Please send your predictions to me via Private Message this month and do not post directly into the thread. This is to avoid tactical predictions as we approach the end of this year's competition.

So far this year we have had 10 months significantly above average and one significantly below. Not a single month close to average. Will the warm trend continue through December or can we expect a first taste of winter at some point? Very difficult to say at the moment. One thing is for sure. The 850 temperatures will dip back to close to average from 2 December. But these are not necessarily a good predictor of surface temperatures at this time of year.

The record CET year is still very much on track. Indeed an 11C year is still a possibility. As at the end of November the CET for the year as a whole will comfortably be the warmest on record - ahead of 1995 which currently holds the record.

If the November CET finishes at 8.3C we need a December CET of 4.5C to beat the current CET record and 6.0C to finish at 11C.

The deadline for entries without incurring any penalty is 23:59 on Sunday evening (30th). However, entries will be accepted up to 23:59 on 2 December (Tuesday evening).

December historic data summary

Here is the usual rundown of historic data for previous years. December is the only month where the 1981-2010 mean is lower than the 1971-2000 mean and quite a bit lower too.

A real mixed bag of Decembers in recent years. Several very cold years - in particular 2008 (3.5C), 2009 (3.1C) and 2010 (-0.7C). Also some very warm years 2006 (6.5C), 2011 (6.0C) and 2013 (6.4C). In between there have been a few average years as well.

Long run averages:
1971-2000: 5.1C
1981-2010: 4.6C
1994-2013: 4.5C

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

Here are some details of what the models and forecasters generally are saying at the moment.

GEFS (850 and 2m temps)
http://www.wetterzentrale.de/pics/MT8_London_ens.png
http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png
http://www.wetterzentrale.de/pics/MT2_Manchester_ens.png
http://www.wetterzentrale.de/pics/MT2_London_ens.png
850 temps are close to average but the surface temperatures look to be generally slightly above average based on these charts

ECM(De Bilt) maximum and minimum temps
http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php
http://www.knmi.nl/exp/pluim/kansverwachtingen_staafdiagram.php?run=00&type=tn
http://www.knmi.nl/exp/pluim/kansverwachtingen_staafdiagram.php?run=00&type=tx
Looking fairly close to average for De Bilt.

Met office
http://www.metoffice.gov.uk/public/weather/forecast
The narrative suggests that temperatures could be somewhat chilly at times in the first 10 days but then recovering close to average.

Pattern matching (just for fun)
Looking back at last month I concluded with this comment which was pretty close to what actually happened.

"on balance I would be inclined to go for another significantly above average month in November."  

So lets look ahead to December.

2014 will have the third warmest Autumn on record with a CET close to 12C exactly. The only warmer years were 2011 (12.43C) and 2006 (12.63C). In each of those two years December was also well above average with a CET of at least 6C.

However on the flip side we have had a couple of years in recent times with a very warm Autumn (including November) followed by a cold December. 1978 saw an Autumn CET of 11.53C (with November CET of 8.5C) followed by a December CET of 3.9C. 2009 saw an Autumn CET of 11.5C (with November CET of 8.7C) followed by a December CET of 3.1C.

If we look at the CET figures for the first 11 days of December in each of the above 4 years we see that December 2006 started off very warm whereas 2011 was close to average at 5.4C (exactly what the models are currently predicting for this year - see below). 2009 was above average in the first 11 days at 6.3C. 1978 was slightly below average at 5.1C although it started very cold and turned milder for a time after the first week.

Of the four years I would say that 2011 is the closest match based on the current output for early December. But what happens in the second half of the month is anyone's guess at this point. On balance I would favour an above average month overall but not by a great deal. Somewhere between 5.5C and 6C maybe. But if we do get a cold spell towards the end of the month we could end up much colder than this.

Latest forecast December CET tracker

Overall the first 11 days of December currently looking like being very close to average.

Mine is in... Many thanks for doing this.

Just sent mine in. This will be a tough one as December could go almost anywhere from very mild to quite cold I reckon.

It's getting a bit like a sporting contest this year. 4.5C to beat the annual CET, 6.0C to exceed 11C. It's like the final grand prix this year, or the last event of a decathlon. There's a clear front-runner, they only need to avoid cocking up the final event to secure the title, but there is always the risk they could do just that and hand it to their rival. Same kind of tension. Which is why I don't get those who are wishing for cold weather just now. Wait! You can have as much snow and ice in January and February as you like, but please let's see 2014 smash the record. Ideally let's have it exceed 6C and give us an 11C year.

If only August had been even average, it would be all over by now.

Cheers for all your hard work on this GW, will PM my guess in a moment, cheers again!

Just put in the raw values from the first 11 days of the GFSP 00z op run and got a CET anomaly south of -1.5*C.

Such is the winter-time impact of large ridges of high pressure across the UK positioned far enough north to keep us clear of a mild SW flow.

The ECM 00z op run looks a little colder still. This is the reason why just looking at CET records can give false impressions when trying to establish what produces a cold winter that actually delivers a good amount of snow. I remember December 2005 featured a lot of high pressure, often with fog that was on a few occasions freezing. The only white precipitation was some sporadic powder snow IIRC.

My thoughts as well! Lets hope we smash the cet record and if we get an 11c+ cet 2014 imo will be the most memorable year weather wise

in my lifetime. Ive a feeling though the weather is going to do a `Liverpool` and slip up at the very end

We are definitely in with a chance of the first below average month since August and only the second of the year. After an above average first couple of days of December the next 11 look below average at the moment. Not by much it has to be said but consistently by a degree of so.

One peculiar quirk, no December with a CET of 5.9C yet two with 8.1C

Just looked around this morning . Some figures until later today.

Taken at  07:53

Metcheck        6.63c.  Anomaly 1.29c.

N-W               7.29c.  Anomaly 2.2c.

Mount Sorrel   7.03c.  Anomaly 1.93c.

My Mean         6.5c.    Anomaly 0.0c.   My figure is last Decembers CET for my  station..     

The Normal Run Of Figures......

Met Office Hadley       6.2c.      Anomaly      1.3c.   Provisional to  1st.

Metcheck                   6.60c.    Anomaly      1.61c.

N-W                          7.29c.    Anomaly       2.2c.

Mount  Sorrel             6.98c.    Anomaly       1.88c.

My   Mean                  6.5c.      Anomaly       0.0c.

Thanks for all your kind words and comments. This year seems to have flown by.

So here is the final table of predictions for 2014. A slight majority going for the warm theme of 2014 to continue through to the end of the year.

Good luck to everyone with their December predictions. A new competition will be up and running for 2015 in just 4 weeks time.

If its hovering around 4.10°c towards the end of the month, there will be two very nervous contestants

Sub 4c Steve wins...greater than 4c Darren wins. 

Its been a great year. 

No offence to Darren, but I hope you are closer!

In fact, I'd be happy if Stormchaser or Surrey John won the month (and I guess you would, too) 

Met Office Hadley     6.4c.       Anomaly      1.4c.   Provisional to 2nd.

Metcheck                 5.50c.     Anomaly      0.51c.

N-W                        6.76c.     Anomaly      1.67c.

Mount  Sorrel           5.92c.     Anomaly      0.82c.

My   Mean                5.9c.       Anomaly      0.6c.

Cheers Saint

I can't believe so many people here have overlooked the 'Big freeze of December 2014' that is looming and will start presenting itself in the models in a week or so !

I'm glad Stormchaser is seeing it.

Are you teasing again Gusty 

me Jonesy ? ...never !

(Clears throat).  Yes Steve.  We came up with the same prediction independently in November but I see you've gone for a "winning score" in December.  We are 3c apart as I'm at the milder end.

GFS is now showing colder nights during the next 5 days than was the case back on 30th November, with the mean temperature for 4th-9th now predicted to be about 1*C lower (near to 3.5*C on the 12z op run).

After that, the outlook is fairly similar temperature-wise to the runs of 30th November (reflects the lack of interesting changes in lower-res!), with a milder theme due to the flat westerlies still being shown until late in the run, which leaves the CET estimate just below 5*C to 19th December.

Other models point towards the jet tracking further south beyond the 9th which would keep temperatures lower, which threatens to derail the record CET attempt right at the final hurdle 

I must add, I'm amazed the Hadley CET estimate is all the way up at 6.4*C. I know it's early in the month, but my mean is at 4.9*C and as far as I have seen, conditions across England have been similar to here in the areas under cloud, while colder nights have offset warmer days where the skies have been clear.

Not that it matters too much - the impact on the CET estimate to the 19th is not much over 0.1*C  

Met Office Hadley       5.5c.       Anomaly     0.4c.  Provisional  to  3rd.

Metcheck                   5.06c.     Anomaly     0.07c.

N-W                          5.82c.     Anomaly     0.73c.

Mount  Sorrel             5.25c.     Anomaly     0.15c.

My    Mean                 5.25.       Anomaly    - 1.6c. 

Here 2.6c

Mean min -0.5c

Mean max 5.8c