December 2023 C.E.T. and EWP forecast contests -- start of 2023-24 contest year -- all welcome

[Roger J Smith]

 

Table of entries for December 2023

 

CET _ EWP __ FORECASTER (Order of entry) ____________ CET _ EWP _ FORECASTER (Order of entry) _________

7.0 __ --- --- __ Typhoon John ( 11 ) ______________________ 4.8 _ 103.6 __ 1991-2020 average ___________________

6.3 _ 108.0 __ davehsug ( 41 ) ___________________________ 4.8 __ 56.0 __ summer shower ( 28 ) _________________

6.0 _ 136.0 __ virtualsphere ( 6 ) ________________________ 4.8 _ --- --- __ Mark Bayley ( 45 ) _______________________

6.0 __ 50.0 __ syed2878 ( 16 ) ___________________________ 4.7 _ 115.0 __ WYorksWeather ( 33 ) __________________

6.0 __ --- --- __ Froze were the Days ( 38 ) _______________ 

5.9 __ --- --- __ Summer Sun ( 37 ) ________________________4.5 __ 97.4 __ 1981-2010 average ____________________

5.8 __ 80.0 __ The PIT ( 18 ) ______________________________ 4.5 __ 60.0 __ Leo97t ( 26 ) ___________________________ 

5.8 __ 87.0 __ Reef ( 32 ) _________________________________ 4.4 __ 85.0 __ Weather26 ( 2 ) ________________________ 

5.7 _ 112.0 __ I remember Atlantic252 ( 27 ) ____________ 4.4 __ 77.0 __ Somerset girl ( 49 ) ____________________

5.6 __ 74.0 __ summer blizzard ( 20 ) ____________________ 4.3 __ 99.0 __ Wold Topper ( 57 ) ____________________

5.6 _ 129.0 __ noname_weather ( 39 ) ___________________ 4.2 __ 80.0 __ John88b ( 8 ) ___________________________

5.5 _ 118.0 __ chilly milly ( 13 ) ___________________________ 4.2 __ 72.0 __ gazse9 ( 9 ) _____________________________

5.4 _ 130.0 __ Don ( 34 ) _________________________________ 4.2 __ 88.0 __ summer18 ( 17 ) ________________________

5.4 _ 120.0 __ J 10 ( 53 ) __________________________________ 4.2 __ 90.0 __ Mulzy ( 46 ) _____________________________

5.3 _ 119.0 __ feb1991blizzard ( 30 ) _____________________4.1 __ 89.1 __ average of all data (CET 1659-2022, EWP 1766-2022)   

5.3 _ 121.5 __ snowray ( 40 ) _____________________________4.1 __ 81.0 __ Alexis J9 ( 4 ) _____________________________

5.3 _ 110.0 __ seaside60 ( L1-2 ) _________________________

5.2 _ 135.0 __ Frigid ( 35 ) ________________________________ 4.1 __ 95.0 __ Metwatch ( 44 ) __________________________

5.2 _ 110.0 __ Addicks Fan 1981 ( 48 ) ___________________ 4.0 _ 100.0 __ DR(S)NO ( 29 ) ____________________________

5.2 _ 114.0 __ February1978 ( 55 ) _______________________ 4.0 __ --- --- __ damianslaw ( 43 ) _________________________

5.1 __ 96.0 __ moorlander ( 7 ) ___________________________ 3.9 __ 51.0 __ shillitocettwo ( 22 ) ________________________ 

5.1 __ 63.0 __ SteveB ( 10 ) _______________________________ 3.9 __ 75.0 __ daniel* ( 56 ) ______________________________

5.1 __ 98.0 __ rwtwm ( 36 ) _______________________________ 3.8 __ 75.0 __ stewfox ( 12 ) _____________________________

5.1 __ 67.0 __Mr Maunder ( 42 ) __________________________3.8 _ 105.0 __ Midlands Ice Age ( 50 ) ___________________ 

5.0 __ 83.0 __ Bobd29 ( 3 ) ________________________________3.7 __ 81.0 __ Emmett Garland ( 31 ) ____________________  

5.0 __ 80.0 __ Earthshine ( 14 ) ____________________________3.6 __ 21.0 __ Neil N ( 21 )  ______________________________

____ __ ____ __ ____ ____ ____ ________________________________3.6 __ 72.0 __ Weather Observer ( 51 ) __________________ 

____ __ ____ __ ____ ____ ____ ________________________________3.3 __ --- --- __ Kentish Man ( 54 ) __________________

4.9 _ 106.3 __ 1993-2022 average _________________________ 3.2 __ 71.0 __ jonboy ( 24 ) ______________________________

_____________________________________________________________3.1 _ 124.0 __ godber 1 ( 52 ) ___________________________

4.9 __ 88.0 __ methuselah ( 5 ) _____________________________3.0 _ 110.0 __ Jeff C ( 1 ) _________________________________

4.9 __ 59.0 __ dancerwithwings ( 19 ) ______________________ 2.9 __ 64.7 __ Roger J Smith ( 23 ) _______________________

____ ____ __ __ __ ___ ___ ___ ___ ___ __________________________2.8 __ 64.0 __ Stationary Front ( 25 ) ____________________

____ ____ __ __ __ ___ ___ ___ ___ ___ __________________________2.8 __104.0 __ Let It Snow! ( L1-1 ) ______________________

4.8 __ 88.0 __ Consensus __________________________________ 2.4 _ 124.0 __ prolongedSnowLover ( 47 ) ______________

_____________________________________________________________2.0 __ 96.5 __ Polar Gael ( 15 ) __________________________

57 on-time entries, and two 1d late so far, 59 total ... median (consensus) 4.8 C 

---------- 

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

 

EWP forecasts in order

136_virt .. 135_Frig .. 130_Don .. 129_non .. 124_pSL, godb .. 121.5_snow .. 120_ J10 ..

119_feb91 .. 118_cm .. 115_WYorks .. 114_Feb78 .. 112_IRem .. 110_ Jeff, Add,sea^ .. 108_ dave ..

106.3 _93-22 .. 105_mia .. 104_LIS^ ..103.6 _91-20 .. 100_DR(S) .. 99_WT .. 98_rwtwm .. 97.4 _81-10 ..

 96.5_PG .. 96_moor .. 95_Met .. 90_Mul ..  89.1 _all ...88_meth, sum18 .. 88.0_con .. 87_Reef ..

 85_wx26 .. 83 _bobd .. 81_Al J9, EG .. 80_john, earth, PIT .. 77_sg .. 75_stew, dan ..

 74_sb ... 72_gaz, WxOb .. 71_jon .. 67_MrM .. 64.7 _RJS .. 64_SF .. 63 _Ste .. 60_leo ..

 59_dww ..  56_sumsh .. 51_shil .. 50_syed .. 21_NN

_________

51 on-time entries, and two late (^) 1d, 53 total ... median (consensus) 88.0 mm.

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

 

<< LATER ENTRIES will be added to end of Sunday, 3 Dec >>>

 

Edited December 1, 2023 by Roger J Smith

[Wold Topper]

4.3°c and 99mm please Rodger, apologies for the late entry,

[Roger J Smith]

3 minutes ago, Wold Topper said:

4.3°c and 99mm please Rodger, apologies for the late entry,

Not very late, in fact I was posting as you were, so I will call it last of non-late entries. Table adjusted. 

Late period starts now ... tick tock 

[Wold Topper]

9 minutes ago, Roger J Smith said:

Not very late, in fact I was posting as you were, so I will call it last of non-late entries. Table adjusted. 

Late period starts now ... tick tock 

A gentleman, Thank you 

[LetItSnow!]

How wonderful, I’m already late  

2.8C and 104mm

I’m assuming that the intense cold being modelled with at least have one semi successful go at attacking us, but also thinking not overly dry from the Atlantic trying to wrangle its way in but (hopefully) losing.

[seaside 60]

Another month forgotten to do on time.

Where do you go this month.

Think go with the average warmer trend and hope I am wrong.

5.3c

110mm

[damianslaw]

Interested to know coldest 1-3 Dec mean temp. This year will produce a very cold one, possibly sub zero. We had cold starts to Dec in 2008, 2010 - notably so, 2012, 2017. 2019 - coldest spell of that winter!, 2020 and 2021. 

[Roger J Smith]

4 hours ago, damianslaw said:

Interested to know coldest 1-3 Dec mean temp. This year will produce a very cold one, possibly sub zero. We had cold starts to Dec in 2008, 2010 - notably so, 2012, 2017. 2019 - coldest spell of that winter!, 2020 and 2021. 

Coldest running means (all subzero cases) for 1-3 Dec, with daily values and notes on following trends:

1879 ___ -3.2 C (-1.1, -4.2, -4.2) ___ stayed very cold to 27 Dec, mild by NYD 1880 (10.4 C)

1796 ___ -2.8 C (-2.1, -4.7, -1.6) ____ severe cold around 25 Dec (-10.8)

2010 ___ -2.0 C (-2.0, -1.4, -2.6) ____ severe cold especially 18-27 Dec, milder trend afterwards

1856 ___ -1.5 C (-0.4, -2.6, -1.6) ____ very mild 6-10 Dec, several daily records near 12 C

1947 ___ -0.9 C (-3.0, -0.5, +0.7) ____ mild winter followed, (2-5 Jan near 10 C), Jan 1948 very mild and wet

1874 ___ -0.7 C (+0.4, -2.3, -0.1) ____ cold month, coldest 22-24 Dec

1846 ___ -0.6 C (-1.4, +0.7, -1.0) ____ very cold 13-15 Dec (around -4 C)

1869 ___ -0.5 C (-0.1, -0.9, -0.6) ____ variable and near average for era

1859 ____ 0.0 C (+1.9, +0.3, -2.1) ___ record cold 14-18 Dec (very mild by 31 Dec)

1889 ___ +0.2 C (+2.2, -0.8, -0.8) ___ generally mild after mid-Dec

In recent years, beside 2010, also +1.0 C in 2008 (+0.6, +0.6, +1.8) __ very mild 21-22 Dec, cold Jan 2009

In 2012, cold on 30 Nov and 1 Dec (1.2, 1.1) stayed rather cold to about 13 Dec then rather mild until mid-Jan 2013 cold spell

In 2017 coldest day 30 Nov (1.2) and in 2019 it was 2 Dec at 1.4. Averages around 2 C for these recent cases. 

________________________________

In general, a trend often seen before in these cold starts to Dec is an eventual reversal if not fairly soon, then around New Years. Best chance for a return of severe cold appears to be in period 21-28 Dec. None of these winters became classic cold winters, one could use an expression like premature ejection of Russian origins (don't blame me) ... even so, 1796 did manage to reload and produce a monthly record cold day (25 Dec 1796).

It is also noteworthy that aside from 2010, cold spells in early Dec are clustered in a period of 1846 to 1890. (Dec 1890 not in list but very cold late Nov and most of Dec, 1-3 Dec gave a relaxation to +3.2, +1.7, +2.6). Average of -2.3 for 27-29 Nov (-2.7, -2.5, -1.8)

[Roger J Smith]

Average and extreme CET values 1772 to 2022

All data shown in these tables have been adjusted to v2.0

 

 _______________________ Daily record values ____ Extremes of running CET

DATE ___ CET __ CET cum _____ MAX _______ MIN _______ MAX _______ MIN

01 _____ 5.6 ___ 5.6 ______ 12.1 (1775) ___ --3.0 (1947) ____ 12.1 (1775) __ --3.0 (1947)

02 _____ 5.6 ___ 5.6 ______ 12.0 (1985) ___ --4.7 (1796) ____ 11.1 (1775) __ --3.4 (1796)

03 _____ 5.8 ___ 5.7 ______ 12.0 (1985) ___ --4.2 (1879) ____ 10.8 (1775) __ --3.2 (1879)

04 _____ 5.9 ___ 5.7 ______ 12.0 (1888) ___ --3.6 (1879,1925) _10.8 (1985) __ --3.3 (1879)

05 _____ 6.0 ___ 5.8 ______ 12.7 (1898) ___ --3.7 (1844) ____ 10.4 (1898,1985) _ --3.3 (1879)

06 _____ 4.8 ___ 5.6 ______ 12.1 (1898) ___ --5.5 (1844) ____ 10.7 (1898) __ --3.4 (1879)

07 _____ 4.7 ___ 5.5 ______ 12.1 (1856) ___ --5.3 (1879) ____ 10.2 (1898, 2015) _ --3.7 (1879)

08 _____ 4.3 ___ 5.3 ______ 12.0 (1856) ___ --5.4 (1807) ____ 10.4 (2015) __ --3.4 (1879)

09 _____ 4.3 ___ 5.2 ______ 11.7 (1934) ___ --4.0 (1803) ____ 10.1 (2015) __ --3.0 (1879)

10 _____ 4.2 ___ 5.1 ______ 10.7 (1856,1997) __ --4.5 (1784) __ 9.8 (2015)_--2.6 (1879)

11 _____ 4.1 ___ 5.0 ______ 12.4 (1994) ___ --6.7 (1784) ____ 9.7 (1898) __--2.6 (1879)

12 _____ 4.0 ___ 4.9 ______ 12.7 (1994) ___ --8.7 (1981) _____ 9.7 (1898) __ --2.3 (1879)

13 _____ 4.5 ___ 4.9 ______ 11.5 (1918) ___ --6.7 (1981) _____ 9.5 (2000) __ --2.1 (1879)

14 _____ 4.2 ___ 4.9 ______ 11.5 (2006) ___ --5.5 (1878) _____ 9.3 (1898) __ --1.7 (1879)

15 _____ 4.5 ___ 4.8 ______ 11.1 (1985) ___ --5.4 (1788)*_____ 9.1 (1898) __ --1.3 (1879)

16 _____ 4.4 ___ 4.8 ______ 11.4 (2015) ___ --6.4 (1859) _____ 9.0 (2015) __ --1.0 (1844, 1879)

17 _____ 4.3 ___ 4.8 ______ 12.5 (2015) ___ --7.5 (1859) _____ 9.2 (2015) __ --1.0 (1879)

18 _____ 4.2 ___ 4.7 ______ 12.5 (2015) ___ --7.0 (1859) _____ 9.4 (2015) __ --0.9 (1878,79)

19 _____ 4.2 ___ 4.7 ______ 13.0 (2015) ___ --6.8 (2010) _____ 9.6 (2015) __ --0.8 (1879)

20 _____ 3.6 ___ 4.6 ______ 11.1 (1833) ___ --7.0 (2010) _____ 9.7 (2015) __--0.9 (1878)

21 _____ 4.0 ___ 4.6 ______ 11.4 (1971) ___ --5.9 (2010) _____ 9.7 (2015) __ --1.0 (2010)

22 _____ 4.3 ___ 4.6 ______ 11.5 (1991) ___ --5.7 (1890) _____ 9.7 (2015) __ --1.0 (1878, 2010)

23 _____ 4.6 ___ 4.6 ______ 11.6 (1991) ___ --6.2 (1870) _____ 9.7 (2015) __ --1.1 (1878, 2010)

24 _____ 4.6 ___ 4.6 ______ 10.7 (1843) __ --6.7 (1830,1870) __ 9.6 (2015) _ --1.3 (1878)

25 _____ 4.3 ___ 4.6 ______ 10.4 (1824) __ --10.8 (1796) _____ 9.5 (2015) __ --1.5 (1878)

26 _____ 4.2 ___ 4.6 ______ 11.0 (2011) __ --5.4 (1786, 1798) __ 9.6 (2015) _ --1.5 (1878)

27 _____ 3.8 ___ 4.5 ______ 10.8 (2015) ___ --8.4 (1798) _____ 9.6 (2015) __ --1.4 (2010)

28 _____ 3.9 ___ 4.5 ______ 11.3 (1987) ___ --8.2 (1798) _____ 9.6 (2015) __ --1.3 (2010)

29 _____ 3.7 ___ 4.5 ______ 11.9 (1987) ___ --5.3 (1908) _____ 9.7 (2015) __ --1.1 (2010)

30 _____ 4.0 ___ 4.5 ______ 11.3 (2021) ___ --6.0 (1870) _____ 9.7 (2015) __ --0.9 (2010)

31 _____ 4.2 ___ 4.5 ______ 12.9 (2021) ___ --7.1 (1783) _____ 9.6 (2015) __ --0.8 (1890) (-0.7 2010)

* close call last year -4.4 15 Dec ... +9.3 on 31 Dec

________________________________________________________________ 

So from this we see that 2015 had one crack at being warmest Dec (7th to 10th), fell out of first place for a while, then resumed the lead from 16th to end of month. The closest to 2015 that any year came after the 20th was 8.7 (1898 - 21st). As for 2010, it moved into first by the 21st, had a running battle with 1878, shook that off but got nipped at the very end by 1890 which never held the lead at any other stage. Other noteworthy late negative running CET values would include 1788 which was -0.4 on 23rd and -0.3 on 30th-31st, 1796 which was running at -1.0 from 26th to 28th, 1844 which was -0.2 on 25th, 1879 held on at -0.4 to 25th, and more recently 1981 was running at -0.2 from 24th to 27th (finished 0.3). 

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

1991-2020 daily and cumulative CET values

01 ___ 5.6 __ 5.7 _______ 11 ___ 4.7 __ 5.4 _______ 21 ___ 4.5 __ 5.0 

02 ___ 5.9 __ 5.8 _______ 12 ___ 4.7 __ 5.3 _______ 22 ___ 5.2 __ 5.0 

03 ___ 5.9 __ 5.8 _______ 13 ___ 4.9 __ 5.3 _______ 23 ___ 5.5 __ 5.1 

04 ___ 5.4 __ 5.7 _______ 14 ___ 4.5 __ 5.2 _______ 24 ___ 4.9 __ 5.1 

05 ___ 5.5 __ 5.7 _______ 15 ___ 4.9 __ 5.2 _______ 25 ___ 4.4 __ 5.0 

06 ___ 5.3 __ 5.6 _______ 16 ___ 5.0 __ 5.2 _______ 26 ___ 4.4 __ 5.0 

07 ___ 5.3 __ 5.6 _______ 17 ___ 4.6 __ 5.2 _______ 27 ___ 4.0 __ 5.0 

08 ___ 5.3 __ 5.5 _______ 18 ___ 4.8 __ 5.1 _______ 28 ___ 3.9 __ 4.9 

09 ___ 5.0 __ 5.5 _______ 19 ___ 4.7 __ 5.1 _______ 29 ___ 3.9 __ 4.9 

10 ___ 5.1 __ 5.4 _______ 20 ___ 4.0 __ 5.1 _______ 30 ___ 4.2 __ 4.9 

________________________________________________ _31 ___ 4.5 __ 4.8

There is a noticeable spike in mean temperature around the 22nd-23rd Dec evident 1981-2010 but stronger by 1991-2020. 

 

 

[Frigid]

CET Zone looks very cold today, possible ice day in some places if the fog lingers.

[Relativistic]

-0.5°C yesterday -- season's first subzero mean

[Summer Sun]

-0.5c to the 1st

5.1c below the 61 to 90 average
6.1c below the 81 to 10 average

[Frigid]

52 minutes ago, Relativistic said:

-0.5°C yesterday -- season's first subzero mean

Conveniently on the first day of meteorological winter. Today will certainly be another one. 

[WYorksWeather]

For my 12 months above 1961-1990 thread, was having a look at CET for the next few days. I think the most likely outcome to the 5th is probably around 0C give or take a degree.

Beyond that, uncertainty reigns I think...

 

Edited December 2, 2023 by WYorksWeather
Can't spell...

[Summer Sun]

-1.0c to the 2nd

5.5c below the 61 to 90 average
6.6c below the 81 to 10 average

[Metwatch]

The CET yesterday of -1.5C was the coldest 2nd December in 130 years! Colder than 2010 by 0.1C as well.

[Summer Sun]

0.1c to the 3rd

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

[Roger J Smith]

So that is the tenth coldest start to DEC in 252 tries, see list of top ten above ... replaces 1889 (0.2) in tenth. 

Looks like a brief spell of higher readings later in week but this won't be a one and done sort of thing like the cold in 1947-48 for instance. I think the Russian bear will be prowling at later points of the winter. 

[WYorksWeather]

2 hours ago, Roger J Smith said:

So that is the tenth coldest start to DEC in 252 tries, see list of top ten above ... replaces 1889 (0.2) in tenth. 

Looks like a brief spell of higher readings later in week but this won't be a one and done sort of thing like the cold in 1947-48 for instance. I think the Russian bear will be prowling at later points of the winter. 

To be fair, it does look at this stage like later in the week could be quite mild indeed - possibly 8C or 9C daily averages on Friday and Saturday for the CET region. Before that though we have a likely colder day tomorrow, and Weds and Thurs maybe near average? Difficult one to predict, but I'd probably guess that we'll be near normal on the CET by the end of the week. 

[damianslaw]

Cold spells early December rarely seem to hold through the month, 2010 an exception. Cases in point include 2008, 2012, 2017, 2019 and 2022.. 2023 joining the list though a more fleeting affair.

Cases where Dec has opened mild but turned much colder include 1995 and 2009.

Expecting to be close to average this time next week, with a milder spell Thursday onwards cancelling out the colder start.

[LetItSnow!]

A cold opening transiting to a mild, perhaps very mild couple of days around the 8th/9th. The charts show moisture laden southwesterly winds so I imagine very dull with little diurnal range and probably some very mild returns due to mild, cloudy nights. Probably will work out not too

far from average at that point. From there, really it could go anywhere. 

[Summer Sun]

1.3c to the 4th

3.2c below the 61 to 90 average
4.4c below the 81 to 10 average

[WYorksWeather]

23 hours ago, LetItSnow! said:

A cold opening transiting to a mild, perhaps very mild couple of days around the 8th/9th. The charts show moisture laden southwesterly winds so I imagine very dull with little diurnal range and probably some very mild returns due to mild, cloudy nights. Probably will work out not too

far from average at that point. From there, really it could go anywhere. 

Based on today's UKV with some likely 10C+ CET means on the 9th and 10th, we may well be around 0.5C to 1.0C or so above the 1961-1990. Assuming the 5th and the 6th net out to something around average, I could see 9C being averaged for the 7th-10th. Combining that, we'd end up with an average of 7.5C for the 5th-10th, which then combined with the existing value of 1.3C, gives an average of 5C by the 10th, and if you consider projections for the 11th, slightly higher by then.

Obviously low confidence on the exact value, but I'd be very surprised if we were still below average by the 11th, and only a little surprised if we were a full degree above 1961-1990.

[Summer Sun]

2.0c to the 5th

2.5c below the 61 to 90 average
3.8c below the 81 to 10 average

[The PIT]

Sunny Sheffield at 0.8C -5.9C below average, Rainfall 37.6mm 43% of the monthly average.

Already looking like it will be a very wet month. Now the 4th wettest year on record.