August has been another rather disappointing month. There was some reasonable weather in the south for a while but the latter part of the month has been poor in most places. Temperatures are likely to end up a little below average. As we move into September will the Atlantic cold pool keep the below average conditions going? I strongly favour that outcome as things stand. 

Please post your September CET predictions in this thread. The deadline for entries without incurring any penalty is 23:59 on Monday evening (31st). However, entries will be accepted up to 23:59 on 2 September (Wednesday).

September historic data summary
Here is the usual rundown of historic data for previous years.

Apart from 2012 we have not seen a cool September since 1994. There have been plenty of very warm Septembers. 2012 saw a CET of 13.0C and 1994 was 12.7C. Between 1998 and 2006 the CET was 14.3C or above in all years apart from one.

Long run averages:
1971-2000: 13.7C
1981-2010: 14.0C
1995-2014: 14.4C

Here is a chart of the September CET since 1961 with a 10 year moving average

Current model output

The current model output suggests the whole of the first part of August could be fairly close to average overall. Contingency planners forecast is very interesting though and I would agree entirely with what is said.

GEFS
http://www.wetterzentrale.de/pics/MT8_London_ens.png
http://www.wetterzentrale.de/pics/MT2_London_ens.png
http://www.wetterzentrale.de/pics/MT2_Manchester_ens.png
http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

Coolish start but returning close to average.

Met Office Contingency planners forecast
http://www.metoffice.gov.uk/media/pdf/0/a/A3_plots-temp-SON.pdf
Suggests an equally likely probability of cool or warm temperatures. No strong signal at all for September. A significant El Nino event often points to a warm September but the cool Atlantic SST's means that if winds come regularly from that direction the SSTs are likely to temper the normally warmer maritime conditions.

ECM - De Bilt
http://www.knmi.nl/exp/pluim/kansverwachtingen_staafdiagram.php?run=00&type=tx
http://www.knmi.nl/exp/pluim/kansverwachtingen_staafdiagram.php?run=00&type=tn

Very much on the cool side

Pattern matching (just for fun)
I had a quick look at the historic data with similar CET figures to the individual summer months from this year. Overall there is no obvious pattern to report. So nothing

September CET tracker
Here are the current prediction charts for the first part of September. Looking very chilly indeed I'm afraid. Well below the seasonal average. Maybe temperatures returning close to average by around the 9th but that is a long way off.

For myself I am going for 15.2c.  Thank you for the  Watch.…

14.1°c please.

14.15C please.

14.9 please.

13.9c please.

I'll go for 14.8 C, please. A cool start but warming up later, and a mostly dry, settled month I think.

Think I'll go for 12.9 - Coldest since 1994 - Thanks GW! 

One thing I have noticed in recent months is that Atlantic cold pool shifting eastwards. I expect it to have a strong influence during Autumn. A higher incidence of northerly and north-westerly winds then average. Cool SSTs will probably favour colder minima.

A cool but dry September - 12.8C

14.4c for me , thanks

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Gary

13.9c for me please.

I'll go for

13.8C

14.2 please

13.67C for me please 

13.7C for me please....