regardless of what has happened previously.

...

Stu, in general you're quite correct, however all should note that if you happen to use Philip's site for the running score, he already corrects for monthly ebb and flow. Hence, if he is currently showing +1.5C, this would actually be closer to being, say, +2.5C when compared to the average for September as a whole.

Well today should have given a huge push upwards and this should continue into the weekend. After Monday Tuesday it may cool down a bit or the models may decide to keep the High around longer.

What was striking last night was how warm it stayed in the north. Manchester stayed up around 15C. This early in the month, whilst the leverage of each day is large towards the current average, I'd expect a big upswing towards the start of next week. Getting up around 16C is very likely, in which case, with a third of the month gone, a sub-par outcome would start to seem highly improbable.

...In reference to this month, we do actually have the perfect synoptics for a high outur because high pressure over us does not depend on whether we are in a cold or warm sector....

Not as perfect as last September. The difficulty with a HP is that subtle changes in location, and then cloud cover, can make for large differences. Alos, whilst frontal boundaries are weak, we can also still get air mass changes. Earlier this week we had some polar air in the mix, what we have now is decidedly tropical.

[The PIT]

Well last night nearly made it surprisingly to single figures just stopping at 10C but not lower enough to prevent a way above average day.

[Kentish Man]

The updated Manley CET is 15.5C (Sep 1- 6)

[Stu_London]

The updated Manley CET is 15.5C (Sep 1- 6)

Bit suspicious of that because if you add the maxes and mins average, you come up with 15.25C

I wonder if an error is contained in there somewhere.

[West is Best]

Bit suspicious of that because if you add the maxes and mins average, you come up with 15.25C

I wonder if an error is contained in there somewhere.

Well spotted Stu.

It's also WAY below Hadley. The latter was on 15.5C after Wednesday's data, so will be nearer 16C by now. It's very unusual for the two to be so far apart.

[kold weather]

Could be an isolated site keeps getting lower readings which is helping to drag the average down a little compared to the Hadley.

Whatever it is this month should be above average, yeah its a little to say for sure but the synoptic pattern won't change al lthat much for at least the next 15 days which should take us up to the last week of the month and by which point even if we do have a decent cool-down it'll be too much for it to drag the CEt below. Probably looking at the eventual CET being between 15-16.5C.

Edited September 7, 2007 by kold weather

[West is Best]

Could be an isolated site keeps getting lower readings which is helping to drag the average down a little compared to the Hadley.

Indeed Kold. That's one reason I prefer Hadley - namely that they use a number of other sites to verify the three main ones. I think that's on balance the right approach, certainly in terms of taking the CET forward as a reliable measure in the future even if it does raise some issues about comparing to the past.

[Lettucing Gutted]

I can see no connection meteorological between a mild September and a mild winter. 1985/6 is a good example of how the connection doesn't work. 01st October 1985 was virtually 30C, only to find Feb 1986 recording a staggering -1.1C for the month: since 1947 only one other month has ever been colder. Not even the winter of 1978/9 produced a month as cold as Feb 1986. And I remember it vividly, just as I remember (quite honestly) sunbathing on 02nd October 1985 in London.

At the moment I'm confident that any recent trend of warm Septembers and mild winters is nothing more than a quirk that has no scientific basis. 1985/6 very much suggests that to be the case.

Last night was milder than expected owing to cloud cover.

The problem with that West is Best is that Britain wasn't experiencing year round warming as frequent as now before 1988. We have re-based dramatically and frighteningly upwards since 1988 due to year round warming and we could yet again re-base even further above 1996/1997.

Edited September 7, 2007 by Craig Evans

[West is Best]

The problem with that West is Best is that Britain wasn't experiencing year round warming as frequent as now before 1988. We have re-based dramatically and frighteningly upwards since 1988 due to year round warming and we could yet again re-base even further above 1996/1997.

OK - but can we have some metereology behind it? I could envisage some along the lines of SSTs or something, but at the moment this just looks to me like one of SF's spurious correlations.

By the way 1985 was even more stark than I had mentioned. I was sunbathing on 02nd October 1985, having just missed 30C the previous day, and then we had the coldest November of the last 100 years - it was bitterly cold. So is someone really suggesting to me that the switch that happened then in the space of 4 weeks is somehow impossible now? Why?

Smacks to me I'm afraid of complete tosh!

[Lettucing Gutted]

Probably looking at the eventual CET being between 15-16.5C.

If that comes off then 2007 could be the warmest year on record at least in the C.E.T zone. A very dangerous possibility that the warmest year on record could be broken again within just the space of a year after the previous one...

[Weather-history]

Septembers whose CET was greater than the summer's CET

1729, 1730, 1784, 1795, 1821, 1843, 1865, 1890, 1895, 1898, 1929, 1956, 1961, 1985

[DR Hosking]

If that comes off then 2007 could be the warmest year on record at least in the C.E.T zone. A very dangerous possibility that the warmest year on record could be broken again within just the space of a year after the previous one...

To beat last year the anomaly must be higher than 1.43 for the remainder of the year. So we would need mild October, November and December too, cant see it happening myself.

[West is Best]

Septembers whose CET was greater than the summer's CET

1729, 1730, 1784, 1795, 1821, 1843, 1865, 1890, 1895, 1898, 1929, 1956, 1961, 1985

Hi Kevin,

Think I follow that - but still only 1890 has had September as the actual warmest month of the year?

Any comments on my 25C thread? Would love some hard data on it if you have it?

Richard

[Stratos Ferric]

If that comes off then 2007 could be the warmest year on record at least in the C.E.T zone. A very dangerous possibility that the warmest year on record could be broken again within just the space of a year after the previous one...

The emphasis, Craig, must be on the 'could'. Last year's record breaking year, though founded on a very warm June (remember the year started cold by recent standards), was delivered by an astonishingly mild autumn. Waters around the UK are warming quickly again, and if this continues a mild autumn looks more probable, but I'd be astonised to see anything as consistently very warm as last autumn was. As I've mentioned in the annual CET thread, the real inerest now is probably around whether we establish a new no.2 on the all time CET list.

[The PIT]

Climate UK has it 15.5C for the 1st to the 6th which seems a bit low. We're 2.1C above normal here so the CET zone must have had some really cold nights.

[Stu_London]

From www.climate-uk.com

To the 7th September - 15.7C

Although we still have mildish nights, I think any upward movement in the 2 days will be minimal. Then over the next few days, some drops with low minimas. After that, who knows, if the ECM verifies, then further falls are likely.

I think the usual suspects calling high 15s and 16s may have overegged the warmth again.

I think above average is about 95% certain

Above 15C - I would only say 45%

Edited September 8, 2007 by Stu_London

[West is Best]

I think the usual suspects calling high 15s and 16s may have overegged the warmth again.

No-one in the competition has called for anything in the 16's, and only Rodger J Smith and Reef have called for high 15's, and I'd hardly call them usual suspects. To be fair Craig has gone for 17C. Perhaps you were thinking of him.

No real sign of a drop on the GFS. Those hoping for autumn are reliant at the moment on the ECM being right, otherwise we're going to have to put up with this unusually warm month chugging on and off along the 15.5C to 16C sort of range.

[Roger J Smith]

I don't know who this Rodger J Smith is, but Reef seems like a sensible guy. :unsure: