May 2020 C.E.T. and EWP forecast contests

[mb018538]

12.5c and 72mm please 

[Godber 1]

12.6 and 63mm please.

[J10]

12.5c and 70mm

[damianslaw]

May my favourite month. Can be a tricky month to forecast as we see the atlantic traditionally in its annual slumber state, meaning northerly and easterly airstreams can easily muscle out its influence. High pressure can hang around for quite some time, equally slow moving low pressure can take an age to clear off due to lack of wind. 

Wow 1833 over 15 degrees, preety exceptional stuff. Also interesting to note the very high CET's in long years gone by. 

I'll go 12.7 degrees. An above average month but not especially so, with mixed conditions, some decent lengthy warm sunny weather at times, more so first half, some cooler wetter spells at times, more so second half. Could be some quite cold nights early-mid month as well.

[Don]

12.3C and 67mm, please.

[Roger J Smith]

Table of forecasts for May 2020

_ The numbers in brackets refer to order of entry. You can continue to enter the contests until end of Sunday, 3rd of May with increasing late penalties applied.

_ your later entries are edited in _ to 0001h 2nd _ enter to end of Sunday 3rd

 

CET _ EWP _ FORECASTER _____________________ CET _ EWP _ FORECASTER _______________

17.5 _ 200.0 _ Lettucing Gutted ( 01 ) _______________ 12.3 __ 92.0 _ Bobd29 ( 04 ) ________________ 

13.4 __ 62.0 _ Twilight ( 17 ) ______________________ 12.3 __ 47.0 _ weather-history ( 30 ) ___________ 

13.2 __ 41.2 _ Feb1991Blizzard ( 23 ) _______________12.3 __ 67.0 _ Don ( 48 ) _____________________

13.1 __ 80.0 _ Leo97t ( 16 ) _______________________12.3 __ 64.0 _ Midlands Ice Age ( L1-4 ) _________

13.0 __ 42.2 _ Polar Gael ( 13 ) ____________________12.2 __ 95.0 _ coldest winter ( 25 ) ______________

12.9 __ 67.0 _ brmbrmcar ( 06 ) ____________________12.2 __ 45.0 _ Reef ( 33 ) _____________________

12.9 __ 78.4 _ Kirkcaldy Weather ( 15 ) ______________12.2 __ 64.0 _ Mulzy ( 43 )  ___________________

12.9 __ 31.0 _ I Remember Atlantic 252 ( 20 ) _________12.1 __ 48.0 _ JeffC ( 07 ) ____________________

12.8 __ 70.9 _ CheesepuffScott ( 02 ) _______________12.1 __ 66.0 _ Norrance ( L1-1 ) ________ 

12.8 __ 58.8 _ Emmett Garland ( 24 ) _______________ 12.1 _ ------ _ Quicksilver1989 ( L1-6 ) ____

12.8 __ 64.0 _ General Cluster ( 35 ) ________________12.0 __ 61.0 _ snowray ( 31 ) _________________

12.7 __ 48.0 _ virtualsphere ( 12 ) __________________12.0 __ 55.0 _ DAVID SNOW ( 40 ) ___________

12.7 __ 60.0 _ Summer Blizzard ( 14 ) _______________12.0 _ ------ _ Man with Beard ( 51 ) ___________

12.7 __ ------ _ Dancerwithwings ( 21 ) _______________11.9 __ 84.0 _ Stargazer ( 27 ) _______________

12.7 _ ------ _ sundog ( 40 ) _______________________ 11.9 _ ------ _ Mark Bayley ( 32 ) _____________

12.7 _ ------ _ Damianslaw ( 47 ) ___________________ 11.9 __ 63.1 _ 1990-2019 average ____________

12.7 _ ------ _ Walsall Wood Snow ( L1-5 ) ____________11.8 __ 68.0 __ February1978 ( 50 ) __________

12.6 __ 32.0 _ Earthshine ( 08 ) ____________________11.7 __ 72.9 _ prolongedSnowLover ( 28 ) _____

12.6 __ 65.0 _ NeilN ( 11 ) ________________________11.7 __ 63.6 _ 1981-2010 average ____________

12.6 __ 55.0 _ seaside60 ( 37 ) ____________________11.6 __ 72.0 _ Mr Maunder ( 34 ) _____________

12.6 __ 63.0 _ Godber1 ( 45 ) _____________________ 11.5 _ 103.5 _ Roger J Smith ( 18 ) ___________

12.6 __ 59.0 _ Born From The Void ( L1-3 ) ___________11.5 __ 70.0 _ davehsug ( L1-7 ) _____________

12.5 __ 80.0 _ Dog Toffee ( 09 ) ____________________11.4 __ 97.0 _ Timmytour ( 26 ) ______________

12.5 __ 80.0 _ DR(S)NO ( 22 ) _____________________11.4 __ ------ _ Duncan McAlister ( L2-1 ) _______

12.5 __ 60.0 _ DiagonalRedLine ( 19 ) _______________11.4 __ 75.0 _ Blast from the Past ( L2-2 ) ______

12.5 _ ------ _ Summer Sun ( 29 ) ___________________ 11.3 _ 100.0 _ Relativistic ( 41 ) _____________

12.5 __ 77.0 _ Stationary Front ( 36 ) ________________10.9 _ 115.0 _ B87 ( 05 ) ___________________

12.5 __ 72.0 _ mb018538 ( 44 ) ____________________ 10.9 __ 47.0 _ Let It Snow! ( 49 ) ____________

12.5 __ 70.0 _ J10 ( 46 ) __________________________10.8 __ 75.0 _ daniel* ( 52 ) _________________ 

12.4 _ 100.0 _ Weather 26 ( 03 ) ____________________ 9.9 _ ------ _ Kentish Man ( 42 ) _____________

12.4 __ 61.7 _ SteveB ( 10 ) ________________________9.6 __ 78.0 _ SLEETY ( L1-2 ) ______________

12.4 __ 30.0 _ The PIT ( 38 ) _______________________

12.4 __ 67.0 _ consensus __________________________

52 on-time forecasts plus seven marked one day late, and two that were shown two days late ...

61 in total so far ... median (consensus) is (still) 12.4

_____________________________________________________

EWP forecasts in order

200 LG ... 115 B87 ... 103.5 RJS ... 100 wx26, Rel ...  97 tim ...  95 cw ... 92 bobd

 84 star ...  80 DT, Leo, DR(S) ...  78.4 KW ... 78 SLE^ ... 77 SF ... 75 dan* BFTP^^.. 72.9 pSL ... 72 MrM, mb

 70.9 CPS ...  70 J10, dave^ ...  68 Feb78 ... 67 brm, Don .. (con) .. 66 Norr^ ... 65 NN ... 64 GC, Mul, MIA^

________________ 63.6 1981-2010 avg _________________ 63.1 1990-2019 avg ___________

 63 Godb ...  62 Twi ... 61.7 SteveB ... 61 snow ... 60 SB, DRL ... 59 BFTV^ ... 58.8 EG ... 55 sea, DS

 48 JeffC, virt ... 47 wx-h, LIS ... 45 Reef ... 42.2 PG ... 41.2 Feb91.. 32 Earth .. 31 IRAtl252 ... 30 PIT 

_________________________

45 on time forecasts with five more marked 1d late (^), and one marked 2d (^^) ...

 total 51 so far, median (consensus) 67.0 mm. 

 

 

 

 

Edited May 2, 2020 by Roger J Smith

[LetItSnow!]

sorry to be a pain but i’d like to change my guess to 10.9 and 47mm

[February1978]

11.8c & 68mm please

[Man With Beard]

Upping this to 12C

[Daniel*]

On 29/04/2020 at 00:58, Daniel* said:

11.8C... 85mm

I've had a late change of heart 10.8C and 75mm. Very cool at times not that unsettled though.

Edited April 30, 2020 by Daniel*

[Norrance]

12.1C and 66 mms please.

[feb1991blizzard]

Sticking with mine tentatively - strategy is a late hot spell with southerlies - a risky strategy going well above average because i fully expect it to be below average or average going into last week so if the hot spell doesn't materialise, its a heavy heavy hit in the annual.

[SLEETY]

Looking at current charts it’s going cold for may

 

9.6c

78 mm

[summer blizzard]

Roger, can you just confirm where the first half of May 2008 ranked and whether we have had any high ranking second halfs of May recently.

[BornFromTheVoid]

12.6C and 59mm, thanks

[Midlands Ice Age]

Sorry to be late...

12.3C and 64 mms please.

MIA

 

[seaside 60]

Interesting to note that most people going above the 81-10 average.

[Walsall Wood Snow]

I'll go for 12.7c please

[Derecho]

12.1C, sorry for the lateness

[davehsug]

Late again! 11.5C & 70mm please

[Daniel*]

12 minutes ago, davehsug said:

Late again! 11.5C & 70mm please

Pull yourself together! 

[Roger J Smith]

16 hours ago, summer blizzard said:

Roger, can you just confirm where the first half of May 2008 ranked and whether we have had any high ranking second halfs of May recently.

The running CET for May 2008 peaked at 15.1 on the 12th and by 15th was 14.6, and by 16th 14.3 C. Depending on which of those you consider to be first half of May, the 2008 rank was first from 10th to 14th (had been 1990 from 3rd to 8th -- peak 16.8 on 4th -- then 1804 t1995 with 14.7 on 8th, and 1800 -- 14.7 on 9th -- for one day each), then 2008 was second to 1833 by 15th (1833 was then 14.9) and then again second to 1833 (15.2) by 16th. So 2008 was quite a contender until later in the month and finished just outside the top ten warmest Mays.

May 1834 also had considerable warmth around mid-month and peaked at 14.1 C for its running CET value on 15th and 16th (ranked 3rd on those dates, it finished on 13.0). 

The highest running CET (note 1788 started warm) of top ten Mays for which we have daily data compared to their finish would look like this:

YEAR ___ Max running CET __ Finished on

1833 ____ 15.6 ( 25th ) _______ 15.1

1848 ____ 14.0 (17,18,29th) ___ 13.9

1788 ____ 14.1 ( 28th ) _______ 13.8 (note had been 15.2, 14.5 on 1st, 2nd, fell to 12.0 by 5th)

1758, 1727, 1726 _ no data ____13.8, 13.6, 13.4

1808 ____ 14.1 ( 17th ) _______ 13.7 

1992 ____ 13.6 (30th,31st) ____ 13.6

1784 ____ 13.6 (26,27,28,30th)_ 13.5 (was only at 9.2 on 6th ! )

1868 ____ 13.5 ( 31st ) _______ 13.5 (a secondary max of 13.3 on 21st, 22nd)

1919 ____ 13.5 ( 31st ) _______ 13.5 (steady climb after 19th but slight peak of 12.9 on 17th before that)

1947 ____ 13.5 ( 31st ) _______ 13.5 (had reached 12.4 on 14th, stayed below that until 26th)

1952 ____ 13.6 (26,27,28th) ___ 13.4

2008 ____ 15.1 ( 12th ) _______ 13.4 (

1804 ____ 13.5 ( 20th ) _______ 13.3 ( was 15.0 on 6th and 14.8, 14.7 next two days )

1964 ____ 13.3 ( 31st ) _______ 13.3 ( slow rise from steady 12.3 around 19th-22nd)

(then more recently after another early case 1743 - 13.3 - with no data...)

2017 ____ 13.2 ( 31st ) _______ 13.2 ( was at 11.5 on 16th )

2018 ____ 13.2 ( 31st ) _______ 13.2 ( was at 12.0 on 16th )

-------------------------------------------------------------------------------------------------

Other than 1834 as noted, no other May not in this list reached 14 C at any point in the second half of the month.

---------------------- ========================= -----------------------------

Now, as to warm second halves, obviously 2017 will be high on that list, so here's the top values for 17th to 31st averages (all time, you can find the more recent ones in this list) ... rank applies to the 248 years 1772 to 2019. I placed the 16th to 31st values in brackets if that's your preferred second half range, many are identical anyway. This list includes all years with averages in that period over 14.5. 

Rank 17-31 __ Year __ Average (with 16-31 avg)

01 _________ 1992 __ 16.1 (15.9)

02 _________ 1922 __ 15.9 (15.6)

03 _________ 1784 __ 15.2 (15.2)

04t_________ 1788 __ 15.1 (15.0)

04t_________ 2017 __ 15.1 (15.1)

06t_________ 1833 __ 15.0 (15.3)

06t_________ 1918 __ 15.0 (15.0)

08 _________ 1964 __ 14.8 (14.7)

09t_________ 1868 __ 14.7 (14.5)

09t_________ 1947 __ 14.7 (14.5)

11 _________ 2018 __ 14.6 (14.4)

12t_________ 1822 __ 14.5 (14.4)

12t_________ 1952 __ 14.5 (14.7)

12t_________ 2012 __ 14.5 (14.1)

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

So we have seen three of the top fourteen in this past decade (2012,17,18) and the warmest as recently as 1992. 

Hope that gives you the info you were seeking. 

If outcomes as different as 1922 and 1868 can make the list, I guess it says very little of direct relevance to the summer forecast. 

 

Edited May 2, 2020 by Roger J Smith

[Roger J Smith]

1981-2010 CET May averages and extremes 1772-2019

 

DATE ____ AVG __ CUM AVG _______ MAX yr ___ MIN yr _______ Running CET extremes

___ 01 ___ 10.6 ___ 10.6 ________16.1 1990,2005 _ 4.2 1866 ____ 16.1 1990,2005_ 4.2 1866

___ 02 ___ 10.4 ___ 10.5 __________ 16.4 1966 __ 3.8 1979 _____ 15.9 1966 ___ 4.1 1979

___ 03 ___ 10.5 ___ 10.5 __________ 17.7 1990 __ 3.1 1877 _____ 16.4 1990 ___ 4.3 1979

___ 04 ___ 10.3 ___ 10.5 __________ 18.0 1834 __ 3.2 1877 _____ 16.8 1990 ___ 4.4 1979

___ 05 ___ 10.6 ___ 10.5 __________ 16.7 1800 __ 4.0 1979 _____ 16.5 1990 ___ 4.3 1979

___ 06 ___ 11.0 ___ 10.6 __________ 18.8 1867 __ 4.4 1831 _____ 16.0 1990 ___ 4.6 1877, 1979

___ 07 ___ 11.0 ___ 10.7 __________ 16.9 2018 __ 4.1 1879 _____ 15.2 1990 ___ 5.1 1782, 1877, 1979

___ 08 ___ 10.9 ___ 10.7 __________ 17.8 2016 __ 2.9 1861 _____ 14.7 1804, 1995 _ 5.2 1782

___ 09 ___ 10.7 ___ 10.7 _______ 17.6 1945,2016 _ 5.7 1837 _____ 14.7 1800 ___ 5.6 1782

___ 10 ___ 10.8 ___ 10.7 __________ 18.2 1959 __ 4.1 1879  _____ 14.7 2008 ___ 6.0 1782

___ 11 ___ 11.1 ___ 10.7 __________ 18.6 2008 __ 4.1 1773  _____ 15.0 2008 ___ 6.3 1782, 1879

___ 12 ___ 11.3 ___ 10.8 __________ 18.8 1945 __ 4.4 1816  _____ 15.1 2008 ___ 6.6 1782

___ 13 ___ 11.6 ___ 10.8 __________ 17.4 1959 __ 5.0 1915  _____ 15.0 2008 ___ 6.9 1879, 1902

___ 14 ___ 11.7 ___ 10.9 __________ 18.8 1992 __ 3.9 1839  _____ 14.9 2008 ___ 6.7 1902

___ 15 ___ 11.7 ___ 11.0 __________ 20.0 1833 __ 4.3 1839  _____ 14.9 1833 ___ 6.7 1902

___ 16 ___ 11.5 ___ 11.0 __________ 20.0 1808 __ 5.2 1996  _____ 15.2 1833 ___ 6.9 1902

___ 17 ___ 11.3 ___ 11.0 __________ 19.7 1833 __ 3.6 1935  _____ 15.4 1833 ___ 7.1 1855, 1902

___ 18 ___ 11.4 ___ 11.0 __________ 19.1 1952 __ 4.1 1872  _____ 15.4 1833 ___ 7.2 1855, 1902, 1996

___ 19 ___ 11.8 ___ 11.1 __________ 20.4 1868 __ 5.2 1872  _____ 15.4 1833 ___ 7.2 1902

___ 20 ___ 12.3 ___ 11.1 __________ 17.8 1916 __ 5.5 1907  _____ 15.4 1833 ___ 7.2 1902

___ 21 ___ 12.1 ___ 11.2 __________ 18.8 1916 __ 5.7 1894  _____ 15.4 1833 ___ 7.2 1902

___ 22 ___ 12.2 ___ 11.2 __________ 19.5 1918 __ 5.0 1867  _____ 15.4 1833 ___ 7.3 1902

___ 23 ___ 12.8 ___ 11.3 __________ 19.5 1922 __ 4.9 1867  _____ 15.5 1833 ___ 7.6 1902

___ 24 ___ 13.3 ___ 11.4 __________ 18.8 1953 __ 5.7 1867  _____ 15.5 1833 ___ 7.9 1902

___ 25 ___ 12.5 ___ 11.4 __________ 21.0 1953 __ 6.5 1814  _____ 15.6 1833 ___ 8.0 1885

___ 26 ___ 12.4 ___ 11.5 ________18.7 1784,2017__4.6 1821_____ 15.5 1833 ___ 8.1 1782, 1885

___ 27 ___ 12.1 ___ 11.5 __________ 19.0 1788 __ 6.6 1984  _____ 15.4 1833 ___ 8.2 1885

___ 28 ___ 12.3 ___ 11.5 __________ 20.6 1847 __ 6.2 1869  _____ 15.3 1833 ___ 8.5 1782, 1885, 1996

___ 29 ___ 12.8 ___ 11.6 __________ 21.2 1780 __ 6.2 1869 _____ 15.2 1833 ___ 8.7 1782,1879,1902,1996

___ 30 ___ 13.1 ___ 11.6 __________ 21.0 1944 __ 4.9 1807 _____ 15.1 1833 ___ 8.7 1817, 1902

___ 31 ___ 13.3 ___ 11.7 __________ 20.5 1947 __ 6.4 1802  _____ 15.1 1833 ___ 8.7 1817#

# 8.7 was lowest during daily data period but 1698 finished on 8.5 and 1740 on 8.6, these could have had lower running CET values at various points before 31st as well. 

___________________________________________________________________________

Top ten for May and all 20.0+

 1. 21.2 (29th, 1780)

 2. 21.1 (29th, 1944)

 3. 21.0 (25th, 1953), 21.0 (30th, 1944)

 5. 20.8 (29th, 1947)

 6. 20.6 (28th, 1847)

 7. 20.5 (31st, 1947)

 8. 20.4 (19th, 1868)

 9. 20.0 (15th, 1833) 20.0 (16th, 1808), 20.0 (31st, 1781)

(19.9 on 30 May 1947)

_____________________________________________________________________________

In researching that list, found this remarkable sequence in May 1807 ... 19.8 on 25th (record for date is 21.0 in 1953) to 4.9 C on 30th (record minimum).

It is also interesting to note that all of these warm days occurred before or during May 1953. 

The warmest May day since the end of May 1953 has been 19.4 (31 May 1978). The warmest since then was 18.9 (31 May 2003). 

We seem very overdue for some record warmth in mid to late May to add some more 20+ days to this list. But recent years have confined themselves to lower values in the first half of May (plus the tied value of 18.7 on 26th of 2017).

[Summer Sun]

9.9c to the 1st

0.4c above the 61 to 90 average
0.7c below the 81 to 10 average

___________________________

Current high this month 9.9c to the 1st
Current low this month 9.9c to the 1st

[summer blizzard]

Surprised 2017 was so warm in the second half, i recall it being warm but not exceptional. 2018 is probably about right.

It really shows the consistency of 1833.