November 2023 C.E.T. and EWP contests -- final month of the 2022-23 competitions

[Don]

56 minutes ago, summer blizzard said:

While I doubt we will see such a contrast, do we know what the first halves of 2005 and 2010 averaged.

The first half of November 2005 particularly very mild/warm and could have been record breaking?

[Metwatch]

Might be a little less wet for some central and eastern areas through next week compared to recent.

EWP already at 26mm first 2 days and will still continue to go up, probably won't be a record breakingly wet month, but still far from dry.

A good bet from me would be for the EWP to finish somewhere in the 100-120mm range, though still quite early on in the month for much certainty.

[Roger J Smith]

9 hours ago, summer blizzard said:

While I doubt we will see such a contrast, do we know what the first halves of 2005 and 2010 averaged.

 

2005 fell 3.8 (9.9 to 6.1) and 2010 3.0 (8.1 to 5.1) in CET v2.0 data; here's where those large drops in CET rank in top ten of falls from CET 1-15 to CET 1-30. 

2005 was a clear winner in this regard. ...

 

Rank _____ NOV ____ CET 1-15 ___ CET 1-30 ____ Decrease

_ 01 _______2005 _____ 9.9 ________ 6.1 __________ 3.8 

_ 02 _______1904 _____ 8.3 ________ 5.2 __________ 3.1

_t03 _______1779 _____ 8.7 ________ 5.7 __________ 3.0 

_t03 _______2010 _____ 8.1 ________ 5.1 __________ 3.0

_t05 _______1815 _____ 6.3 ________ 3.4 __________ 2.9

_t05 _______1977 _____ 9.3 ________ 6.4 __________ 2.9

_t05 _______1993 _____ 7.4 ________ 4.5 __________ 2.9

_ 08 _______1973 _____ 8.8 ________ 6.0 __________ 2.8

_t09 _______1787 _____ 7.1 ________ 4.5 __________ 2.6

_t09 _______1938 ____ 12.0 ________ 9.4 __________ 2.6

___________________

Nov 2010 was 9.0 after 10 days (10.6 after 1-7) and the drop was well underway by 15th. 

Nov 2005 was 10.8 after 10 days and 11.0 after 11 days, a drop set in after that.

Nov 1977 was 10.2 after 11 days also. 

 

[Midlands Ice Age]

11 hours ago, Metwatch said:

Might be a little less wet for some central and eastern areas through next week compared to recent.

EWP already at 26mm first 2 days and will still continue to go up, probably won't be a record breakingly wet month, but still far from dry.

A good bet from me would be for the EWP to finish somewhere in the 100-120mm range, though still quite early on in the month for much certainty.

Could be anything...

I noticed a 148mms by the 12th just across the Channel on the trailing cold front.

If that stuck around a bit....

MIA

Edited November 5, 2023 by Midlands Ice Age

[Roger J Smith]

There are two large energy peaks near end of Nov well beyond event horizon today, that I believe will unleash large rainfalls so if we get to near 100 mm before 24 Nov it could begin to escalate near end of Nov to verify large forecasted amounts. Some of it could fall as snow in n England and s Scotland. Timing around 25-26 Nov and 29-30 Nov for peaks. 

 

[Summer Sun]

9.3c to the 4th

2.8c above the 61 to 90 average
0.4c above the 81 to 10 average

 

Edited November 5, 2023 by Summer Sun

[Roger J Smith]

EWP now around 40 mm and GFS indicates heavy rainfalls in parts of northwest England and Wales, but 20-30 mm additional in parts of eastern and southern England, so a blend looks like 50 mm additional to 21st, 90 mm total by then.

CET looks to stay rather mild with two peaks near record highs but near average other days, will speculate that we stay around 9 C well into the month with oscillations in the range 9 to 9.5. Any later cold spell will need to be quite powerful to serve the interests below 8.0 end of Nov. 

Current GFS 16-day charts do not look as though cold air will be advancing, and a bland westerly flow is indicated then, after some windy days around 17-18 Nov. 

[WYorksWeather]

33 minutes ago, Roger J Smith said:

EWP now around 40 mm and GFS indicates heavy rainfalls in parts of northwest England and Wales, but 20-30 mm additional in parts of eastern and southern England, so a blend looks like 50 mm additional to 21st, 90 mm total by then.

CET looks to stay rather mild with two peaks near record highs but near average other days, will speculate that we stay around 9 C well into the month with oscillations in the range 9 to 9.5. Any later cold spell will need to be quite powerful to serve the interests below 8.0 end of Nov. 

Current GFS 16-day charts do not look as though cold air will be advancing, and a bland westerly flow is indicated then, after some windy days around 17-18 Nov. 

As I mentioned on the model thread, there's not much signal for anything below average on the ECM either.

ECM meteograms are produced only for larger towns/cities, so I used Luton for Rothamsted:

Pershore:

Clitheroe instead of Stonyhurst:

As mentioned on the model thread, the model climatology is roughly analogous to a 20-year mean, i.e. 2004-2023. Overall, all these stations look average at the lowest for the model climate period, and Pershore more likely above average.

Happy for someone else to do the calculations (I would if I had more time this evening), but eyeballing it, I'd be surprised if the average from those meteograms was less than 0.5C above the model climatology. This is similar to the 1991-2020 per your original post (only 0.1C difference between last 20 years vs 1991-2020) and 1C above 1961-1990. Hence, my central estimate is an average of 1.5C above 1961-1990 over this period.

And in relation to my other thread, I'm now increasingly confident that November will be 11 out of 11 for above 1961-1990 average months this year. It would take a very significant cooldown in the final third, and/or a notable miss from both ECM and GFS about the next two weeks to drag the CET that far down.

On a personal note, after missing too high last month, my guess looks like it is going down the pan again, but in the opposite direction.

 

[Roger J Smith]

It is indeed quite odd Nov 2010 produced epic cold and snow in midst of a long absence of significant November cold. If we look at eleven years 1915-1925, seven out of eleven Novembers were quite cold and wintry. 1915 (2.8), 1918 (5.5), 1919 (3.3), 1921 (4.6), 1922 (5.9), 1923 (3.3) and 1925 (3.6) included several top ten cold Novembers and four not so cold but near average (1916 6.8, 1917 7.8, 1920 6.8 and 1924 7.1). Average in eleven-year interval was only 5.2 C (almost same as 2010). 

Since 1925, only eight years finished below 5.2, 1937 at 5.1, 1942 (4.9), 1952 (4.2), 1965 (4.5), 1985 (3.9),  1988 (5.0), 1993 (4.5) with 2010 at 5.1. Nov 2016 at 5.5 was quite cold also and there are quite a few in that range in the years before 1993.  

We could say that the trend shifted back around 1928, since the cold spell of 1915-25 extended to a fairly cool 5.9 in 1926 and 6.2 in 1927. 

Further back, Nov always had fairly frequent cold turns, the longest absence of averages below 5.2 was 13 consecutive in two intervals, 1660 to 1672, and 1714 to 1726. 1727 was 4.7 and then a very warm interval of eleven years 1728-1738 during which the average was 7.0. As 1727 was not bitterly cold, you could say 1714 to 1738 (25 years) was similar to christmas pudding of 1994 to 2023, 30 consecutive Novembers with no value below 4.7 being the standard now. After those, intervals in the  early 18th century, the longest such interval (no years colder than 5.2) was twelve years (1839 to 1850) but there was a 5.2 in 1841 and only three years were over 7.0 in that interval, so it was not very similar to modern averages close to 7 C. 

1812 to 1816 (five years averaged 4.2 C) flipped to very mild Novembers in 1817, 1818 and 1821, 1822. 

 

[WYorksWeather]

33 minutes ago, Roger J Smith said:

It is indeed quite odd Nov 2010 produced epic cold and snow in midst of a long absence of significant November cold. If we look at eleven years 1915-1925, seven out of eleven Novembers were quite cold and wintry. 1915 (2.8), 1918 (5.5), 1919 (3.3), 1921 (4.6), 1922 (5.9), 1923 (3.3) and 1925 (3.6) included several top ten cold Novembers and four not so cold but near average (1916 6.8, 1917 7.8, 1920 6.8 and 1924 7.1). Average in eleven-year interval was only 5.2 C (almost same as 2010). 

Since 1925, only eight years finished below 5.2, 1937 at 5.1, 1942 (4.9), 1952 (4.2), 1965 (4.5), 1985 (3.9),  1988 (5.0), 1993 (4.5) with 2010 at 5.1. Nov 2016 at 5.5 was quite cold also and there are quite a few in that range in the years before 1993.  

We could say that the trend shifted back around 1928, since the cold spell of 1915-25 extended to a fairly cool 5.9 in 1926 and 6.2 in 1927. 

Further back, Nov always had fairly frequent cold turns, the longest absence of averages below 5.2 was 13 consecutive in two intervals, 1660 to 1672, and 1714 to 1726. 1727 was 4.7 and then a very warm interval of eleven years 1728-1738 during which the average was 7.0. As 1727 was not bitterly cold, you could say 1714 to 1738 (25 years) was similar to christmas pudding of 1994 to 2023, 30 consecutive Novembers with no value below 4.7 being the standard now. After those, intervals in the  early 18th century, the longest such interval (no years colder than 5.2) was twelve years (1839 to 1850) but there was a 5.2 in 1841 and only three years were over 7.0 in that interval, so it was not very similar to modern averages close to 7 C. 

1812 to 1816 (five years averaged 4.2 C) flipped to very mild Novembers in 1817, 1818 and 1821, 1822. 

 

Because why not, I went one step further and converted your analysis to graphical form!

The blue line is a 30-year trailing average (i.e. 1900 means the 30-year average for 1871-1900). The points are the November averages for individual years. Pretty clear that November temperatures now are consistently higher than they have ever been reliably recorded back to the 18th century with an underlying warming trend, though there does appear to be some interdecadal variation. Difficult to say whether this is genuinely cyclical behaviour or just noise.

Since I have the code for this chart now, it might be worth repeating this exercise in December!

[TillyS]

Can anyone tell me what it would need to beat the annual CET maxima record?

My back of the pad calculation is for the remainder of November and then December to be about 2C above average. Does that seem about right?

I think I recall a few years ago that the Met Office announced in mid-December some imminent record warm year and then the weather decide to confound their expectations with a biting cold spell that scuppered it?

[reef]

21 minutes ago, TillyS said:

Can anyone tell me what it would need to beat the annual CET maxima record?

My back of the pad calculation is for the remainder of November and then December to be about 2C above average. Does that seem about right?

I think I recall a few years ago that the Met Office announced in mid-December some imminent record warm year and then the weather decide to confound their expectations with a biting cold spell that scuppered it?

Met Office Hadley Centre Central England Temperature Data Download

WWW.METOFFICE.GOV.UK

1.98C above the 1961-1990 average needed for the warmest year. I think the lowest is safe. That would need 25.46C below average for the remaining days. 

[TillyS]

16 minutes ago, reef said:

Met Office Hadley Centre Central England Temperature Data Download

WWW.METOFFICE.GOV.UK

1.98C above the 1961-1990 average needed for the warmest year. I think the lowest is safe. That would need 25.46C below average for the remaining days. 

[Summer Sun]

9.2c to the 5th

2.8c above the 61 to 90 average
0.5c above the 81 to 10 average

[damianslaw]

I noted the bbc forecasters saying temps a bit below average today, 9-11 degree highs I think are preety close to normal for early November. Perhaps not against running 10 year means. First 10 days of Nov tend to be much milder than average nowadays, same with September. Always associate this time of year with mild atlantic westerlies.

Edited November 6, 2023 by damianslaw

[ItNeverSnowsInWindsor]

Scandinavia seems to be getting colder, just wondering if we could tap into the cold pool at some point this month ?

[Roger J Smith]

We are going to need a very mild DEC to beat 2022 for warmest CET average, after OCT 2023 was 2.4 back in total CET (adding ten monthly averages) and Nov 2022 was 9.2, we are unlikely to see a gain there and possibly a loss, and Dec 2022 was 3.4, so to tie 2022 we would need Nov and Dec to add up to 2.4 more than 12.6, or 15.0. So if Nov were to end up 8.5, it would take a 6.5 Dec. Not sure about second decimal situations involved, or if they calculate with any sort of weighting for number of days, if so, that won't assist 2023 because its two warmest months were 30 days and 2022 had the hot July and August (31 days). 

Chances are probably less than 50-50 that 2023 overtakes 2022 at the end.

As to mean daily maximum, situation is similar (2022 at 15.3 is tops) but a bigger challenge, as total deficit of 2022 so far is 4.7, last year Nov and Dec were 11.9 and 6.6, so 2022 would need to beat that total by 4.7 to tie. I don't see much chance for that one to happen. 

The  years to beat for mean minimum are 2006 and 2014, tied at 7.2; adding up their monthly  means, 2014 is just 0.1 ahead, and 2023 is only a total of 0.8 behind the pace, so to tie 2014 will take 0.8 above means of 5.8 and 2.1 set in 2014, so something like 6 and 3 will get 2023 to first place for mean minimum. It seems quite possible, at least a first on second decimal ahead of both 2014 and 2006.

2023 could also be wettest on record, as of today, a further 335 mm is needed (assuming 45 mm so far in Nov) to surpass 1872. It would take basically record wet Nov and Dec totals, if we get another 155 in Nov (total 200) it would take 180 mm in Dec. Getting to second place (1768) requires 37.6 mm less than those, so about 180 for Nov and 165 for Dec would suffice. Third place 2012 is only about 3 mm less, and 2000 was 12 mm below 2012, so 170 Nov (125 additional from today) and 160 Dec would get 2023 to fourth wettest.

It would be nuts if 2023 scooped all four records but to get to wettest would no doubt take a very mild Dec like 2015 (or 1934 which was 5th wettest Dec and 2nd warmest also); my guess is possibly taking first in mean minimum, second in the other three categories. 

What would it take to fall below second warmest year 2014? It seems entirely possible, if Nov is average at around 7.5 and Dec is cold at around 3.0 I believe 2023 will be no better than third. 

If 2023 was bone dry from today to end of Dec, it would finish at 950 mm or 101st wettest. Every 3 mm of rain we see now gets 2023 past another year, on average, that is the separation in the ranking tables until you get up towards top ten where it widens to 5-6. A normal amount of rain (precip) to end of year would result in a total near 1130 mm which would be close to tenth wettest year. 

[The PIT]

Sunny Sheffield at 8.7C -1.2C below average. Rainfall 41.4mm 46.9% of the monthly average already.

[WYorksWeather]

7 hours ago, damianslaw said:

I noted the bbc forecasters saying temps a bit below average today, 9-11 degree highs I think are preety close to normal for early November. Perhaps not against running 10 year means. First 10 days of Nov tend to be much milder than average nowadays, same with September. Always associate this time of year with mild atlantic westerlies.

It depends on location. I looked at Topcliffe in North Yorkshire and the November average (roughly analogous to mid-November) is 9.9C.

Further south at Kew Gardens though, the average is 11.6C for mid-November.

If you round those both up by 0.5C to account for the fact that we're not quite at mid-November, then it's probably near average in the north, slightly cooler than average for the south. What is holding averages up are mild nights - many places still yet to see their first ground and/or air frosts.

[damianslaw]

1 hour ago, WYorksWeather said:

It depends on location. I looked at Topcliffe in North Yorkshire and the November average (roughly analogous to mid-November) is 9.9C.

Further south at Kew Gardens though, the average is 11.6C for mid-November.

If you round those both up by 0.5C to account for the fact that we're not quite at mid-November, then it's probably near average in the north, slightly cooler than average for the south. What is holding averages up are mild nights - many places still yet to see their first ground and/or air frosts.

Ok, yes average maxes this time of year still in double digits for majority of UK. I think average maxes in late March are cooler. We had a few light frosts mid October.

Might be some first frosts early hours of Sat and possibly Sunday.

[LetItSnow!]

On 05/11/2023 at 21:03, Roger J Smith said:

EWP now around 40 mm and GFS indicates heavy rainfalls in parts of northwest England and Wales, but 20-30 mm additional in parts of eastern and southern England, so a blend looks like 50 mm additional to 21st, 90 mm total by then.

CET looks to stay rather mild with two peaks near record highs but near average other days, will speculate that we stay around 9 C well into the month with oscillations in the range 9 to 9.5. Any later cold spell will need to be quite powerful to serve the interests below 8.0 end of Nov. 

Current GFS 16-day charts do not look as though cold air will be advancing, and a bland westerly flow is indicated then, after some windy days around 17-18 Nov. 

Where are we looking at in terms of the overall autumn? A mild November with a record-breaking September and warm October would put us in line for a record warm autumn or somewhere in the top 5? Depends on where the second-half of the month takes us.

[Roger J Smith]

2 hours ago, LetItSnow! said:

Where are we looking at in terms of the overall autumn? A mild November with a record-breaking September and warm October would put us in line for a record warm autumn or somewhere in the top 5? Depends on where the second-half of the month takes us.

Top 15 CET averages for autumn, and exact data to reveal 2023 options to tie ... 

Rank ____ Year _____ Avg ____ SEP _ OCT _ NOV ____ 2023 to tie

_ 01 ____ 2006 _____ 12.6 ____ 16.9 _ 12.9 _ 8.0 ____ 8.7

_ 02 ____ 2011 _____ 12.4 ____ 15.1 _ 12.5 _ 9.5 ____ 8.0

_ 03 ____ 2022 _____ 12.1 ____ 14.4 _ 12.8 _ 9.2 ____ 7.3

_ 04 ____ 2014 _____ 12.0 ____ 15.1 _ 12.3 _ 8.5 ____ 6.8

_t05 ____ 1731 _____ 11.8 ____ 15.3 _ 12.3 _ 7.8 ____ 6.3

_t05 ____ 1730 _____ 11.8 ____ 15.3 _ 10.9 _ 9.2 ____ 6.3

_ 07 ____ 2021 _____ 11.7 ____ 16.0 _ 12.0 _ 7.2 ____ 6.1

_t08 ____ 1818 _____ 11.6 ____ 13.3 _ 12.0 _ 9.5 ____ 5.7

_t08 ____ 1729 _____ 11.6 ____ 16.6 _ 10.1 _ 8.1 ____ 5.7

_t10 ____ 1959 _____ 11.5 ____ 14.9 _ 12.6 _ 7.1 ____ 5.5

_t10 ____ 1949 _____ 11.5 ____ 16.3 _ 11.7 _ 6.6 ____ 5.5

_ 12 ____ 2005 _____ 11.5*____ 15.2 _ 13.0 _ 6.1 ____ 5.3

_ 13 ____ 2009 _____ 11.4 ____ 14.3 _ 11.4 _ 8.6 ____ 5.3

_t14 ____ 2001 _____ 11.4 ____ 13.4 _ 13.2 _ 7.5 ____ 5.0

_t14 ____ 1978 _____ 11.4 ____ 14.1 _ 11.7 _ 8.3 ____ 5.0

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

(note: in above table, order is from metoffice table, ties are established by me if two-decimal average is a tie (or if total of three autumn months is same)). 

* ... even so, their calculations seem to be based on some kind of weighting, for example, 2005 works out to 11.43 in the equal weight system used in CET legacy with a two-decimal table. 2005 is actually tied with 2009 in terms of total, but as their system came to different one-decimal values, I did not show a tie for them. 

Notice three in a row in list 1729-31 and 2023 will repeat this feat. 2020 is listed as 30th (11.0), one of six and the last of them to appear. 

Interesting to see that warmest Sep and Oct are in list but warmest Nov (1994) was part of a 10.9 average and four years are listed 31st to 35th (will become 32nd to 36th after 2023 slides into top ten). 1994 is given as second last of those four so appears in 34th about to be 35th. 

[ItNeverSnowsInWindsor]

Looks like GFS are showing a very mild spell in two weeks from the latest two runs now.

Would need something substantially cold in the final week to offset this now.

Most likely finish well in the 8’s.

[TillyS]

6 hours ago, prolongedSnowLover said:

Looks like GFS are showing a very mild spell in two weeks from the latest two runs now.

Would need something substantially cold in the final week to offset this now.

Most likely finish well in the 8’s.

The ECMWF would be a LOT colder though with the high pressure, no? It is very different from the GFS. There’s some intense cold knocking on our door here:

 

[Summer Sun]

9.2c to the 6th

2.7c above the 61 to 90 average
0.6c above the 81 to 10 average