January 2024 CET and E.W.P. forecast contests

[WYorksWeather]

1 hour ago, LetItSnow! said:

The guess was not actually mine and was Roger’s who is a respected poster and quite good with his predictions. I anticipate low 5s but upper 4s into the 5s a safe bet because it would take something remarkable to get into the 6s, which I suppose could happen if the build of pressure fails and we remained under blow torch south-westerlies for the rest of the month. I’m sure someone can make a calculation of what would be required to reach 6.0C. Conversely, if heights do build and we manage a colder / more average end it could stall, hence why I think upper 4s to low 5s could be a good bet, but also a fair chance of higher. I am very aware of the nature of forecasting being tricky. A lot of us thought February 2021 could have been sub zero around the 8th of that month but then things flipped, not unlike now with record cold over America shunting the pattern into unfavourable conditions for cold, squeezing the heights down into Europe and up come the south-westerlies. Nonetheless, Interesting times! I wonder what February will bring. Could still be in the game for a pattern reset come end of the month.  

I've been working it out based on where we are by the 20th. If we assume 4.0C, after two days near or sub-zero, then Friday near normal, and Saturday relatively mild, then you'd need the following averages for the 11 remaining days:

To finish at 4.5C: 5.5C

To finish at 5.0C: 6.9C

To finish at 5.5C: 8.3C

To finish at 6.0C: 9.7C

Note that I've ignored rounding here, so 4.0C is assumed to be exactly 4.0C, and finishes are taken to be strictly greater than the target value, i.e. no allowance made for the fact that 5.46C rounds up to 5.5C. So in reality there's a bit more wiggle room.

In terms of how sensitive this is, each 0.1C change in where we are by the 20th moves the targets by just under 0.2C. Probably worth coming back to review these calculations then when I can substitute in the correct value for the position as at the 20th.

 

[The PIT]

Sunny Sheffield down to 3.7C -1.0C below average. Rainfall unchanged

[Roger J Smith]

Well, today's GFS run was not as cold at end of January, but CET is dropping down steadily so I would take all of the above from a point closer to 3.5 by 20 Jan (possibly). I would say 5.2 based on today's guidance. But it could keep on changing if we get into the often-seen GFS day to day flip flop routine. Just looked in my CET data base for all cases where January was above 7 at any point in first half, was below 4.2 at any point in period 15-20 Jan, and was at or above 4.8 at end. The search yielded these cases listed in reverse chronological order:

 

JANUARY ______ high point early _____ below 4 15-20 ______ outcome ____ FEB CET 

1981 ________ 7.6 (3rd) ____________ 4.1 16th-19th ____________ 4.8 ________ 3.0 

1943 ________ 7.6 (1st) ____________ 1.6 (9th), 3.1 16th ________ 4.9 ________ 6.1

1863 ________ 7.8 (1st) ____________ 3.6 17th __________________ 4.9 ________ 5.8

 

Very few analogues found, so I broadened the criteria to include the following "nearly" and well correlated non qualifiers: 

JANUARY ______ high point early _____ below 4 15-20 ______ outcome ____ FEB CET 

2003 ________ 7.0 (2nd) ___________ 1.7 11th-12th, 3.0 16th__4.4 (4.7 29th)_ 3.9

1973 ________ 6.2 (5th) ____________ 3.5 20th-21st ____________ 4.5 ________ 4.3

1960 ________ 9.5 (1st) _____________2.8 17th-18th ____________3.8 ________ 4.1

1926 ________ 7.3 (6th) ____________ 3.7 19th -23rd ___________ 4.6 ________ 6.8

1924 ________ 7.0 (2nd) ____________2.3 10th, 3.6 17th ________4.7 ________ 3.3

1903 ________ 6.1 (7th) ____________ 2.8 19th-21st ____________ 4.2 ________ 7.1

1840 ________ 9.3 (1st) ____________ 1.3 12th-13th ____________ 4.1 ________ 3.6

1824 ________ 8.1 (1st) ____________ 3.0 17th-18th ____________ 4.3 ________ 4.7

1817 ________ 7.0 (1st) ____________ 2.4 16th __________________4.5 ________ 6.4

1797 _________7.6 (1st) _____________ below 2.2 11-19 ________ 3.5 ________ 4.6

Also, 1982 while colder went 6.9 (5th), -0.3 15th-16th, ended 2.7________ 4.8

2016 a fainter signal, 6.4 (5th-7th), 4.2 on 21st, and ended on 5.5 _______5.1

2018 a fainter signal, 6.7 (4th), 4.6 12th-13th, 20th-22nd, ended 5.3_____3.1

 

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

It would appear that this relatively rare type of January is often followed by an average to mild February.

1926 and 2003 were very close to qualifying, outcomes were somewhat anemic compared to the three years that did qualify. It appears that 1863 could be the closest analogue but 1926 looks very similar. 

I also looked at following Febs in detail and noticed a strong tendency for one cold spell around mid-month to late February, same general idea as January, mild to colder and often back to mild but not always. 1840 did have a sustained cold second half, subzero CET values around 18-22 Feb. 1903 registered several near-record highs, no cold spell, and ended with a severe windstorm (27 Feb). 1960 was generally a cold Feb but ended with two very mild days, setting record of 12.0 on leap year day. 

 

[WYorksWeather]

2 hours ago, Roger J Smith said:

Well, today's GFS run was not as cold at end of January, but CET is dropping down steadily so I would take all of the above from a point closer to 3.5 by 20 Jan (possibly). I would say 5.2 based on today's guidance. But it could keep on changing if we get into the often-seen GFS day to day flip flop routine. Just looked in my CET data base for all cases where January was above 7 at any point in first half, was below 4.2 at any point in period 15-20 Jan, and was at or above 4.8 at end. The search yielded these cases listed in reverse chronological order:

 

JANUARY ______ high point early _____ below 4 15-20 ______ outcome ____ FEB CET 

1981 ________ 7.6 (3rd) ____________ 4.1 16th-19th ____________ 4.8 ________ 3.0 

1943 ________ 7.6 (1st) ____________ 1.6 (9th), 3.1 16th ________ 4.9 ________ 6.1

1863 ________ 7.8 (1st) ____________ 3.6 17th __________________ 4.9 ________ 5.8

 

Very few analogues found, so I broadened the criteria to include the following "nearly" and well correlated non qualifiers: 

JANUARY ______ high point early _____ below 4 15-20 ______ outcome ____ FEB CET 

2003 ________ 7.0 (2nd) ___________ 1.7 11th-12th, 3.0 16th__4.4 (4.7 29th)_ 3.9

1973 ________ 6.2 (5th) ____________ 3.5 20th-21st ____________ 4.5 ________ 4.3

1960 ________ 9.5 (1st) _____________2.8 17th-18th ____________3.8 ________ 4.1

1926 ________ 7.3 (6th) ____________ 3.7 19th -23rd ___________ 4.6 ________ 6.8

1924 ________ 7.0 (2nd) ____________2.3 10th, 3.6 17th ________4.7 ________ 3.3

1903 ________ 6.1 (7th) ____________ 2.8 19th-21st ____________ 4.2 ________ 7.1

1840 ________ 9.3 (1st) ____________ 1.3 12th-13th ____________ 4.1 ________ 3.6

1824 ________ 8.1 (1st) ____________ 3.0 17th-18th ____________ 4.3 ________ 4.7

1817 ________ 7.0 (1st) ____________ 2.4 16th __________________4.5 ________ 6.4

1797 _________7.6 (1st) _____________ below 2.2 11-19 ________ 3.5 ________ 4.6

Also, 1982 while colder went 6.9 (5th), -0.3 15th-16th, ended 2.7________ 4.8

2016 a fainter signal, 6.4 (5th-7th), 4.2 on 21st, and ended on 5.5 _______5.1

2018 a fainter signal, 6.7 (4th), 4.6 12th-13th, 20th-22nd, ended 5.3_____3.1

 

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

It would appear that this relatively rare type of January is often followed by an average to mild February.

1926 and 2003 were very close to qualifying, outcomes were somewhat anemic compared to the three years that did qualify. It appears that 1863 could be the closest analogue but 1926 looks very similar. 

I also looked at following Febs in detail and noticed a strong tendency for one cold spell around mid-month to late February, same general idea as January, mild to colder and often back to mild but not always. 1840 did have a sustained cold second half, subzero CET values around 18-22 Feb. 1903 registered several near-record highs, no cold spell, and ended with a severe windstorm (27 Feb). 1960 was generally a cold Feb but ended with two very mild days, setting record of 12.0 on leap year day. 

 

For completeness, if we assume 3.5C to the 20th (note that by this I mean the figure reported on the 21st, for 1st-20th):

To finish at 4.5C: 6.4C

To finish at 5.0C: 7.8C

To finish at 5.5C: 9.2C

To finish at 6.0C: 10.6C

As stated, the figure on the 20th will be very important. I think 3.5C to 4.0C is the envelope, so we'll see where it lands, then I'll post some revised figures.

[TillyS]

Well, a bitterly cold night in the central England area, with another to come, so I think this is going to take quite a hit between now and Saturday. The GFS underestimated the minima. The CET might drop to not far off 3C by the 20th.

After that? Rising for at least a week, sometimes substantially, and probably rising for the whole of the final third of the month. 

Edit. In fact, looking at the overnight outputs from the UKMO and ECM we may be looking at significant rises next week. The BBC Meteo forecast spoke of, “incredibly mild.” Not sure if it will be enough to take it much above 5C but I’d rule little out at the moment.

Edited January 18 by TillyS

[damianslaw]

2 hours ago, TillyS said:

Well, a bitterly cold night in the central England area, with another to come, so I think this is going to take quite a hit between now and Saturday. The GFS underestimated the minima. The CET might drop to not far off 3C by the 20th.

After that? Rising for at least a week, sometimes substantially, and probably rising for the whole of the final third of the month. 

Edit. In fact, looking at the overnight outputs from the UKMO and ECM we may be looking at significant rises next week. The BBC Meteo forecast spoke of, “incredibly mild.” Not sure if it will be enough to take it much above 5C but I’d rule little out at the moment.

A very notable difference 13-20 Jan compared to 21-28 Jan, will be interesting to compare the contrast. 

[Daniel*]

Expect a notably low daily mean for today. Pershore -9.7C for example, I can’t see high climbing much above freezing.  

Edited January 18 by Daniel*

[Summer Sun]

3.6c to the 16th

0.2c below the 61 to 90 average
0.8c below the 81 to 10 average

[kold weather]

2 hours ago, Daniel* said:

Expect a notably low daily mean for today. Pershore -9.7C for example, I can’t see high climbing much above freezing.  

Should be comfortably subzero today.

Could well have a CET near 2.5c by 20th (probably between 2.5-3c)  , which would require probably the most exceptional mild spell ever seen in January to get upto 6c+.

With that being said, we are going to have some very mild days coming up so we should still end up comfortably above the 61-90 mean. The 91-20 mean will be tighter if the GFS is correct with a more average final few days,

Edited January 18 by kold weather

[BlueSkies_do_I_see]

The weather from Sunday onwards is looking incredibly mild 21-31st is the daily max reaching 10C + every day, peaking at 14C on the 23rd for my location in Coventry.

If that came off, we couldn't be far off record high 2nd half of January temperatures. despite this current cold snap? 

[kold weather]

50 minutes ago, BlueSkies_do_I_see said:

The weather from Sunday onwards is looking incredibly mild 21-31st is the daily max reaching 10C + every day, peaking at 14C on the 23rd for my location in Coventry.

If that came off, we couldn't be far off record high 2nd half of January temperatures. despite this current cold snap? 

This cold spell will 99% kill any chances of breaking a record for the warmest 2nd half of January, I will leave the tiny chance just because this a record warm world and you can't ever be certain of these things. With that being said to reach 2002 2nd half of Jan (which was exceptionally mild) would require the last 14 days of this month to now reach 8.8c as an average, and obviously the next two-three days will be dramatically below that, so the final figure will be north of 10c vs 2002.

The warmest 2nd half I can see just through eye appears to be 1846, with a 16-31st coming in at 8.3c. That would require a 2 week mean of 9.5c from todays figure onward. By Sunday we'd require something like a top 5 all time Jan CET day level of warmth to match the 2nd half of 1846, 11 days is a row....

I agree though it does look very mild from Sun until at least Wed-Thurs, beyond that considerably more uncertainty. We may well be see a date record fall on Tuesday, though 1843 has an exceptionally high value of 11,6c to beat which won't be easy given that number is very high up the all time rankings.

Edited January 18 by kold weather

[Daniel*]

2 hours ago, kold weather said:

Should be comfortably subzero today.

Could well have a CET near 2.5c by 20th (probably between 2.5-3c)  , which would require probably the most exceptional mild spell ever seen in January to get upto 6c+.

With that being said, we are going to have some very mild days coming up so we should still end up comfortably above the 61-90 mean. The 91-20 mean will be tighter if the GFS is correct with a more average final few days,

Comfortably subzero yes, we should be -2 to -2.5C for the daily mean. Using GFS, you are bound to underestimate the very cold nights in particular.

Rothamstad 1.8C high -5.1C low = -1.65

Pershore 4C high -9.7c Low = -2.85

Stonyhurst estimating using local station 1c high -7C low = -3C

I think we could drop 0.4C... taking us to 3.2C if not likely 3.3C for todays values.

Edited January 18 by Daniel*

[LetItSnow!]

A look at the GFS and GEM shows the idea of heights building and potentially setting up Scandinavian heights into early February. Where this month exactly lands is entirely dependent on whether that pressure rise fails to establish or not. I’d say it’s best to calculate your predictions for up to the 25th as it could go anywhere after that. If we don’t see the pressure raise substantially or it ends up too south and we stay at the behest of mild south-westerly winds, more likely to be in 5s - but if we do see temperatures fall close to average in the closing days, perhaps even a touch below average, then perhaps the 4s will be a closer bet.

Regardless of what you think, January 2024 will be remembered as a month with great variability. We’ve seen heavy rain, we’re about to see very strong gales and also exceptionally mild temperatures, but we’ve also seen snow in some places and some bitter frosts. January 2024 has seen a bit of it all. Not too dissimilar to January 2003 and it may end up with a similar CET. It’s all down to where we end up come the 27th. I’d caution anyone who’s certain every day of the month after the 20th will be very mild as there could be some surprises afoot. We’ll see. 

[damianslaw]

35 minutes ago, LetItSnow! said:

A look at the GFS and GEM shows the idea of heights building and potentially setting up Scandinavian heights into early February. Where this month exactly lands is entirely dependent on whether that pressure rise fails to establish or not. I’d say it’s best to calculate your predictions for up to the 25th as it could go anywhere after that. If we don’t see the pressure raise substantially or it ends up too south and we stay at the behest of mild south-westerly winds, more likely to be in 5s - but if we do see temperatures fall close to average in the closing days, perhaps even a touch below average, then perhaps the 4s will be a closer bet.

Regardless of what you think, January 2024 will be remembered as a month with great variability. We’ve seen heavy rain, we’re about to see very strong gales and also exceptionally mild temperatures, but we’ve also seen snow in some places and some bitter frosts. January 2024 has seen a bit of it all. Not too dissimilar to January 2003 and it may end up with a similar CET. It’s all down to where we end up come the 27th. I’d caution anyone who’s certain every day of the month after the 20th will be very mild as there could be some surprises afoot. We’ll see. 

One of those months that on paper from the CET value is not reflective of what happened i.e..a very mild start, followed by quite a cold 2 week spell overall, will be good to confirm the mean for 6-20 Jan.. and then a possible exceptionally mild last third or something just mild as it could turn near average last few days. 

A varied January.

[WYorksWeather]

3 hours ago, kold weather said:

Should be comfortably subzero today.

Could well have a CET near 2.5c by 20th (probably between 2.5-3c)  , which would require probably the most exceptional mild spell ever seen in January to get upto 6c+.

With that being said, we are going to have some very mild days coming up so we should still end up comfortably above the 61-90 mean. The 91-20 mean will be tighter if the GFS is correct with a more average final few days,

My guess of 4.0C by the 20th now looks ridiculously high, I'll give you that. It'll be sufficient to wipe out the possibility of a 6.0C finish. I still think 5s is much more likely than 4s though. I will recalculate the required values for the different thresholds on the 20th.

[TillyS]

4 hours ago, kold weather said:

Should be comfortably subzero today.

Could well have a CET near 2.5c by 20th (probably between 2.5-3c) 

2.5C? 

If was 3.6C to the 17th, that only leaves the 18th in the very cold range. The 19th cold, but not quite as cold. The 20th it starts going upwards.

To get to 2.5C from here would surely require a mean CET over those two blank days of -6C?!

What am I missing here?

I’d say around 3C to the 19th inclusive.

[Roger J Smith]

A minor point, but it partly depends on whether you look at second half of any 31-day month as being 16th-31st or 17th-31st (summer blizzard and I discussed this once, we both favoured 17-31 but some prefer 16-31). With 16th Jan already in books as a cold day, it would reduce second half of January average by about 0.4 if included. I will ask my data base to spit out top averages for 16-31 and 17-31 Jan. Just on my way out so it will be posted a few hours from now. 

[kold weather]

9 minutes ago, TillyS said:

2.5C? 

If was 3.6C to the 17th, that only leaves the 18th in the very cold range. The 19th cold, but not quite as cold. The 20th it starts going upwards.

To get to 2.5C from here would surely require a mean CET over those two blank days of -6C?!

What am I missing here?

I’d say around 3C to the 19th inclusive.

Nothing, my mistake because SS said 3.6 to the 16th, but that figure is actually upto the 17th as you rightly say.

Could well still get down about 3c though as you say.

I suspect somewhere between 4.5-5.5c is looking like the eventual landing spot, towards the cooler end if we do see a bend back towards average or even a little below like the latest set of runs, or closer to 5.5c if we blow torch through to the end.

Pretty likely still we end up with an above average 61-90 month, though a very cold end could run it close.

[TillyS]

Oh phew. Sorry, I really thought I was mistaken about it.

On a separate but related point, I’m not convinced about some ‘flip’ coming, at least not this month. Looks to me like the kind of synoptics which set in for a fortnight before blowing out, if they do. By the time the Atlantic blast begins on Sunday I reckon we’ve got 10 days of CET rises.

An interesting month whatever happens, with lots of contrast.

[WYorksWeather]

Right, so let's think this one through. Suppose we get a CET around -3C for the 18th, 0C for the 19th, and 4C for the 20th (each of these probably at the lower end for safety). We're currently on 3.6C, so I get 3.1C as the lowest possibility for where we might be. At the higher end would be something like -2C for today, 2C tomorrow, 6C on Saturday, which would give us 3.4C. This is ignoring rounding, so our true landing zone now is probably in the 3.0C to 3.5C range.

Definitely pushes the 6C off the table if those numbers are anything like right (I hadn't quite expected such a cold couple of days, expected CET near zero but not comfortably negative). Upper 5s is probably more difficult than it was as well, but still possible if we stay blowtorch SW to the end. Probably lower 5s is now a good bet. Upper 4s I think would require a firmer signal for something colder in the last two or three days.

[Roger J Smith]

Warmest average CET 16-31, 17-31 and 21-31 January

Years are ranked for each interval, 17-31 Jan is my preferred version of "second half January." I added 21-31 Jan because it is likely to be a generally mild period. 

Added on 1 Feb _ 2024 average was 7.58 for 21-31 ... 9th highest average. All in table 1918 and down lose one spot as a result. Averages for 16-31 and 17-31 were outside top thirty at 5.33 and 5.67.

 

Rank _ YEAR __ 16-31 Jan __ [][][] __Rank_ YEAR_ 17-31 Jan __ [][] __ Rank _YEAR_ 21-31 Jan

_01 ___ 1846 __ 8.34 _______ [][][] _ 01 ___ 1846 __ 8.41 _______[][] __ 01 ___ 1846 __ 8.88

_02 ___ 1804 __ 8.19 _______ [][][] _ 02 ___ 1804 __ 8.15 _______[][] __ 02 ___ 2002 __ 8.47

_03 ___ 1921 __ 7.84 _______ [][][] _ 03 ___ 1921 __ 8.04 _______[][] __ 03 ___ 1921 __ 8.23

_04 ___ 1796 __ 7.73 _______ [][][] _ 04 ___ 2002 __ 7.87 _______[][] __ 04 ___ 1804 __ 8.17 

_05 ___ 2002 __ 7.71 _______ [][][] _ 05 ___ 1828 __ 7.77 _______[][] __ 05 ___ 1969 __ 7.94

_06 ___ 1834 __ 7.44 _______ [][][] _ 06 ___ 1898 __ 7.67 _______[][] __ 06 ___ 2016 __ 7.72

_07 ___ 2008 __ 7.41 _______ [][][] _ 07 ___ 1796 __ 7.59 _______[][] __ 07 ___ 1834 __ 7.68

_08 ___ 1828 __ 7.40 _______ [][][] _ 08 ___ 2008 __ 7.56 _______[][] __ 08 ___ 1898 __ 7.64

_09 ___ 1898 __ 7.36 _______ [][][] _ 09t___ 1834 __ 7.36 _______[][] __ 09 ___ 1918 __ 7.43

_10 ___ 1916 __ 7.33 _______ [][][] _ 09t___ 1916 __ 7.36 _______[][] __ 10 ___ 1796 __ 7.36 

_11 ___ 1993 __ 6.88  ______ [][][] _ 11 ___ 1969 __ 7.03 _______ [][] __ 11 ___ 1967 __ 7.25

_12 ___ 1990 __ 6.78_______ [][][] _ 12 ___ 1967 __ 7.01 _______ [][] __ 12 ___ 1843 __ 7.14^ 

_13t___ 1967 __ 6.73 _______[][][] _ 13 ___ 1918 __ 6.87 _______ [][] __ 13 ___ 1916 __ 7.13 

_13t___ 1969 __ 6.73 _______[][][] _ 14 ___ 1943 __ 6.79 _______ [][] __ 14 ___ 1943 __ 7.10

_15 ___ 1943 __ 6.70 ______[][][] _ 15 ___ 1817 __ 6.69 ______ [][] __ 15 ___ 1828 __ 7.08

_16 ___ 1968 __ 6.59 _______ [][][] _ 16 ___ 1993 __ 6.66 _______ [][] __ 16 ___ 2008 __ 7.04

_17 ___ 1938 __ 6.53 _______ [][][] _ 17 ___ 1990 __ 6.51 _______ [][] __ 17 ___ 1944 __ 6.97

_18 ___ 1866 __ 6.51 _______ [][][] _ 18 ___ 1968 __ 6.48 _______ [][] __ 18 ___ 1817 __ 6.92

_19 ___ 1918 __ 6.45 _______ [][][] _ 19 ___ 1866 __ 6.46 _______ [][] __ 19 ___ 1782 __ 6.89^

_20 ___ 1817 __ 6.39 _______ [][][] _ 20 ___ 1944 __ 6.44 _______ [][] __ 20 ___ 1994 __ 6.75

_21t___ 1854 __ 6.35 _______ [][][] _ 21 ___ 1938 __ 6.43 _______ [][] __ 21 ___ 1903 __ 6.72^

_21t___ 1974 __ 6.35 _______ [][][] _ 22 ___ 1854  __ 6.41 _______[][] __ 22 ___ 1863 __ 6.68

_23 ___ 1875 __ 6.34 _______ [][][] _ 23t___ 1884 __ 6.35 _______ [][] __ 23 ___ 2018 __ 6.65

_24 ___ 1920 __ 6.32 _______ [][][] _ 23t___ 1974 __ 6.35 _______ [][] __ 24 ___ 1938 __ 6.59

_25 ___ 1884 __ 6.31 ______ [][][] _ 25 ___ 1840 __ 6.28 ______ [][] __ 25 ___1993 __ 6.55

_26 ___ 1840 __ 6.23 ______ [][][] _ 26 ___ 1863 __ 6.25 ______ [][] __ 26 ___ 1840 __ 6.51

_27 ___ 1859 __ 6.14 ______ [][][] _ 27t___ 1859 __ 6.23 ______ [][] __ 27 ___ 1923 __ 6.50

_28 ___ 1844 __ 6.12 _______ [][][] _ 27t ___ 1875 __ 6.23 _______ [][] __ 28 ___ 1884 __ 6.48 

_29 ___ 1923 __ 6.03 _______ [][][] _ 29 ___ 1843 __ 6.15 ______ [][] __ 29 ___ 1990 __ 6.48

_30t___ 1863,2003_ 6.02 __ [][][] _ 30 ___ 1920 __ 6.14 _______ [][] __ 30 ____ 1975 __ 6.45

 

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

Table entries above not in top 30 for 21-31 Jan, also non-table entries in t32 plus second half averages

rank 31 for 21-31 _ 1854 (6.42) in table

rank t32 for 21-31_ 1824 (6.30) 5.19, 5.45

rank t32 for 21-31 _1983 (6.30) 6.01, 5.77

rank 34 for 21-31 __ 1866 (6.03) in table

rank 38 for 21-31 __ 1859 (5.91) in table

rank not top 50 __ 1920 (5.53) in table

rank not top 50 __ 1875 (5.44) in table

2007 did not qualify for table at all, values were 5.92, 5.79, 4.55

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

^ Values for ranked 21st-31th Jan (above) not qualifying for top ten second half January:

Ranked _____ Average 16-31 ___ Ranked _____ Average 17-31

_03 21-31 ___ 2016 __ 5.69 ___ [][] _ 03 21-31 ___ 2016 __ 6.05 __

_12 21-31 ___ 1843 __ 5.92 ___ [][] _ 12 21-31 ___ 1843 __ 6.15 (in table) 

_19 21-31 ___ 1782 __ 4.26 ___ [][] _ 19 21-31 ___ 1782 __ 4.48 __

_20 21-31 ___ 1994 __ 5.69 ___ [][] _ 17 21-31 ___ 1994 __ 5.91 __

_21 21-31 ___ 1903 __ 4.84 ___ [][] _ 15 21-31 ___ 1903 __ 5.27 __

_23 21-31 ___ 2018 __ 5.76 ___ [][] _ 20 21-31 ___ 2018 __ 5.85 __

 

_30 21-31 ___ 1923 __ 6.03 __ [][] _ 30 21-31 ___ 1923 __ 6.01 

_30 21-31 ___ 1975 __ 5.71 __ [][] _ 30 21-31 ___ 1975 __ 5.77

 

2003 values 6.02 5.97 5.86

 

 

Edited February 1 by Roger J Smith

[TillyS]

10 hours ago, WYorksWeather said:

Right, so let's think this one through. Suppose we get a CET around -3C for the 18th, 0C for the 19th, and 4C for the 20th (each of these probably at the lower end for safety). We're currently on 3.6C, so I get 3.1C as the lowest possibility for where we might be. At the higher end would be something like -2C for today, 2C tomorrow, 6C on Saturday, which would give us 3.4C. This is ignoring rounding, so our true landing zone now is probably in the 3.0C to 3.5C range.

Definitely pushes the 6C off the table if those numbers are anything like right (I hadn't quite expected such a cold couple of days, expected CET near zero but not comfortably negative). Upper 5s is probably more difficult than it was as well, but still possible if we stay blowtorch SW to the end. Probably lower 5s is now a good bet. Upper 4s I think would require a firmer signal for something colder in the last two or three days.

Great post although I’m uncomfortable about saying ‘definitely’ not 6C. It would take something remarkable but the UK weather has the capacity to confound, especially with upward-spiralling temperatures. More realistically, it may get as high as 5.5C but it all depends, really, on those night time minima from tomorrow.

This last night 18/19th was bitterly cold in the south again but not so much in the north-west, although Hawarden dipped to around -1.5C before the uplift. Temps are rising as the wind switches direction to the west / south-west. Then it really is going to get very mild:

[Midlands Ice Age]

8 hours ago, Roger J Smith said:

Warmest average CET 16-31, 17-31 and 21-31 January

Years are ranked for each interval, 17-31 Jan is my preferred version of "second half January." I added 21-31 Jan because it is likely to be a generally mild period. 

 

Rank _ YEAR __ 16-31 Jan __ [][][] __Rank_ YEAR_ 17-31 Jan __ [][] __ Rank _YEAR_ 21-31 Jan

_01 ___ 1846 __ 8.34 _______ [][][] _ 01 ___ 1846 __ 8.41 _______[][] __ 01 ___ 1846 __ 8.88

_02 ___ 1804 __ 8.19 _______ [][][] _ 02 ___ 1804 __ 8.15 _______[][] __ 02 ___ 2002 __ 8.47

_03 ___ 1921 __ 7.84 _______ [][][] _ 03 ___ 1921 __ 8.04 _______[][] __ 03 ___ 1921 __ 8.23

_04 ___ 1796 __ 7.73 _______ [][][] _ 04 ___ 2002 __ 7.87 _______[][] __ 04 ___ 1804 __ 8.17 

_05 ___ 2002 __ 7.71 _______ [][][] _ 05 ___ 1828 __ 7.77 _______[][] __ 05 ___ 1969 __ 7.94

_06 ___ 1834 __ 7.44 _______ [][][] _ 06 ___ 1898 __ 7.67 _______[][] __ 06 ___ 2016 __ 7.72

_07 ___ 2008 __ 7.41 _______ [][][] _ 07 ___ 1796 __ 7.59 _______[][] __ 07 ___ 1834 __ 7.68

_08 ___ 1828 __ 7.40 _______ [][][] _ 08 ___ 2008 __ 7.56 _______[][] __ 08 ___ 1898 __ 7.64

_09 ___ 1898 __ 7.36 _______ [][][] _ 09t___ 1834 __ 7.36 _______[][] __ 09 ___ 1918 __ 7.43

_10 ___ 1916 __ 7.33 _______ [][][] _ 09t___ 1916 __ 7.36 _______[][] __ 10 ___ 1796 __ 7.36 

_11 ___ 1993 __ 6.88  ______ [][][] _ 11 ___ 1969 __ 7.03 _______ [][] __ 11 ___ 1967 __ 7.25

_12 ___ 1990 __ 6.78_______ [][][] _ 12 ___ 1967 __ 7.01 _______ [][] __ 12 ___ 1843 __ 7.14^ 

_13t___ 1967 __ 6.73 _______[][][] _ 13 ___ 1918 __ 6.87 _______ [][] __ 13 ___ 1916 __ 7.13 

_13t___ 1969 __ 6.73 _______[][][] _ 14 ___ 1943 __ 6.79 _______ [][] __ 14 ___ 1943 __ 7.10

_15 ___ 1943 __ 6.70 ______[][][] _ 15 ___ 1817 __ 6.69 ______ [][] __ 15 ___ 1828 __ 7.08

_16 ___ 1968 __ 6.59 _______ [][][] _ 16 ___ 1993 __ 6.66 _______ [][] __ 16 ___ 2008 __ 7.04

_17 ___ 1938 __ 6.53 _______ [][][] _ 17 ___ 1990 __ 6.51 _______ [][] __ 17 ___ 1944 __ 6.97

_18 ___ 1866 __ 6.51 _______ [][][] _ 18 ___ 1968 __ 6.48 _______ [][] __ 18 ___ 1817 __ 6.92

_19 ___ 1918 __ 6.45 _______ [][][] _ 19 ___ 1866 __ 6.46 _______ [][] __ 19 ___ 1782 __ 6.89^

_20 ___ 1817 __ 6.39 _______ [][][] _ 20 ___ 1944 __ 6.44 _______ [][] __ 20 ___ 1994 __ 6.75

_21t___ 1854 __ 6.35 _______ [][][] _ 21 ___ 1938 __ 6.43 _______ [][] __ 21 ___ 1903 __ 6.72^

_21t___ 1974 __ 6.35 _______ [][][] _ 22 ___ 1854  __ 6.41 _______[][] __ 22 ___ 1863 __ 6.68

_23 ___ 1875 __ 6.34 _______ [][][] _ 23t___ 1884 __ 6.35 _______ [][] __ 23 ___ 2018 __ 6.65

_24 ___ 1920 __ 6.32 _______ [][][] _ 23t___ 1974 __ 6.35 _______ [][] __ 24 ___ 1938 __ 6.59

_25 ___ 1884 __ 6.31 ______ [][][] _ 25 ___ 1840 __ 6.28 ______ [][] __ 25 ___1993 __ 6.55

_26 ___ 1840 __ 6.23 ______ [][][] _ 26 ___ 1863 __ 6.25 ______ [][] __ 26 ___ 1840 __ 6.51

_27 ___ 1859 __ 6.14 ______ [][][] _ 27t___ 1859 __ 6.23 ______ [][] __ 27 ___ 1923 __ 6.50

_28 ___ 1844 __ 6.12 _______ [][][] _ 27t ___ 1875 __ 6.23 _______ [][] __ 28 ___ 1884 __ 6.48 

_29 ___ 1923 __ 6.03 _______ [][][] _ 29 ___ 1843 __ 6.15 ______ [][] __ 29 ___ 1990 __ 6.48

_30t___ 1863,2003_ 6.02 __ [][][] _ 30 ___ 1920 __ 6.14 _______ [][] __ 30t____ 1975 __ 6.45

 

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

Table entries above not in top 30 for 21-31 Jan, also non-table entries in t32 plus second half averages

rank 31 for 21-31 _ 1854 (6.42) in table

rank t32 for 21-31_ 1824 (6.30) 5.19, 5.45

rank t32 for 21-31 _1983 (6.30) 6.01, 5.77

rank 34 for 21-31 __ 1866 (6.03) in table

rank 38 for 21-31 __ 1859 (5.91) in table

rank not top 50 __ 1920 (5.53) in table

rank not top 50 __ 1875 (5.44) in table

2007 did not qualify for table at all, values were 5.92, 5.79, 4.55

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

^ Values for ranked 21st-31th Jan (above) not qualifying for top ten second half January:

Ranked _____ Average 16-31 ___ Ranked _____ Average 17-31

_03 21-31 ___ 2016 __ 5.69 ___ [][] _ 03 21-31 ___ 2016 __ 6.05 __

_12 21-31 ___ 1843 __ 5.92 ___ [][] _ 12 21-31 ___ 1843 __ 6.15 (in table) 

_19 21-31 ___ 1782 __ 4.26 ___ [][] _ 19 21-31 ___ 1782 __ 4.48 __

_20 21-31 ___ 1994 __ 5.69 ___ [][] _ 17 21-31 ___ 1994 __ 5.91 __

_21 21-31 ___ 1903 __ 4.84 ___ [][] _ 15 21-31 ___ 1903 __ 5.27 __

_23 21-31 ___ 2018 __ 5.76 ___ [][] _ 20 21-31 ___ 2018 __ 5.85 __

 

_30 21-31 ___ 1923 __ ..

_.03 __ [][] _ 30 21-31 ___ 1923 __ 6.01 

_30 21-31 ___ 1975 __ 5.71 __ [][] _ 30 21-31 ___ 1975 __ 5.77

 

2003 values 6.02 5.97 5.86

 

 

Thanks RS...

 Lots of interest in there..

Including how mild second half of January's have always been a regular event, and in many cases they were 'warmer' than current.

To me of the most interest is  that the years 1967,68,69 were 13th, 13th,  and 16th highest.

Most people think that period was cold, but in reality it was very changeable.,.

I haven't checked back to see what followed in February!!!!!

MIA

Edited January 19 by Midlands Ice Age

[Roger J Smith]

Feb 69 was quite cold (CET around 1 C) and had a strong northerly around 7th that set some records for wind speeds in Scotland. 

 

 

[Methuselah]

30 minutes ago, Roger J Smith said:

Feb 69 was quite cold (CET around 1 C) and had a strong northerly around 7th that set some records for wind speeds in Scotland. 

 

 

And we had at least two good dumpings in February 1969; one from a polar low running down the East Coast and another from an easterly blizzard caused by a depression that came up from France, 

PS: We also had a snowstorm in January 1968, along with minima below 14F lasting for five days; something we hardly ever see these days. 

Edited January 19 by Methuselah