September 2009 Cet

[Stu_London]

14.5 to the 16th

[SteveB]

14.4c to the 17th 0.2

[Stu_London]

14.4C to the 18th (18th came in at 14.4C exactly)

GFS 06z suggests an outcome before adjustments of 13.9C

Therefore we will probably be just above the 61-90 and 71-00 averages and last years figure, however we would be below the 10 year rolling average of 14.7C

[The watcher]

Stay at 14.4c, that was my punt

[Stu_London]

CET back up to 14.5C today.

Today's GFS 06z would suggest a final outcome before adjustments of 14.1C

[DAVID SNOW]

CET back up to 14.5C today.

Today's GFS 06z would suggest a final outcome before adjustments of 14.1C

14.1... That will do for me

[reef]

Hadley back down to 14.4C to the 20th. Yesterday averaged 14.0C.

[damianslaw]

At this juncture in the month and going off the projected synoptics, you would bet on a finishing figure somewhere at or just below the 14 degree mark, however, if we do a see a northerly plunge to end the month a mark more closer to 13.5 - 13.7 range could be on the cards - absolute bottom line I will say is 13.5 with top as it is now. So likely to be another near average CET.

[Fozfoster]

At this juncture in the month and going off the projected synoptics, you would bet on a finishing figure somewhere at or just below the 14 degree mark, however, if we do a see a northerly plunge to end the month a mark more closer to 13.5 - 13.7 range could be on the cards - absolute bottom line I will say is 13.5 with top as it is now. So likely to be another near average CET.

13.9 thats me and i said warm autumn then cold winter

Edited September 22, 2009 by fozfoster

[damianslaw]

13.9 thats me and i said warm autumn then cold winter

A finishing mark of 13.9 degrees would only be slightly above the average CET, so if the finishing mark and it is a good bet then this autumn will have started on a very average note not a warm one.

[Fozfoster]

A finishing mark of 13.9 degrees would only be slightly above the average CET, so if the finishing mark and it is a good bet then this autumn will have started on a very average note not a warm one.

Your right fella, but two out of three aint bad. I wish.

Edited September 23, 2009 by fozfoster

[The PIT]

14.4C at the moment but may go up a little in the next few days depending on night time cloud cover.

[North-Easterly Blast]

A question for Kevin Bradshaw (Mr Data)

As the second half of September in most years is cooler than the first half, I would be grateful if you could list the Septembers since World War 2 which had a warmer second half than the first half?

Correct me if I am wrong Kevin, but I believe that the last time September had a warmer second half than the first half was 1992.

[Stu_London]

14.4C at the moment but may go up a little in the next few days depending on night time cloud cover.

There may be the odd day where the value is slightly in excess of the running average but probably not enough to move it up. The trend to the end of the month is down slightly with a figure before adjustments of 14.1C likely according to the 12Z

[North-Easterly Blast]

Continuing the trend of the lack of cool weather in September since the mid 90s, again we avoid a cold September. It is now 15 years since the last significantly below average September (1994). More recently the relatively cool Septembers of 2001 and 2008 were only very slightly below both the 61-90 and 71-00 averages, by 0.2 or 0.3 at the most. No cool September for 15 years now. Just staggering! Will we ever see a cool September EVER AGAIN?

I for one do not see the point of getting late summer warmth when it is dark at 7.30 or even 7pm in the evening, it is just a waste of time as you have not got the long warm evenings to sit out in or do things outside in during September like you have during the summer months and even during May.

[Don]

Continuing the trend of the lack of cool weather in September since the mid 90s, again we avoid a cold September. It is now 15 years since the last significantly below average September (1994). More recently the relatively cool Septembers of 2001 and 2008 were only very slightly below both the 61-90 and 71-00 averages, by 0.2 or 0.3 at the most. No cool September for 15 years now. Just staggering! Will we ever see a cool September EVER AGAIN?

I for one do not see the point of getting late summer warmth when it is dark at 7.30 or even 7pm in the evening, it is just a waste of time as you have not got the long warm evenings to sit out in or do things outside in during September like you have during the summer months and even during May.

That is indeed a long period. When you think that last September felt relatively cool, imagine how cool a September would feel now if we had one like 1993 and 1994! Mind you with the not so long ago scorching September 2006, it's hardly a suprise that last year felt quite cool. As to whether we will have a cool September again, I'm sure we will at some stage, but when that will happen is anyone's guess. I personally would like a proper cool September as I agree that warmth at this time of the year is a waste with the rapidly shortening days. Also, more importantly, I don't think that warm September's bode well for the following Winter these days.

Edited September 23, 2009 by Don

[North-Easterly Blast]

That is indeed a long period. When you think that last September felt relatively cool, imagine how cool a September would feel now if we had one like 1993 and 1994! Mind you with the not so long ago scorching September 2006, it's hardly a suprise that last year felt quite cool. As to whether we will have a cool September again, I'm sure we will at some stage, but when that will happen is anyone's guess. I personally would like a proper cool September as I agree that warmth at this time of the year is a waste with the rapidly shortening days. Also, more importantly, I don't think that warm September's bode well for the following Winter these days.

I especially think that there is a bit of a link between a warm September and a mild winter, and that a warm September does not favour a cold winter to follow. Winter rarely is colder than average after a warm September. Winters that follow warm Septembers are often warm or average at best. However, whilst there appears to be some link between warm Septembers and mild winters, I cannot see that there is any link the other way round (ie cold September = cold winter). From the records, probabilities appear to be finely balanced between whether or not a cold winter follows a cool September, whereas after a warm September, all the odds appear to be stacked in favour of an average to mild winter to follow.

Before anyone mentions the warm dry October = cold winter theory, there appears to be some truth to it in recent deacades (1995, 1985, 1978, 1969 etc), but prior to the 1950s I can not see much of a link to this theory.

The lack of cool Septembers in the last 15 years is similar to the trend of a lack of cool Augusts, Junes, Mays, Aprils and Februarys. It is now driving me up the wall that we cannot seem to be able to achieve a CET below average in September any more, ie 13.0*C or cooler. I am just sick to death of warm Septembers. Although this September has not been cool by a long way, admittedly it has not featured the sort of hot spells like Sept 2006, early Sept 1999, 2004, 2005 or mid Sept 2003 that had become common in most Septembers since around 1997.

[Stu_London]

I especially think that there is a bit of a link between a warm September and a mild winter, and that a warm September does not favour a cold winter to follow. Winter rarely is colder than average after a warm September. Winters that follow warm Septembers are often warm or average at best. However, whilst there appears to be some link between warm Septembers and mild winters, I cannot see that there is any link the other way round (ie cold September = cold winter). From the records, probabilities appear to be finely balanced between whether or not a cold winter follows a cool September, whereas after a warm September, all the odds appear to be stacked in favour of an average to mild winter to follow.

Before anyone mentions the warm dry October = cold winter theory, there appears to be some truth to it in recent deacades (1995, 1985, 1978, 1969 etc), but prior to the 1950s I can not see much of a link to this theory.

The lack of cool Septembers in the last 15 years is similar to the trend of a lack of cool Augusts, Junes, Mays, Aprils and Februarys. It is now driving me up the wall that we cannot seem to be able to achieve a CET below average in September any more, ie 13.0*C or cooler. I am just sick to death of warm Septembers. Although this September has not been cool by a long way, admittedly it has not featured the sort of hot spells like Sept 2006, early Sept 1999, 2004, 2005 or mid Sept 2003 that had become common in most Septembers since around 1997.

Pattern matching Autumn CET to winters is a mugs game

for 2 reasons

1) September weather patterns have very little effect on winter

2) Using just the CET value is an extemely narrow data range. It tells you nothing about pressure patterns, NAO, AO and SSTs which arguably might give a signal for the next season. Also because it is restricted to a calandar month, it is unreliable in itself. Novemeber 2005 for example looks pretty average, but had one of the mildest 1st halfs and a very cold second half.

[Stu_London]

No change to the 23rd (14.4C)

Expect to see it down to 14.3C tomorrow

[SP1986]

Although not official, my own temperature data is pretty much indicative of the situation thus far across the CET area. My personal station data is registering 14.5 as a mean so far, and my suggestion is locally at least it will finish between 14.2 and 14.6.

Further south with the promise of chilly nights within the CET zone, the official reading may more like 13.8 to 14.0, I feel.

[Fozfoster]

Come on 13.9

[The PIT]

Although not official, my own temperature data is pretty much indicative of the situation thus far across the CET area. My personal station data is registering 14.5 as a mean so far, and my suggestion is locally at least it will finish between 14.2 and 14.6.

Further south with the promise of chilly nights within the CET zone, the official reading may more like 13.8 to 14.0, I feel.

That's the crux clear skies or not. Cloudy at night there won't be much swing as any drop in the day time temps will be offset by the rise in the night time temps.

[Optimus Prime]

Recently the mornigns have been cloudy but have cleared around 6 ish as the suns coming up allowing for temperatures to drop very quickly. A couple of nights ago it was 12.7c at 4:00 but still managed to drop to 8.4c.

[Stu_London]

No change to the 23rd (14.4C)

Expect to see it down to 14.3C tomorrow

As predicted, 14.3 to the 24th after yesterday came in at 12.5

A similar outcome likely today, but I don't think it will be enough to get us to 14.2 by tomorrow - maybe by 26th.

[Thundery wintry showers]

I especially think that there is a bit of a link between a warm September and a mild winter, and that a warm September does not favour a cold winter to follow. Winter rarely is colder than average after a warm September. Winters that follow warm Septembers are often warm or average at best. However, whilst there appears to be some link between warm Septembers and mild winters, I cannot see that there is any link the other way round (ie cold September = cold winter). From the records, probabilities appear to be finely balanced between whether or not a cold winter follows a cool September, whereas after a warm September, all the odds appear to be stacked in favour of an average to mild winter to follow.

September 1955: warm, sunny and dry. Followed by exceptional cold in February 1956, also very snowy in the east.

September 1981: warm, sunny and wet. Followed by exceptional cold in December 1981 and early in January 1982.

Also, before anyone starts on the "cold October=warm winter" theory, the Octobers of 1955 and 1981 (1981 especially) were on the cold side as well.