With only a few hours left of October as we head to November I'm assuming some  people have already sent their inspired guesses to GW.

I simply post this here as a reminder, and hope that it will be superseded by GW's regular infographics and analysis at his earliest convenience. 

In fact, Gavin P. actually gave us quite a good reminder of that in one of his recent videos because he pointed out there, the fact that September's CET came out almost bang on the 1961-90 average, and that October is looking as though it will do likewise as well in the end. This means that what happens in November will determine whether this autumn's overall CET goes down as being warmer or colder than average according to that old 1961-60 average which is used on the Hadley website for that.

If you went by the more up to date 1981-2010 average though, this would probably show that we have had a slightly colder than average autumn so far according to the average overall CET figure. That has gone completely against the grain of what recent seasons have been like in recent years, and the fact that this has happened after such a hot summer, makes that all the more remarkable.

Im happy if this thread gets removed once the real deal is up and running !

As usual all CET predictions to be sent to me via PM please

Deadline is 2359 on Saturday evening (3 November).

A very average October overall meaning we have now had three average months in a row.

Historic CET summary for November

1971-2000 6.9C (30 years)

1981-2010 7.1C (30 years)

1998-2017 7.4C (last 20 years)

November has been a mixed bag in recent years. 2009, 2011, 2014 and 2015 were all very warm (8.6C and above). Whereas 2010, 2013 and 2016 were all cold (6.2C or below). 2010 and 2017 were close to average.

Here is a chart of the November CET for all years since 1961:

Direct link to larger version of the chart CHART

Current model output

GFS (12z) - currently favouring above average conditions after a cool start  

http://www.wetterzentrale.de/de/show_diagrams.php?model=gfs&var=2&geoid=49069&lid=ENS&bw=

GEM (12z) - similar to GFS

http://www.wetterzentrale.de/de/show_diagrams.php?model=gem&var=2&geoid=49069&lid=ENS&bw=

Multi Op - generally good agreement between the operational runs. Turning mild.

http://www.wetterzentrale.de/de/show_diagrams.php?model=multi&var=2&geoid=49069&lid=OP&bw=

Met Office contingency planners outlook 

No strong signal here. Probabilities slightly favour above average conditions but it is very marginal.

https://www.metoffice.gov.uk/binaries/content/assets/mohippo/pdf/public-sector/forecast-temp-ndj-v1.pdf

Temperature analogues

So I had a look at years since 1950 where the temperature for August, Sept and October were similar to this year - i.e. close to average. Criteria were no single month was more than 1C different to 2018 and the combined temperature difference over the three months was less than 2C. Some interesting years popped up in the analysis, eight in total. None had a January or February above average and there are some very cold months in the mix. There are a few Decembers that are above average but also a number of cold ones. November is interesting as generally the signal there is for mild or even very mild conditions with only one cold year out of the eight.

Based on the latest output (see below) the first half of November looks like being very mild after a cold start. There are hints that higher pressure and colder conditions might appear later in the month but my guess at this point is that will not be enough to prevent November from being a warm month overall. Potentially a CET above 8C is possible (maybe similar to 2009, 1953 or 2002). Even if we do get much colder conditions in the second half of the month I think it is unlikely the CET will finish worse than close to average again (i.e. like 2008 or 2000).

I added 1878 into the table just for fun as we have been very closely tracking the 1878 temperatures over the past three months. We will deviate from that in November I am fairly sure. A CET of 3.5C is just about impossible given the current output.

First look at November temperature tracker

After a cool start it turns very mild.

I've made this thread sticky. GW if you want to start a new thread to replace go ahead and I will sticky that instead.

Welll done Brian. I usually do the sticky for the CET competition. However, I've not been online quite so much since I broke my ankle 3 weeks ago.

Thanks to you both, and get well soon HT! Perhaps you could sticky the October CET thread again, at least until GW has had a chance to update with the final comp results? Thanks.

Thanks Brian. I'm happy to stick with this thread as it is.

Met Office Hadley            6.8c.      Anomaly      -2.3c  provisional to 1st.

Metcheck                         6.13c     Anomaly      -0.78c

Netweather                      7.61c     Anomaly      0.72c

Bordon                            3.4c       Anomaly     -6.76c

Canvey Island                  6.5c       Anomaly      -2.12c

Cheadle Hulme                 7.6c       Anomaly     -1.25c   

Clevedon Weather             6.8c       Anomaly     -2.36c

Darwen                            6.7c       Anomaly     -0.94c

Hexam                             3.4c       Anomaly     -2.9c

Mount Sorrel                     5.2c      Anomaly      -2.26c

Mansfield Weather  5.7c      Anomaly     -1.78c

Peasedown St John   5.9c     Anomaly     -1.84c

Treviskey Redruth               5.8c       Anomaly     -3.65c.

Mean of My watched 10 Stations    5.7c.    Anomaly    -2.57c      

Met Office Hadley         6.8c.     Anomaly     -2.3c. Provisional to 2nd.

Metcheck                      6.57c    Anomaly     -0.35c

Netweather                   6.53c    Anomaly     -0.38c

Clevedon Weather          7.7c     Anomaly      -1.46c 

Darwen                          8.3c    Anomaly      0.66c

Mansfield Weather           7.3c    Anomaly     -0.18c

Peasedown St John     5.67c   Anomaly    -2.07c.

Mean of my 10  watched stations    8.81c  Anomaly   0.46c.     

Latest output suggests we are, from today, going into a very warm period of weather. By mid month the CET will be more than 1.5C above average.

November CET predictions

Here are the predictions for November

The competition will go down to the wire as Darren S and Gusty have predicted essentially the same figure, 7.50C and 7.53C respectively.

Link to larger table TABLE

Thank you for the table GW. Printscreen button pressed.

Met Office Hadley         7.6c.   Anomaly     -1.2c. Provisional to 3rd.

Metcheck                      7.62c.  Anomaly    0.69c

Netweather                   7.72c   Anomaly    0.83c

Mansfield Weather      8.4c     Anomaly    0.72c

Peasedown St John  6.48c  Anomaly  -1.25c.

Mean of my 10   8.63c  Anomaly  0.36c.       

Thanks GW.

Wonder whether we'll get another "collapse" in the final week to ten days? 

Met Office Hadley        8.5c.      Anomaly      0.0c. Provisional to the 4th.

Metcheck                     7.98c     Anomaly      1.06c

Netweather                  8.38c     Anomaly      1.49c

Cheadle Hulme             9.3c       Anomaly      0.45c

Clevedon Weather         9.7c       Anomaly      0.54c

Darwen                        9.5c       Anomaly       1.86c

Mansfield Weather         8.5c      Anomaly        1.02c

Peasedown St John        7.02c    Anomaly       -0.72c

Mean of my 10     8.71c  Anomaly  0.44c.  

Crazy how close their two November estimates are, as well. Whatever happens, it's going to come down to December (and hopefully we get a repeat of the 2010 month)

Thanks GW. Down to the wire it is then ! 

Met Office Hadley         8.9c      Anomaly     0.6c. Provisional to 5th.

Metcheck                      8.50c    Anomaly     1.58c

Netweather                   8.8c      Anomaly     1.91c

Mansfield Weather         9.0c      Anomaly     1.52c

Peasedown st John      7.0c    Anomaly    -0.74c

Treviskey Redruth     10.5c    Anomaly  1.14c

Mean of my 10 stations   9.26c   Anomaly   0.99c.

My latest calculations have the CET reaching 9.7C tomorrow. After that the CET hovers around 9.5C to 9.7C right out to the 20th. No sign of any colder weather at this stage.

As always at this time of year the final 10 days of the month will be critical. If we keep the mild weather then a CET above 9C is quite possible. If it turns colder then the CET is likely to finish somewhere in the 8's.

The more settled 12z GFS brings a bit more variability to the CET but the same overall result; it just dips into the high 8s for 12th-13th but then climbs to the mid-9s for 17th-18th due to the long-draw S then SE flow, after which time a cooler E flow kicks in but a lot of cloud is simulated and as a result The CET doesn't decline much; still in the low 9s as of 21st.

While tropical cycles are hinting at a change of theme for the final third of the month, we do seem to yet again be looking at the CET being sat on a high pedestal prior to the topple. Assuming it comes around, that is!

Late today. No Internet... 

Met Office Hadley       9.3c.    Anomaly      1.2c.  Provisional to 6th

Metcheck                   9.16c     Anomaly      2.24c

Netweather                9.41c     Anomaly      2.52c

Mansfield Weather   9.6c     Anomaly   2.12c

Peasedown St John  7.66c   Anomaly   -0.08c

Mean of my 10 stations 9.73c  Anomaly   1.46c.