December 2014 CET forecasts (start of 2014/15 contest year)

[Lettucing Gutted]

So even at the halfway point it will still be up in the air whether December 2014 finishes as a cold month, average month or a mild month which will single handedly determine if 2014 becomes the warmest year on record.  Still this situation is quite different from most months this year (apart from August) in that the halfway point question had been not if but how mild the month will finish.

Edited December 8, 2014 by Craig Evans

[J10]

Might be worthy of analysis. See if there is any correlation between the date of the CET estimate and the accuracy...

 

Your wish is my command, admittedly 2 week late, but never mind.

 

 I have done some analysis and here are the findings.

 

2013-2014 Data Analysis.pdf Edit  I have changed the download a bit - to improve formatting and alignment of the  correlation figures

 

2013-2014 Data Analysis.xls

 

In terms of correlation between prediction time and Monthly ranking. There is a -0.17 correlation, which means the later the entry more likely is to be correct, however over the year this relationship is not particularly strong.

 

However for 4 months, this was a stronger correlation than -0.35 these being January February, April and August. This is probably due to strong indications of the the likely temperature appearing in the last few days of the preceding month. Other month saw a figure closer to 0, with Dec 13 and July 14 being marginally positive, indicating earlier entries being higher ranked than later entries. The reasons for this might be that the indications towards the end of the month might have been misleading or inconclusive.

 

Further to the above, I have also split the entries into 4 quartiles, with the first quartile being the first 1/4 entries etc, this makes allocations a bit arbitrary around the edges, e.g allocation is a bit tricky with 87 entries, but these figures are at least decent as indicative figures.

 

In addition these are the figures across the year, with later entries getting better ranking points (1= last, to 100 = 1st) across the year. Again this hides a variation.

 

50.5 Overall       

42.5 1st Quartile       

50.8 2nd Quartile       

54.0 3rd Quartile      

54.7 4th Quartile

 

As an example, the 4th quartile for Jan,Feb and August each seeing the average 4th quartile score over 60. e.g. later entries dong far better than earlier entries.

 

Finally I have also analysis the entries compared to the actual outturn, and on average, there was a 0.8c under prediction. given such a mild year this is no surprise. The best predicted month was May 0.1c out in terms of average prediction to outturn, the Worst predicted month was August which was on average over predicted by 2.3c.

Edited December 8, 2014 by J10

[BornFromTheVoid]

Good stuff J10, interesting read. Certainly saved me a lot of work, I'd just done an analysis on the November CET guesses and found no correlation (though much more variability in the guesses further from the deadline).

[TonyH]

Your wish is my command, admittedly 2 week late, but never mind.

 

 I have done some analysis and here are the findings.

 

2013-2014 Data Analysis.pdf

 

2013-2014 Data Analysis.xls

 

In terms of correlation between prediction time and Monthly ranking. There is a -0.17 correlation, which means the later the entry more likely is to be correct, however over the year this relationship is not particularly strong.

 

However for 4 months, this was a stronger correlation than -0.35 these being January February, April and August. This is probably due to strong indications of the the likely temperature appearing in the last few days of the preceding month. Other month saw a figure closer to 0, with Dec 13 and July 14 being marginally positive, indicating earlier entries being higher ranked than later entries. The reasons for this might be that the indications towards the end of the month might have been misleading or inconclusive.

 

Further to the above, I have also split the entries into 4 quartiles, with the first quartile being the first 1/4 entries etc, this makes allocations a bit arbitrary around the edges, e.g allocation is a bit tricky with 87 entries, but these figures are at least decent as indicative figures.

 

In addition these are the figures across the year, with later entries getting better ranking points (1= last, to 100 = 1st) across the year. Again this hides a variation.

 

50.5 Overall       

42.5 1st Quartile       

50.8 2nd Quartile       

54.0 3rd Quartile      

54.7 4th Quartile

 

As an example, the 4th quartile for Jan,Feb and August each seeing the average 4th quartile score over 60. e.g. later entries dong far better than earlier entries.

 

Finally I have also analysis the entries compared to the actual outturn, and on average, there was a 0.8c under prediction. given such a mild year this is no surprise. The best predicted month was May 0.1c out in terms of average prediction to outturn, the Worst predicted month was August which was on average over predicted by 2.3c.

Great stuff Julian - quite the statistician 

[J10]

Great stuff Julian - quite the statistician 

 

Cheers

 

I have been called worse.

Edited December 8, 2014 by J10

[summer blizzard]

The minimum today is 0.8C while maxima look like reaching about 6C, so a drop to 4.5C is likely on tomorrows update.

 

After that, the 06z NetWx model (both SR and MR) has the CET at:

 

4.6C to the 9th (5.8]

4.8C to the 10th (6.5)

4.9C to the 11th (6.1)

4.9C to the 12th (4.7)

4.7C to the 13th (2.4)

4.6C to the 14th (2.8]

 

A fairly average next 7 days keeps us slightly below the 61-90 and 81-10 average by the 14th.

 

Good chance of a below average month provided that the second half is colder than the first then.

[Summer Sun]

4.5c to the 8th

 

-0.5c below the 61 to 90 average

[Summer Sun]

Up-to 4.8c to the 9th

 

-0.3c below the 61 to 90 average

[BornFromTheVoid]

Minimum today of 2.2C while maxima look like reaching about 8C, so remaining on 4.8C on tomorrows update.

 

After that, the 00z GFS parallel has the CET at:

4.9C to the 11th (5.7)

4.9C to the 12th (5.5)

4.7C to the 13th (2.0)

4.7C to the 14th (4.2)

4.9C to the 15th (7.8]

5.2C to the 16th (9.6)

 

So despite what feels like a cool start and some cool weather coming up, we will be almost bang on average by mid month.

 

If we are at 4.9C by the 15th, then if every day after was in the top 5% of the warmest days, the final CET would be 7.0C, while the coldest 5% would produce a CET of about 1.3C. It's extremely unlikely that the CET will end up above or below that range, which rules out Craig Evan's guess at the top end, and Roger J Smith's at the bottom end.

Doing the same, but for the top and bottom 25% we get a range of 5.7C to 3.0C. This would be the likely maximum and minimum range, and would make another 18 guesses quite unlikely to win.

[BlueSkies_do_I_see]

Calling lower than average CET for each month probably means you would lose the competition as a good proportion of months finish above average (without referring to the figures I would guess at about +80% of the CET months of the last 5 years finishing above average?). 

 

Calling somewhere around 0 to 1.5 above the CET average each month would most likely guarantee you a top 20 finish in the competition on a typical year.

Edited December 11, 2014 by BlueSkies_do_I_see

[TonyH]

Cant see it ending up below average now, even if we do keep seeing this Pm air much of the time, with all the wind and cloud associated limiting night frosts even though days are cool to average. Somewhere in the 5 to 6c range is my latest hunch (too late for my 4.0c guess )

[TonyH]

Calling lower than average CET for each month probably means you would lose the competition as a good proportion of months finish above average (without referring to the figures I would guess at about +80% of the CET months of the last 5 years finishing above average?). 

 

Calling somewhere around 0 to 1.5 above the CET average each month would most likely guarantee you a top 20 finish in the competition on a typical year.

That is my usual tactic but sometimes I get a feeling for a below average month as I did this time (probable mistake!).

[Summer Sun]

4.8c to the 10th

 

-0.2c below the 61 to 90 average

[The PIT]

Sunny Sheffield 4.8C just above normal. One day in double figures making a big dent upwards in it.

[Summer Sun]

4.8c to the 11th

 

-0.1c below the 61 to 90 average

[BornFromTheVoid]

Minimum today is 3.3C, while maxima look like being around 7C, so probably rising to 4.9C on tomorrows update.

 

After that, the 06z GFS parallel has the CET at:

4.7C to the 13th (2.8]

4.7C to the 14th (4.6)

4.7C to the 15th (4.8]

4.8C to the 16th (6.2)

5.0C to the 17th (9.1)

5.2C to the 18th (8.3)

5.2C to the 19th (5.6)

 

A relatively mild week coming up, taking the CET slightly above average after mid month. Warmest CET year on record is very much still on.

[summer blizzard]

Conflicted. On the one hand i want cold weather and do still think a CET near or below average stands a good chance (well done Netweather forecast range) but on the other this coming pattern puts me right into the fray.

[BlueSkies_do_I_see]

I think I am resigned to the fact my 4.5C prediction now is going to be at least 0.8C out barring something cold appearing in the charts for post Christmas!

Edited December 12, 2014 by BlueSkies_do_I_see

[Lettucing Gutted]

Conflicted. On the one hand i want cold weather and do still think a CET near or below average stands a good chance (well done Netweather forecast range) but on the other this coming pattern puts me right into the fray.

and so the broken record of the post June 2013 mild train carries on despite the best efforts of the very -OPI.

Edited December 13, 2014 by Craig Evans

[DAVID SNOW]

and so the broken record of the post June 2013 mild train carries on despite the best efforts of the very -OPI.

 

Looking that way Craig. My guess of 5.0 looking too low ATM.

[The PIT]

Sunny Sheffield 4.4c just below normal

[damianslaw]

CET mean not necessarily reflective of the UK as a whole, the northern half of the country comfortably below average this stage.

 

I wouldn't be too quick to call an above average December at this range, the upcoming milder week may be cancelled out by a rather cold final last 7 days.

[DAVID SNOW]

Above average is nailed now IMO. Cold end of year may bring the CET down  to      about 5 though.

[reef]

CET mean not necessarily reflective of the UK as a whole, the northern half of the country comfortably below average this stage.

 

I wouldn't be too quick to call an above average December at this range, the upcoming milder week may be cancelled out by a rather cold final last 7 days.

It has seemed 'cold', especially after last winter's horror show, but in reality it has actually been pretty close to average everywhere - even in the north:

 

http://www.met.rdg.ac.uk/~brugge/CURR.html

 

Here we're on 4.8C to the 13th, which is exactly the 1981-2010 average.

[Summer Sun]

Hadley has finally updated

 

4.8c to the 12th

 

-0.1c below the 61 to 90 average