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

[DR(S)NO]

23 minutes ago, Don said:

Would be rather amusing if from now, the hot spell gets downgraded and we all look to have gone too high! 

Not that I'm expecting that mind.

Lol Don

I was thinking that as I watched all these changes in guesses. Like you, I’m not expecting that, however the second half of the month is still up for grabs so who knows.

[February1978]

I wonder if there's been a month where the collective mean forecast is so far above 'average'.....?!

Less settled in the second half, 15.7c and 68mm please.

[moorlander]

15c and 50mm please

[noname_weather]

15.8C and 42mm

[Mark Bayley]

15.6c please 

[Godber 1]

15.5c and 66mm please.

[damianslaw]

Most have gone very high, probably because it does look an exceptionally warm start. Good to know warmest first weeks to September on record as a comparable marker. 2021 was a very warm start.

September is a rapidly cooling month, once past the equinox the sun begins to lose alot of heat, notably high means by then tend to be attributable to southerly plumes or long fetch southwesterlies, as opposed to anticyclonic conditions, which in first half of Sept often bring warmest means especially when overhead or to our east. By late Sept high pressure can start to produce large diurnal ranges, with first frosts. 

 

Edited August 31, 2023 by damianslaw

[Wold Topper]

1 hour ago, Don said:

Would be rather amusing if from now, the hot spell gets downgraded and we all look to have gone too high! 

Not that I'm expecting that mind.

Thats why i don't get why some peeps are so eager to get their entries in early and are now scrambling to change it....

[Don]

Just now, Wold Topper said:

Thats why i don't get why some peeps are so eager to get their entries in early and are now scrambling to change it....

Yes, I always put my entry in on the evening of the final day of the month.

[Roger J Smith]

Table of forecasts for September 2023

CET _ EWP __ FORECASTER (order of entry) _____________ CET _ EWP _ FORECASTER (order of entry) ____

17.2 _ 47.0 __ R J Bingham (L2-1) ________________________

17.1 _ 25.0 __ sunny_vale (15) ___________________________ 15.3 _ 41.0 __ catbrainz ( 2 ) __________ 

17.1 _ 20.0 __ Earthshine (45, 2.5) _______________________15.3 _ 58.0 __ davehsug (47) __________

16.7 _ 50.0 __ Midlands Ice Age (L2-2) ___________________ 15.2 _ 42.0 __ Frigid (34) _______________

16.6 _ 49.0 __ Mazelike (50) _____________________________ 

16.2 _ 58.4 __ Roger J Smith (24) ________________________  

16.2 _ 45.0 __ Methuselah (42) __________________________ 15.1_ --- --- __ Walsall Wood Snow (36) _

16.1 _ 50.0 __ Don (43) __________________________________ 15.0 _ 56.0 __ Weather26 ( 3 ) __________

16.1 _ 56.0 __ daniel* (48) _______________________________15.0 _ 55.0 __ Mulzy (45) _______________ 

16.0 _ 56.0 __ baddie (18) _______________________________ 15.0 _ 50.0 __ Moorlander (55) 

16.0 _ --- --- __ Kentish Man (37) _________________________14.9 _ 49.0 __ Jonboy (28) ______________ 

16.0 _ 60.0 __ DR(S)NO (53, 28.5) ________________________14.8 _ 49.0 __ rwtwm (30) ______________ 

15.9 _ 59.0 __ shillitocettwo ( 7 ) _________________________14.8 _ 72.0 __ Weather Observer (35) __ 

15.9 _ 58.0 __ SteveB (17) ________________________________14.7 _ 60.0 __ somerset girl ( 5 ) __________

15.9 _ 62.0 __ snowray (41, 33.5) ________________________ 14.7 _ --- --- __ Typhoon John ( 8.) _________ 

15.9 _ 46.1 __ prolongedSnowLover (50) ________________ 14.7 _ 70.0 __ J 10 (L1-1) ___________________

15.9 _ 53.0 __ Wold Topper (51) _________________________ 14.6 _ 60.0 __ B87 (9) _____________________

15.8 _ 50.0 __ The PIT (19) _______________________________ 14.5 _ 78.5 __ Bobd29 ( 6 ) ________________ 

15.8 _ 85.0 __ Summer Shower (20) _____________________ 14.5 _ 52.0 __ Addicks Fan 1981 (12) _________

15.8 _ 40.0 __ syed2878 (31) _____________________________14.5 _ 85.0 __ JeffC (16) ______________________  

15.8 _ 43.0 __ Metwatch (46) _____________________________14.3 _ 75.9 __ 1993-2022 average ____________ 

15.8 _ --- --- __ Summer Sun (32) _________________________14.2 _ 92.0 __ Summer18 (13) ________________

15.8 _ 42.0 __ noname_weather (56) _____________________14.2 _ 76.0 __ 1991-2020 average ____________ 

15.7 _ 44.0 __ Feb1991Blizzard (38) ______________________14.1 _ 55.0 __ NeilN (23) ____________________

15.7 _ 68.0 __ February1978 (54) ________________________ 14.0 _ 77.2 __ 1981-2010 average __________

15.6 _ 76.0 __ Coventry Weather (10) ____________________13.9 _ 47.0 __ Polar Gael ( 1 ) _______________ 

15.6 _ 61.0 __ Reef (26) __________________________________ 13.9 _ 74.0 __ summer blizzard (25) ________

15.6 _ 60.0 __ Leo97t (39, 6.5) ___________________________ 13.8 _ 55.0 __ chilly milly ( 4 ) _______________

15.6 _ --- --- __ Mark Bayley (57) __________________________

15.5 _ 48.0 __ Plymsunshine (11) ________________________ 13.5 _ 71.0 __ virtualsphere (21) __________

15.5 _ 87.0 __ Emmett Garland (14) _____________________

15.5 _ 50.0 __ Stationary Front (27) _____________________

15.5 _ 66.0 __ Godber 1 (58) ____________________________

15.4 _ 49.0 __ dancerwithwings (22) ____________________

15.4 _ 66.0 __ Mr Maunder (29) ________________________ 

15.4 _ 59.0 __ seaside60 (33) ___________________________ 

15.4 _ 64.0__ I Remember Atlantic252 (40) _____________ 

15.4 _ --- --- __Damianslaw (53) _________________________

15.5 _ 55.0 __ consensus _______________________________ 13.4 _ 80.9 __ average of all data (CET 1659-2022 EWP 1766-2022)

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

<<< LATE FORECASTS are still accepted to end of 3rd of September and will be added to table.  >>>

(if order of entry contains two numbers, second is placement for EWP forecast in previous order before CET revised ... if EWP also revised just one order of entry appears)

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

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

 

 _ 52 on time forecasts and one 1d late (^), two 2d late^^ _ 55 total __ consensus (median) 55.0 mm

Edited September 12, 2023 by Roger J Smith

[Earthshine]

CET after the first week will surely rocket into the 18s

[Don]

14 hours ago, damianslaw said:

Most have gone very high, probably because it does look an exceptionally warm start. Good to know warmest first weeks to September on record as a comparable marker. 2021 was a very warm start.

September is a rapidly cooling month, once past the equinox the sun begins to lose alot of heat, notably high means by then tend to be attributable to southerly plumes or long fetch southwesterlies, as opposed to anticyclonic conditions, which in first half of Sept often bring warmest means especially when overhead or to our east. By late Sept high pressure can start to produce large diurnal ranges, with first frosts. 

 

This month is reminding me of September 2021 and that went on to have a CET of 16.0C  I fear that those rejoicing in a very warm September, but also want a cold snowy winter are likely be moaning a lot in a few months!

2 hours ago, Earthshine said:

CET after the first week will surely rocket into the 18s

September last year was in the 18's during the first week, too.

[LetItSnow!]

Rough estimate from me using model output shows a C.E.T. of about 19.4°C to the 10th, could be a touch higher or lower depending on variables. I would say somewhere between 18.5°C and 19.5°C.

[Roger J Smith]

Turns out we were discussing same data, warm starts to September, in last year's contest ... I will be posting usual running CET data in a few minutes and can say record values to 10 Sep were 18.2 in 1898, and after that 1865 was warmest for running means until 2006 took over around 21st. 

Actually I will just combine the two tables in one post. Some later editing may be needed. 

 

Warm Starts to September (from Sep 2022 thread)

Note: an updated table for warm CET values 10-20 Sep, 25 Sep and 30 Sep now posted on 3rd (p5) ...

Rank ___ Year ___ CET 1-7 ____ CET 1-30 (rank if top 20)

_ 01 ____ 1906 ____ 18.8 _____ 13.9

_ 02 ____ 1999 ____ 18.3 _____ 15.6 (t9)*

_ 03 ____ 1898 ____ 18.2 _____ 15.2 (t15) (1898 was 18.9 by 9th)

_ 04 ____ 2022 ____ 18.1 _____ 14.4

_ 05 ____ 2005 ____ 18.0 _____ 15.2 (t15)

_ 06 ____ 1795 ____ 17.9 _____ 16.0 (t6)

_t07 ____ 1868 ____ 17.8 _____ 14.3

_t07 ____ 1880 ____ 17.8 _____ 14.6

_t07 ____ 1973 ____ 17.8 _____ 14.3

_t07 ____ 1949 ____ 17.8 _____ 16.3 (t3)

_t07 ____ 1958 ____ 17.8 _____ 15.1 (t20)

_t12 ____ 1780 ____ 17.7 _____ 15.6 (t9)*

_t12 ____ 1824 ____ 17.7 _____ 13.7

_t12 ____ 1865 ____ 17.7 _____ 16.3 (t3)

_t15 ____ 1991 ____ 17.6 _____ 14.6

_t15 ____ 2006 ____ 17.6 _____ 16.8 (1)

* all ranks after 8th (1760) include at least one year (1760) with no daily data

(note 2021 was 17.2 and reached 18.0 by 11th, end of month 16.0 t6)

2016 was also 17.2 and finished 16.1 (5)

1895 was 16.0 and finished 15.4 (11)

1929 was 17.3 and finished 15.3 (t12)

========================================== o ==================================

 

Daily and cumulative normals for CET in September (1981-2010) with daily extremes 1772-2022

v2.0 CET is used for all data now (edited version) 

 

Date __ CET __ cum ____ max ____ min (records 1772-2022) ___ Extremes of daily running CET

 

01 ___ 15.4 __ 15.4 _____ 22.0 (1906) __ 7.1 (1816) __________  21.8 (1780,1906) _ 7.1 (1816)

02 ___ 15.3 __ 15.4 _____ 22.3 (1906) __ 7.6 (1816) ___________ 22.1 (1906) ______ 7.4 (1816)

03 ___ 15.3 __ 15.3 _____ 19.8 (1880) __ 8.2 (1816) ___________ 21.4 (1906) ______ 7.6 (1816)

04 ___ 14.6 __ 15.2 _____ 20.6 (2005) __ 7.7 (1841) ____________20.2 (1906) ______ 7.9 (1816)

05 ___ 15.1 __ 15.1 _____ 22.4 (1949) __ 8.1 (1841) ____________19.3 (1906) ______ 8.2 (1816)

06 ___ 15.0 __ 15.1 _____ 20.8 (1898) __ 8.5 (1841) ____________19.0 (1906) ______ 8.4 (1816)

07 ___ 14.9 __ 15.1 _____ 20.9 (1868) __ 8.1 (1952) ____________19.0 (1906) ______ 9.1 (1816)

08 ___ 14.9 __ 15.1 _____ 21.6* (1898) __8.8 (1931) ___________ 18.7 (1898,1906) __ 9.6 (1816)

09 ___ 14,7 __ 15,0 _____ 19.5 (1781,1898) _ 9.0 (1912) _______ 18.5 (1898) _____ 10.0 (1816)

10 ___ 14.7 __ 15.0 _____ 19.1 (1865,2011) __ 8.6 (1860) ______ 18.2 (1898) _____ 10.3 (1816)

 

11 ___ 14.8 __ 15.0 _____ 20.2 (1999) __ 8.2 (1860) _____________ 18.1 (1865,1898) _ 10.4 (1816)

12 ___ 14.4 __ 14.9 _____ 20.3 (1945) __ 8.1 (1848) _____________ 18.2 (1865) _____ 10.6 (1816)

13 ___ 13.9 __ 14.8 _____ 20.7 (2016) __ 6.7 (1807) _____________ 18.2 (1865) _____ 10.8 (1816)

14 ___ 13.7 __ 14.8 _____ 21.3 (2016) __ 6.7 (1807) _____________ 18.1 (1865) _____ 10.9 (1931)

15 ___ 13.6 __ 14.7 _____ 20.1 (2020) __ 7.8 (1986) _____________ 18.1 (1865) _____ 10.8 (1807)

16 ___ 13.7 __ 14.6 _____ 19.6 (1961) __ 8.1 (1807,1903) ________ 18.2 (1865) _____ 10.6 (1807)

17 ___ 13.8 __ 14.6 _____ 20.1 (1898) __ 8.1 (1807) ______________ 18.1 (1865) _____ 10.5 (1807)

18 ___ 13.9 __ 14.5 _____ 19.8 (1926) __ 6.9 (1807) ______________ 17.9 (1865) _____ 10.3 (1807)

19 ___ 13.6 __ 14,5 _____ 20.9 (1926) __ 7.3 (1952) ______________ 17.8 (1865) _____ 10.2 (1807)

20 ___ 14.0 __ 14.5 _____ 18.4 (1947) __ 6.9 (1919) ______________ 17.8 (1865) _____ 10.1 (1807)

 

21 ___ 13.6 __ 14.4 _____ 21.4 (2006) __ 6.7 (1836,1872) ________ 17.5 (1865) _____ 10.1 (1807)

22 ___ 13.8 __ 14.4 _____ 18.7 (1956) __ 6.6 (1872) ______________ 17.2 (1865) _____ 10.2 (1807)

23 ___ 13.5 __ 14.4 _____ 18.3 (1956) __ 6.0 (1773) _____________ 17.1 (1865,2006) _10.3 (1807)

24 ___ 12.8 __ 14.3 _____ 18.5 (1895) __ 6.9 (1872) ______________ 17.1 (2006) _____ 10.4 (1807)

25 ___ 12.7 __ 14.2 _____ 19.2 (1895) __ 7.4 (1812) ______________ 17.1 (2006) _____ 10.4 (1807)

26 ___ 12.8 __ 14.2 _____ 18.4 (1895) __ 6.0 (1885) ______________ 17.1 (2006) _____ 10.4 (1807)

27 ___ 12.9 __ 14.1 _____ 19.7 (1895) __ 6.0 (1885) _______________17.0 (2006) _____ 10.5 (1807)

28 ___ 13.2 __ 14.1 _____ 18.9 (2011) __ 4.9 (1824) ______________ 17.0 (2006) _____ 10.5 (1807)

29 ___ 13.0 __ 14.1 _____ 19.7 (2011) __ 5.6 (1918) ______________ 17.0 (2006) _____ 10.5 (1807)

30 ___ 12.8 __ 14.0 _____ 20.0 (2011) __ 6.3 (1808) ______________ 16.9 (2006) _____ 10.5 (1807)

* legacy record was 21.4 (2021) which remains the v2.0 value but 1898 was adjusted from 21.3 to 21.6

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

1991-2020 CET daily and cumulative values

01 ___ 15.2 __ 15.2 __________ 11 ___ 14.9 __ 15.1 __________ 21 ___ 14.0 __ 14.6 __________

02 ___ 15.5 __ 15.3 __________ 12 ___ 14.6 __ 15.1 __________ 22 ___ 13.8 __ 14.5 __________

03 ___ 15.5 __ 15.4 __________ 13 ___ 14.2 __ 15.0 __________ 23 ___ 13.5 __ 14.5 __________

04 ___ 15.2 __ 15.4 __________ 14 ___ 14.1 __ 14.9 __________ 24 ___ 13.0 __ 14.4 __________

05 ___ 15.4 __ 15.4 __________ 15 ___ 14.0 __ 14.9 __________ 25 ___ 12.9 __ 14.4 __________

06 ___ 15.1 __ 15.3 __________ 16 ___ 13.8 __ 14.8 __________ 26 ___ 13.1 __ 14.3 __________

07 ___ 14.9 __ 15.3 __________ 17 ___ 13.5 __ 14.7 __________ 27 ___ 13.2 __ 14.3 __________

08 ___ 14.8 __ 15.2 __________ 18 ___ 13.6 __ 14.7 __________ 28 ___ 13.5 __ 14.2 __________

09 ___ 14.8 __ 15.2 __________ 19 ___ 13.8 __ 14.6 __________ 29 ___ 13.5 __ 14.2 __________

10 ___ 14.7 __ 15.1 __________ 20 ___ 14.3 __ 14.6 __________ 30 ___ 13.1 __ 14.2 __________

 

Edited September 25, 2023 by Roger J Smith

[Don]

4 hours ago, LetItSnow! said:

Rough estimate from me using model output shows a C.E.T. of about 19.4°C to the 10th, could be a touch higher or lower depending on variables. I would say somewhere between 18.5°C and 19.5°C.

That would be fairly exceptional for the first 10 days of August, let alone bloody September!! 

[LetItSnow!]

5 minutes ago, Don said:

That would be fairly exceptional for the first 10 days of August, let alone bloody September!! 

Indeed. Going to take a very big nosedive in temperature to recover to even near normal at this rate.

[Don]

Just now, LetItSnow! said:

Indeed. Going to take a very big nosedive in temperature to recover to even near normal at this rate.

Certainly will.  However, it can be done! 

[snowray]

Could we see a record breaking September to make up for the crappy July and August I wonder? Blinking typical I'm heading away to the Med on the 6th, booked up just before the decent looking charts turned up, and also having taken the advice of a friend from Romney Marsh, a sort of Augur from them parts who insisted that there was no chance of an Indian Summer this year due to the behaviour of swans/birds on the river Sewer. More fool me!

[Don]

17 minutes ago, snowray said:

Could we see a record breaking September to make up for the crappy July and August I wonder? Blinking typical I'm heading away to the Med on the 6th, booked up just before the decent looking charts turned up, and also having taken the advice of a friend from Romney Marsh, a sort of Augur from them parts who insisted that there was no chance of an Indian Summer this year due to the behaviour of swans/birds on the river Sewer. More fool me!

I do wonder if September will be the warmest month of the year, narrowly beating June?!  I think it's probably unlikely, but certainly can't be ruled out going by the current outlook!

[Earthshine]

19.4°C to the 10th would be absolutely insane.  Could we see two 17°C+ CET months this year?

[Frigid]

17 minutes ago, Earthshine said:

19.4°C to the 10th would be absolutely insane.  Could we see two 17°C+ CET months this year?

Nothing special, but it'd be the months you'd least expect. A 17C September would be more outrageous than a 17C June..

[Don]

1 minute ago, Frigid said:

Nothing special, but it'd be the months you'd least expect. A 17C September would be more outrageous than a 17C June..

Of course it would be, considering the 17C June this year was the warmest on record.  That said, a 17C September would only narrowly beat the current warmest on record which is 2006, having a CET of 16.9C.

[Derecho]

From the model output I've got:

EC 12Z = 19.1C to the 10th
GFS 12Z = 18.8C to the 10th

[Don]

4 minutes ago, Derecho said:

From the model output I've got:

EC 12Z = 19.1C to the 10th
GFS 12Z = 18.8C to the 10th

What was the CET for the first 10 days of September last year?  Pretty sure it was in the 18's?

[Derecho]

19 minutes ago, Don said:

What was the CET for the first 10 days of September last year?  Pretty sure it was in the 18's?

17.6C