September 2023 C.E.T. and EWP forecast contests

[Roger J Smith]

I don't see an update for 27 Sep but assume we are now at 17.2 but close to 17.25, so today is unlikely to drop it past 17.15, Friday 29th around 17.0 and a drop on 30 Sep to 16.9 or very marginal 17.0, in either case warmer in two decimals than 2006 which got bumped up in v2.0.1.0 to 16.9 because of the rounding protocol change (16.85 now 16.9). In fact as far as I can determine, v2.0.1.0 is only about rounding up or down according to new protocols, all the changed values had been close to 5 as their second decimal, and v2.0.1.0 did not alter any daily means. So I imagine around NW we will take 16.9 as a tie but 2023 will probably be inserted into first place in tables. 

In that thread I have comparing legacy and v2.0 CET, I added a list of all months (and annual values in one dec) that saw changes to values; IIRC these only go back to 1947 and are very infrequent to about 1974 then become about as frequent as one change per year, some years got several and others none. Some went up 0.1 and some went down 0.1. 

On another question above, yes there is an adjustment made for urban effect, I thought it was 0.2, but whatever it is, we already see that in the numbers published daily, it is not worked into data sets later. The 0.2 is probably 0.6 for Rothamsted and zero for the other two. 

 

[Man With Beard]

23 hours ago, Roger J Smith said:

Posted during mid-month, 2023 can beat all but 2006 in first list, 17.0 would give an average of 16.625. We would tie 1826 and 1976 with a 16.9 result. For the may-Sep average, 17.0 brings us to 15.80, good for fifth. 

Rank ____ CET June-Sep_ Year __________ Rank ____ CET may-Sep_ Year

_01 __ ____ 17.175 ______ 2006 ____________ 01 ___ ___ 16.00 ______ 2006

_02t__ ____ 16.60 _______ 1826 ____________ 02 ___ ___ 15.90 ______ 1947

_02t__ ____ 16.60 _______ 1976 ____________ 03 ___ ___15.86 ______ 2022

_04 __ ____ 16.55 _______ 2022 ____________ 04 ___ ___ 15.82 ______ 2018

_05t__ ____ 16.50 _______ 1846 ____________ 05t___ ___ 15.68 ______ 1868

_05t__ ____ 16.50 _______ 1947 ____________ 05t___ ___ 15.68 ______ 1976

_07t__ ____ 16.475 ______ 1933 ____________ 07 ___ ___ 15.66 ______ 1846

_07t__ ____ 16.475 ______ 2003 ____________ 08 ___ ___ 15.62 ______ 1933

_09t__ ____ 16.45 _______ 1949 ____________ 09 ___ ___ 15.60 ______ 2016

_09t__ ____ 16.45 _______ 2018 ____________ 10 ___ ___ 15.58 ______ 2003

_11t__ ____ 16.35 _______ 1995 ____________ 11 ___ ___ 15.54 ______ 1911

_11t__ ____ 16.35 _______ 2016 ____________ 12 ___ ___ 15.52 ______ 1826

_13 __ ____ 16.325 ______ 2021 ____________ 13 ___ ___ 15.48 ______ 1959

_14t__ ____ 16.275 ______ 1779 ____________ 14 ___ ___ 15.44 ______ 1781

_14t__ ____ 16.275 ______ 1781 ____________ 15t___ ___ 15.40 ______ 1779,1780,1949,1995

________________________________

Note also that list of warm June and Sept combined missed 1846 (18.2, 14.7) which beats 2006 (15.8, 16.9) by .10 C on average. 

======================

Looking at current CET, the average in two decimals is now 17.35 rounded down apparently. (could be 17.33 or 17.34 based on differentials I saw last time I did a two decimal study). So it will take larger drops like days around 14 C to make running mean drop 0.1, and current output suggests 17.0 to 17.1 is now most likely end point. 

That's amazing Roger, thank you. 

Who on earth would have thought a near record June to September period could include such a dodgy 7 week period in July/August, potentially beating 1976 and 2018. 

Statistically, then, one could argue this was one of the best summers ever if September were considered a "bonus" summer month!

Edited September 28, 2023 by Man With Beard

[damianslaw]

2 hours ago, Man With Beard said:

That's amazing Roger, thank you. 

Who on earth would have thought a near record June to September period could include such a dodgy 7 week period in July/August, potentially beating 1976 and 2018. 

Statistically, then, one could argue this was one of the best summers ever if September were considered a "bonus" summer month!

An odd season, the anomalous warm periods coincided with the two calandar months of June and Sept, with a much more average period timed to coincide with two calandar months. Shift timings 2 weeks back and a different outcome altogether with a more balanced out effect, still the core summer period mid July to mid Aug would have been poor. Strange, in what feels are strange period since December. Indeed the last 3 years or so have brought persistant locked in patterns with little variation, the change in one to another very abrupt.  Don't seem to have the varied seasons with many changes anymore. The polar maritime/ switch to tropical  airstream seems defunct and back again notable by its absence. Euro heights have been very stubborn, ridges more robust, with deep troughs in atlantic adding a hold on patterns.

Edited September 28, 2023 by damianslaw

[Weather-history]

13 hours ago, Man With Beard said:

 

Statistically, then, one could argue this was one of the best summers ever if September were considered a "bonus" summer month!

This is where you have to take into account of rain days and sunshine levels and this is where June-September 2023 falls short. 

Temperatures are not enough to gauge how good a summer was.

[Metwatch]

On 16/09/2023 at 13:17, Summer Sun said:

19.1c to the 15th

5.6c above the 61 to 90 average
4.4c above the 81 to 10 average

Really is incredible thinking how warm the early part of this September was, completely smashed the first half of 1865, by pretty much a full degree. Now imagine we got an 1895 type spell at the end of this September, a month CET of 18C would be possible! Cc @Sun Chaser

Edited September 29, 2023 by Metwatch

[Addicks Fan 1981]

7 hours ago, Weather-history said:

This is where you have to take into account of rain days and sunshine levels and this is where June-September 2023 falls short. 

Temperatures are not enough to gauge how good a summer was.

According to the met office blog sunshine was 6% above average for the whole of the summer nationwide and rain was 11% above average too.   Very niño driven.    

[Metwatch]

Interesting table someone posted in a reply to a Met Office tweet, up to the 26th 2023 compared with others.

Edited September 29, 2023 by Metwatch

[The PIT]

Sunny Sheffield down to 16.7C +2.5C above average. Rainfall at 72.3mm 109.9% of the monthly average.

[Derecho]

Met office CET hasn't been updated. However judging by the obs at Stonyhurst, Pershore and Rothamstad, the CET on the 27th should come in as 15.3C with yesterday at 14.9C. 

Today should come in at 13.8C and tomorrow 13.1C, meaning it'll finish on 16.93C. Not sure if that is a record in absolute terms but it just shows how a fairly mild pattern will still dent the monthly CET as we move to the cooler part of the month.

I suspect October's CET is going to be a difficult one to call. A warm opening followed by some cooler air and a transient ridge into early next week. Warm air then coming back later next week but what happens after that is anyone's guess.

[Frigid]

Even if the CET comes in at 16.9C, it's still tied 1st place. 1st half of Sep 2023 with the second half of Sep 2011 would've resulted in a freakish CET for sure. 

[Derecho]

7 minutes ago, Frigid said:

Even if the CET comes in at 16.9C, it's still tied 1st place. 1st half of Sep 2023 with the second half of Sep 2011 would've resulted in a freakish CET for sure. 

It would have finished off at 17.12C. The notable warmth in 2011 only came after the 27th.

Comparing 2006 and 2023 by two decimal places, 2006 finished on 16.843 while 2023 is set to finish on 16.933 so a new record. Just for statistical purposes, it would have been cool to have both June and September reach 17C. Even in a warming climate it may be a while before we see it happen!

[Addicks Fan 1981]

2 hours ago, Derecho said:

It would have finished off at 17.12C. The notable warmth in 2011 only came after the 27th.

Comparing 2006 and 2023 by two decimal places, 2006 finished on 16.843 while 2023 is set to finish on 16.933 so a new record. Just for statistical purposes, it would have been cool to have both June and September reach 17C. Even in a warming climate it may be a while before we see it happen!

According to the CFS we could be in for a record breaking warm year, question is will this year match last year's overall CET or possibly be higher?    

[SqueakheartLW]

9 minutes ago, Addicks Fan 1981 said:

According to the CFS we could be in for a record breaking warm year, question is will this year match last year's overall CET or possibly be higher?    

Based on the data so far this year for rolling CET mean we are not that far behind 2022 and have been closing the gap to last year back down during September after we fell further behind 2022 during July and August. We were trending ahead of 2022 at the end of June after that warm June.

Below is the September rolling annual CET mean vs the eventual top 10 years

As can be seen here we are currently rated 2nd with only 2022 warmer at this stage (26th September). If we go on to have a mild October and November with anomalies at least 2C above average then we have a shot at beating last year's annual CET mean of 11.15C as it would only take an average December to beat the record as December 2022 has a low bar to beat.

[Metwatch]

30 minutes ago, Addicks Fan 1981 said:

According to the CFS we could be in for a record breaking warm year, question is will this year match last year's overall CET or possibly be higher?    

Squeakheart showed a more indepth data view of it all just above, but if September this year is to finish at 16.9C then the yearly CET of the first 9 months would be at 11.81C.

The first 9 months of 2022 the CET was at 12.01C calculated from all the the CET monthly means which are to one decimal place.

So I think there is a chance we could end up breaking last year's record, but it will depend if October and November is as mild as last year, and if December will be much milder than last year's one. I don't think many are going to agree if the Met Office confirm that we had the 2nd warmest year on record, and especially so if it ends up as THE warmest on record.

 

Edited September 29, 2023 by Metwatch

[Addicks Fan 1981]

24 minutes ago, Metwatch said:

Squeakheart showed a more indepth data view of it all just above, but if September this year is to finish at 16.9C then the yearly CET of the first 9 months would be at 11.81C.

The first 9 months of 2022 the CET was at 12.01C calculated from all the the CET monthly means which are to one decimal place.

So I think there is a chance we could end up breaking last year's record, but it will depend if October and November is as mild as last year, and if December will be much milder than last year's one. I don't think many are going to agree if the Met Office confirm that we had the 2nd warmest year on record, and especially so if it ends up as THE warmest on record.

 

The el niño phenomenon is definitely felt this year along with the warm Atlantic, also we have a positive IOD currently too.   

[Sun Chaser]

7 hours ago, Metwatch said:

Really is incredible thinking how warm the early part of this September was, completely smashed the first half of 1865, by pretty much a full degree. Now imagine we got an 1895 type spell at the end of this September, a month CET of 18C would be possible! Cc @Sun Chaser

5.6 degrees above the 61-90 average halfway through the month is absolutely something else. Really came out of nowhere

[Roger J Smith]

Confirmed CET and EWP ranks

Table needed no adjustments 2 Oct as 17.0 and 91 mm. For the purposes of "best combined" CET ranks are not adjusted down as is usually done, figuring that internal scoring for accuracy points will cancel out at least first day late penalty (and only one forecast was late by one day, two more by two days, both near top of ranks) as shown by order of entry in brackets. EWP scoring is already adjusted for late penalties. Top 30 best combined are noted.

Rank _ CET _ EWP _ Forecaster (order of entry) ____ EWP rank _____ best combined ranks (based on lowest total ranks)

_01 _ 17.1 _ 25.0 __ sunny_vale (15) _________________ 54 ____ 55 ___ 24th best combined 

_02 _ 17.1 _ 20.0 __ Earthshine (45, 2.5) _____________ 55 ____ 57 ___t-26th best combined

_03 _ 17.2 _ 47.0 __ R J Bingham (L2-1) _______________46 ____ 49 ___t-19th best combined 

_04 _ 16.7 _ 50.0 __ Midlands Ice Age (L2-2) _________ 38 ____ 42 ___ 12th best combined 

_05 _ 16.6 _ 49.0 __ Mazelike (50) ____________________42 ____ 47 ____t-16th best combined  

_06 _ 16.2 _ 58.4 __ Roger J Smith (24) _______________23 ____ 29 ___ 2nd best combined  

_07 _ 16.2 _ 45.0 __ Methuselah (42) _________________47 ____ 54 ___23rd best combined 

_08 _ 16.1 _ 50.0 __ Don (43) _________________________36 ____ 44 ___14th best combined 

_09 _ 16.1 _ 56.0 __ daniel* (48) ______________________28 ____ 37 ___ t-9th best combined 

_10 _ 16.0 _ 56.0 __ baddie (18) _______________________27 ____ 37 ___ t-9th best combined 

_11 _ 16.0 _ --- --- __ Kentish Man (37) ________________ --- 

_12 _ 16.0 _ 60.0 __ DR(S)NO (53, 28.5) _______________20 ____ 32 ___ t-4th best combined 

_13 _ 15.9 _ 59.0 __ shillitocettwo ( 7 ) ________________21 ____ 34 ___ 7th best combined 

_14 _ 15.9 _ 58.0 __ SteveB (17) ______________________ 24 ____ 38 ___11th best combined 

_15 _ 15.9 _ 62.0 __ snowray (41, 33.5) _______________15 ____ 30 ___ 3rd best combined 

_16 _ 15.9 _ 46.1 __ prolongedSnowLover (50) _______45 ____ 61 ___ 30th best combined  

_17 _ 15.9 _ 53.0 __ Wold Topper (51) ________________32 ____ 49 ___t-19th best combined 

_18 _ 15.8 _ 50.0 __ The PIT (19) ______________________34 ____ 52 ___ 22nd best combined  

_19 _ 15.8 _ 85.0 __ Summer Shower (20) ____________ 3 _____ 22 ___ best combined 

_20 _ 15.8 _ 40.0 __ syed2878 (31) ___________________53

_21 _ 15.8 _ 43.0 __ Metwatch (46) ___________________49

_22 _ 15.8 _ --- --- __ Summer Sun (32) ________________---

_23 _ 15.8 _ 42.0 __ noname_weather (56) ___________ 51 

_24 _ 15.7 _ 44.0 __ Feb1991Blizzard (38) ____________ 48

_25 _ 15.7 _ 68.0 __ February1978 (54) _______________10 ____ 35 ___ 8th best combined 

_26 _ 15.6 _ 76.0 __ Coventry Weather (10) ___________ 6 ____ 32 ___ t-4th best combined 

_27 _ 15.6 _ 61.0 __ Reef (26) _________________________16 ____ 43 ___13th best combined

_28 _ 15.6 _ 60.0 __ Leo97t (39, 6.5) __________________19 ____ 47 ___t-16th best combined  

_29 _ 15.6 _ --- --- __ Mark Bayley (57) ________________ --- 

_30 _ 15.5 _ 48.0 __ Plymsunshine (11) _______________43 

_31 _ 15.5 _ 87.0 __ Emmett Garland (14) _____________ 2 ____ 33 ___ 6th best combined  

_32 _ 15.5 _ 50.0 __ Stationary Front (27) _____________35 ____   

_33 _ 15.5 _ 66.0 __ Godber 1 (58) ____________________13 ____ 46 ___t-15th best combined

(30) _ 15.5 _ 56.0 __ consensus _______________________(26)

_34 _ 15.4 _ 49.0 __ dancerwithwings (22) ___________ 39 ____ 

_35 _ 15.4 _ 66.0 __ Mr Maunder (29) ________________12 ____ 47 ___ t-16th best combined

_36 _ 15.4 _ 59.0 __ seaside60 (33) ___________________22 ____ 58 ___ t-28th best combined 

_37 _ 15.4 _ 64.0__ I Remember Atlantic252 (40) ____ 14 _____ 51 ___ 21st best combined

_38 _ 15.4 _ --- --- __Damianslaw (53) ________________ ---

_39 _ 15.3 _ 41.0 __ catbrainz ( 2 ) ___________________ 52

_40 _ 15.3 _ 58.0 __ davehsug (47) ___________________25

_41 _ 15.2 _ 42.0 __ Frigid (34) _______________________ 50

_42 _ 15.1_ --- --- __ Walsall Wood Snow (36) _________---

_43 _ 15.0 _ 56.0 __ Weather26 ( 3 ) __________________26

_44 _ 15.0 _ 55.0 __ Mulzy (45) _______________________31

_45 _ 15.0 _ 50.0 __ Moorlander (55) ________________ 37

_46 _ 14.9 _ 49.0 __ Jonboy (28) ______________________40

_47 _ 14.8 _ 49.0 __ rwtwm (30) ______________________41 

_48 _ 14.8 _ 72.0 __ Weather Observer (35) __________ 8 ____ 56 ___ 25th best combined 

_49 _ 14.7 _ 60.0 __ somerset girl ( 5 ) _______________ 17

_50 _ 14.7 _ --- --- __ Typhoon John ( 8.) ______________ --- 

_51 _ 14.7 _ 70.0 __ J 10 (L1-1) ________________________11 

_52 _ 14.6 _ 60.0 __ B87 (9) ___________________________18

_53 _ 14.5 _ 78.5 __ Bobd29 ( 6 ) ______________________ 5 ____ 58 ___ t-28th best combined 

_54 _ 14.5 _ 52.0 __ Addicks Fan 1981 (12) ___________ 33

_55 _ 14.5 _ 85.0 __ JeffC (16) __________________________3 ____ 58 ___ t-28th best combined 

(56) _ 14.3 _ 75.9 __ 1993-2022 average ______________6.1

_56 _ 14.2 _ 92.0 __ Summer18 (13) ___________________ 1 ____ 57 ___ t-26th best combined 

(56) _ 14.2 _ 76.0 __ 1991-2020 average _______________ 6

_57 _ 14.1 _ 55.0 __ NeilN (23) ________________________ 30 

(58) _ 14.0 _ 77.2 __ 1981-2010 average _______________5.5

_58 _ 13.9 _ 47.0 __ Polar Gael ( 1 ) ____________________44

_59 _ 13.9 _ 74.0 __ summer blizzard (25) _____________ 7

_60 _ 13.8 _ 55.0 __ chilly milly ( 4 ) ____________________29

_61 _ 13.5 _ 71.0 __ virtualsphere (21) _________________ 9

(62) _ 13.4 _ 80.9 __ average of all data (CET 1659-2022 EWP 1766-2022) __ 4.6

_ 58 on time CET forecasts, and one 1d late, also two 2d late, total 61 _ consensus (median) 15.5 _ 

<<< Scoring is not official until fully adjusted and confirmed by J 10. >>>

==========================

EWP Forecasts in order

 92_sum18 .. 87_EG .. 85_Jeff, SumSh ..  80.9_all data ..78.5_bobd ..

 77.2_81-10 ... 76.0_91-20 ...76_CovW .. 75.9_93-22 ... 74_sb .. 72_WxObs ... 71_virt .. 70_J 10^ ..

 68_Feb78 .. 66_MrM, godb .. 64_IRem .. 62_snow .. 61_Reef .. 60_som g, B87, leo, DR(S) ..

 59_shil, sea .. 58.4_RJS .. 58_Ste, dave .. 56_wx26, bad, dan* ...  55_cm, NN, Mul ... 53_WT ..

 52_Add .. 50_PIT, SF, Don, moor, MIA^^.. 49_dww, jon, rwtwm, maze .. 48_plym ..  47_PG,RJB^^ ...

 46.1_pSL .. 45_Meth .. 44_Feb91 ... 43_Met .. 42_Frig, non ... 41_cat ... 40_syed .. 25_sv .. 20_Earth

- - - - -

55 EWP forecasts (2 x 2d late, 1 at 1d late) ^ late day(s) _ consensus 56.0 

{= = = = = = = = = = = = = = = = = = = [] [] [] [] = = = = = = = = = = = = = = = = = =}

Edited October 2, 2023 by Roger J Smith

[sunny_vale]

On 24/08/2023 at 21:37, sunny_vale said:

17.1C and 25mm why not!

Do you get bonus points if you predict a record . . . 

[SqueakheartLW]

1 hour ago, sunny_vale said:

Do you get bonus points if you predict a record . . . 

LOL

Looking like sunny_vale won't be that far out for the CET. The precipitation guess looks like it won't be anywhere close.

As for bonus points that is a good idea that should be tried out. Only as long as the bonus points are awarded if:

1. Firstly a record must be set. If you predicted a record warm or cold month you get a point.
2. If this happens then an extra bonus point if you guessed the exact CET value to 1 decimal place

Worth those who run these monthly CET and precipitation competitions trying this out.

[Derecho]

1 hour ago, sunny_vale said:

Do you get bonus points if you predict a record . . . 

I remember back in December 2015, someone predicted a CET of 10.0C and nobody thought it would happen. Turned out to be an accurate guess! Should have had bonus points.

Yesterday I think will have come back with a CET of 14.2C, a little higher then the GFS was predicting so we need a CET of 13.2C or above today to get a 17.0C September CET. 

[BlueSkies_do_I_see]

2 minutes ago, Derecho said:

I remember back in December 2015, someone predicted a CET of 10.0C and nobody thought it would happen. Turned out to be an accurate guess! Should have had bonus points.

Yesterday I think will have come back with a CET of 14.2C, a little higher then the GFS was predicting so we need a CET of 13.2C or above today to get a 17.0C September CET. 

Given wide parts of the country are at around 15C at midnight, it's going to happen.

[The PIT]

Sunny Sheffield still at 16.7C +2.6C above average. Rainfall unchanged.

Looks like we will finish on 16.6C beating the previous record of 16.3C recorded in 2001.

[Summer8906]

On 26/09/2023 at 07:31, Weather-history said:

I think the summer maybe remembered for one of those that go belly-up after June. 

Indeed, I suspect it will join 1957 and 1992 as a go-to example when people make the point when a good June doesn't necessarily mean a good summer.

[Derecho]

40 minutes ago, BlueSkies_do_I_see said:

Given wide parts of the country are at around 15C at midnight, it's going to happen.

Seems likely, only Rothamstad got into single figures this morning as well so the GFS from a few days ago went too low.

[richie3846]

1 hour ago, The PIT said:

Sunny Sheffield still at 16.7C +2.6C above average. Rainfall unchanged.

Looks like we will finish on 16.6C beating the previous record of 16.3C recorded in 2001.

How far back do your records go?