December 2022 C.E.T. and EWP contests _ start of a new contest year

[Summer Sun]

1.4c to the 13th

3.1c below the 61 to 90 average
3.6c below the 81 to 10 average

[Roger J Smith]

I have been updating that table of record values and I noticed they are tinkering from day to day, the values changed for several data  points that I had placed in the table. For instance, the mean daily for 12th has changed from -0.1 to +0.1. The 13th is now given as -2.3. Perhaps they have been doing this all along but I had been under the impression the first numbers entered were left unchanged in v2.0. Might be just that in their excitement they forgot the +0.2 heat island adjustment. 

[LetItSnow!]

Say we’re somewhere in the mid 0s by the Sunday - how mild are Monday and Tuesday looking in the C.E.T. range at this point? Probably a hefty boost…but thereafter it’s looking like colder conditions maybe coming back, though still a way to go yet. Honestly feel like this month could end up anywhere from the 0s to the 3s. Certainly the coldest December since 2010.
 

How mild would it have to be to creep up over 4C? Out of curiosity. 

[Optimus Prime]

Assuming the CET is 0.7 C by the 17th then the remainder of the month will need to average;

10.2 = 5.0

9.2 = 4.5

5.2 = 2.7 (colder than March 2013 and coldest month since Dec' 2010)

8.1 = 4.0

-0.6 = 0.1 (equalling 1981)

-2.4 = -0.7 (equalling 2010)

-2.6 = -0.8 (equalling 1890)

 

Edited December 14, 2022 by Optimus Prime

[Frigid]

A swing to cold in the models, GFS being the coldest of all. If it came to fruition, a 0-2C December could be possible.. Anything can happen but what I am confident in, is this will be the coldest December since 2010.

[Roger J Smith]

A cold finish would end two quests for 2022, it could miss being warmest year (or make it a very close finish), but more likely, it will remove that high rank of its coldest month that I mentioned in a previous thread. I think 4.3 was going to start the damage on that statistic and something like 2.5 would make the outcome rather ordinary and out of the top ten. Will hunt that down near the end of this month to see where things stand. 

This was the list, and I've added the values that would tie 2022 with its nearest rivals (61 ranks ahead on one-decimal data) ... the values are to be compared to the two previous columns, and the number tied would include 2022 so right now each of these outcomes has one fewer ties:

CET Cold Rank avoidance rankings

_________ warmest ________ coldest (relative to normal)

YEAR _____ "highest" rank _____ "lowest" rank __ (relative to coldest) __ 2022 to tie

2022 _________ 3 (AUG) __________ t103 (JUN) ___t253 (10 tied)

2017 _________ 3 (MAR) __________ t164 (AUG) __t188 (14 tied) ____ 4.4 (t161, t194, 11 tied)

2005 _________ 3 (OCT) __________ t171 (DEC) __ t189 ( 6 tied) ____ 4.3 (t171, t188, 7 tied)

2020 _________ t4 (APR) __________ t184 (JUL) ___ t167 (15 tied) ____ 4.1 (t184, t176, 6 tied)

2002 __________ 8 (FEB) __________ t184 (JUL) ___ t167 (15 tied) ____ 4.1 (t184, t176, 6 tied)

2019 _________ t9 (FEB) __________ t190 (JUN) __ t163 (13 tied) _____ 4.0 (t189, t166, 11 tied)

1949 ___________t3 (SEP) __________t193 (MAR) ___ t163 (10 tied) _ above entry or below

1834 ___________t4 (JAN) __________ t199 (APR) ___ t152 (15 tied) __ 3.9 (t199, t153, 14 tied)

2004 __________t15 (AUG) _________ t199 (JUL) ___ t161 (6 tied) ____ 3.9 (t199, t153, 14 tied)

2006 _________ 1 (JUL, SEP) ______ t203 (MAR)*__t139 (24 tied) ____ 3.8 (t212, t149, 5 tied)

1761 ___________t41 (APR) ___________t218 (OCT) ___ t135 (13 tied) _ 3.7 (t216, t143, 7 tied)

1828 ___________t7 (DEC) ____________t219 (AUG) ___ t134 (13 tied) _ 3.7 (t216, t143, 7 tied) 

1832 ___________t68 (JUN) ___________t231 (FEB) ___ t128 ( 7 tied) ___ 3.6 (t222, t129, 15 tied) 

1911 ___________ 8 (AUG) ___________ t231 (OCT) ___ t124 (11 tied) __ 3.6 (t222, t129, 15 tied)

1914 ___________t14 (FEB) __________ t232 (JUL) ____ t125 (9 tied) ____ 3.6 (t222, t129, 15 tied)

1934 ___________ 2 (DEC) ____________t237 (MAR) ___ t125 (5 tied) ___ 3.5 (t236, t118, 12 tied)

1998 ___________t4 (FEB) ____________ t237 (JUL) ____ t120 (9 tied) ___ 3.5 (t236, t118, 12 tied)

1943 ___________t4 (APR) ____________ t239 (JUN) ___ t112 (15 tied) __ 3.5 (t236, t118, 12 tied)

2008 ___________t9 (JAN) _____________t239 (JUN) ___ t112 (15 tied) __ 3.5 (t236, t118, 12 tied) 

1982 ___________t43 (NOV) __________t239 (JAN) ____t120 (7 tied) ____ 3.5 (t236, t118, 12 tied)

2016 _________ 5 (SEP) ______________ t242 (NOV) __ t110 (14 tied) ___ 3.4 (t247, t111, 8 tied)

1857 __________ t9 (DEC) ____________ t246 (JAN) ___ t115 ( 5 tied) ____ 3.4 (t247, t111, 8 tied)

2014 __________ t6 (APR) ____________ t246 (AUG) __ t110 (10 tied) ____ 3.4 (t247, t111, 8 tied)

__ (only recent years since 2000 listed after this) __ 

2007 _________ 2 (APR) ___________ t246 (JUL) ___ t100 (20 tied) ___ 3.4 to next entry

2000 _________t24 (MAR) _________ t246 (JUL) ___ t100 (20 tied)

2001 _________ 1 (OCT) ___________ t248 (DEC) ___ t111 (7 tied)

2018 _________ 3 (JUL) _____________t249 (FEB) ____t110 (7 tied)  

2003 _________ t6 (AUG) ___________t254 (OCT) __ t106 (6 tied) ___ 3.3 (t254, t105, 7 tied)

2011 _________ 1 (APR) ____________t264 (JUN) ____ t94 (8 tied) ___ 3.2 (t260, t100, 6 tied)

2015 _________ 1 (DEC) ____________t266 (SEP) ____ t89 (11 tied) __ 3.1 (t265, t95, 6 tied)

2009 _________t12 (NOV) _________ t271 (DEC) ____ t81 (14 tied) ___ 3.0 (t270, t81, 15 tied)

2012 _________ t4 (MAR) __________ t284 (JUN) ____ t68 (14 tied) ___ 2.9 (now only 1756, t284, t80)

--- any outcome 2.8 to 2.1 will fall in this range ---

2021 _________ t6 (SEP) ___________ t316 (APR) ____ t40 (10 tied) ___ 2.0 (t317, t44, 5 tied)

--- any outcome 1.9 to 0.8 will fall in this range ---

2013 _________ t8 (JUL) ____________t348 (MAR) ___ t14 (4 tied) _____ 0.7 (now only 1879, t348, t16)

2010 _________t58 (JUL) __________ 363 (DEC) _____ 2 (none tied) ___-0.7 (now only 2010)

 

Edited December 14, 2022 by Roger J Smith

[LetItSnow!]

12 minutes ago, Frigid said:

A swing to cold in the models, GFS being the coldest of all. If it came to fruition, a 0-2C December could be possible.. Anything can happen but what I am confident in, is this will be the coldest December since 2010.

Indeed… a little more confident of the 0-2 side of things now but a lot to be sorted still! I would love a sub 1C finish.

[damianslaw]

Fully expect to be in the 0s by Friday, the low point will come on Saturday, next week looking quite cold as well, not expecting a major rise in the CET, but hard to say where we will end up, possibly in the 2s, 3s at the most.

Edited December 14, 2022 by damianslaw

[damianslaw]

2 hours ago, Optimus Prime said:

Assuming the CET is 0.7 C by the 17th then the remainder of the month will need to average;

10.2 = 5.0

9.2 = 4.5

5.2 = 2.7 (colder than March 2013 and coldest month since Dec' 2010)

8.1 = 4.0

-0.6 = 0.1 (equalling 1981)

-2.4 = -0.7 (equalling 2010)

-2.6 = -0.8 (equalling 1890)

 

That would be an achievement to record the coldest month since Dec 10..

[North-Easterly Blast]

2 hours ago, Frigid said:

A swing to cold in the models, GFS being the coldest of all. If it came to fruition, a 0-2C December could be possible.. Anything can happen but what I am confident in, is this will be the coldest December since 2010.

Well to make this month the coldest since 2010 it would only need a CET of 4.7 or less.  That is almost a certainty now.

In order for 2022 to record the first ever 11*C+ calendar year the December CET needs to be 2.5 or more.

It looks set to turn much milder by the 18th / 19th of this month, but some models are suggesting that the cold could return after that, but to be fair, a mix of milder and colder outcomes are being shown as possibilities in the ensembles, over the Christmas period and beyond.  Although the first half of December will have been notably cold, with a significant cold spell in the second week to mid-month, it is still too early in my opinion to say where this month's final CET is likely to end up.

[Roger J Smith]

I think the suggestion was coldest month of any name since DEC 2010 and that would have to beat 2.8 in v2.0 for MAR 2013. The next closest was 3.1 in FEB 2018. 

The coldest since marks before DEC 2010 (unlikely to come into play here) would be -1.0 (FEB 1986), -2.1 (JAN 1963), which as coldest goes all the way back to JAN 1814 (-2.9). 

I think the interval from 18th to 31st will average about 5 and bring the month in somewhere around 2.5; it looks highly variable and a windstorm is a distinct possibility given that gradient. Energy peak around 22nd-23rd needs to be closely watched. I don't put more than medium confidence in any model output beyond around Monday and it could easily go to either a very mild pattern or return to blocking and cold, as well as what is now shown. 

[Roger J Smith]

Worth noting that we would have to wait until November 2055 to break the futility record for subzero CET outcomes, 44 years and 11 months, that is held by Feb 1895 to Jan 1940 (Feb 1929 managed 0.4, and there was a subzero non-calendar month hiding between Jan 13th and Feb 12th of 1917). The second longest such interval is 24 years 10 months (Feb 1986 to Dec 2010) with a marginal near-zero hidden month in 1991. Before 1895 the longest was 24 years (Jan 1716 to Jan 1740), then 22 years 11 months (Feb 1740 to Jan 1763), followed by 19 years 10 months (Feb 1855 to Dec 1874) with a very cold hidden "month" in Dec 1860-Jan 1861 (average about -1.6). Jan 1838 to Feb 1855 (17 years 1 month) got past some near misses in the 1840s. This was the same interval without a subzero month from Dec 1796 to Jan 1814 (17 years 1 month). Before 1716 the longest interval without a subzero CET month was 18+ years (the record began with 1659 and the first subzero month was Dec 1676, however in that interval Jan 1660 and 1667 both had an average of 0.0. No telling how far back from 1658 that gap might have extended, if we exclude the 0.0 months; it should be noted that all months in the Maunder minimum have provisional estimates to nearest 0.5 so chances are good that one of those 0.0 months was actually slightly lower. 

The shortest gap between subzero months excluding four cases of consecutive ones (Jan-Feb 1684 and 1740, Dec 1878-Jan 1879, and Jan-Feb 1963) would be the 23 months from Jan 1795 to Dec 1796 and close to that record, 24 months between Jan 1879 and Jan 1881. It was just one year between 0.0 Jan 1694 and -1.0 Jan 1695. 

 

[Weather-history]

Some remarkable CET daily mean differences from cold to mild over a short space of time during the winter season

Jan 1867

4th: -9.0

7th: 9.6

Dec 1874/ Jan 1875

31st: -5.1

2nd: 6.2

 

Dec 1878

25th: -6.3

2nd: 6.2

Dec 1908/Jan1909

30th: -2.9

2nd: 7.5

 

Dec 1916/Jan 1917

27th: -1.1

1st : 9.9

 

Jan/Feb 1945

26th: -7.5

1st: 7.1

 

Jan 1958

22nd: -2.8

28th: 9.3

1985

Nov/Dec

29th: -0.8

2nd: 12.0

[The PIT]

Sunny Sheffield down to 1.5C -4.4C below average. Rainfall unchanged.

[kold weather]

13 hours ago, North-Easterly Blast said:

Well to make this month the coldest since 2010 it would only need a CET of 4.7 or less.  That is almost a certainty now.

In order for 2022 to record the first ever 11*C+ calendar year the December CET needs to be 2.5 or more.

Just to quickly correct a few things, the coldest month since 2010 would be March at 2.8c. This is probably still quite likely unless one of the milder solutions pans out.

To avoid 11c we need December to be 1.8c or below. Certainly in the realms of whats possible providing what we get next week is nothing more than a milder blip and we revert to below average again sooner rather than later.

To avoid the warmest ever year we need 1.3c or lower. Given the cold ground should be fairly well embedded max temps may well be slightly lower than you'd expect once we lose any outright mild feed, so this is certainly possible as well.

Any really strong cold shot puts an ice month at least within the realms of possibility, though I suspect we will probably fall within the 1-2c range in the end.

[Midlands Ice Age]

A heads up...

Today is the day for a possible all time date record for the CET low max within the CET area.

Current CDET V2.0 value is +0,4C.

It is going very close with the bitterly cold night only slowly warming up.

I have maxed here at +0.5C (dropping already) in a suburban  area in the middle of the CET area.

Fingers crossed for the 3 sites!!!.

MIA

 

 

Edited December 15, 2022 by Midlands Ice Age

[Midlands Ice Age]

Also whilst scouting around the metoffice.gov website I found this for the recent 7 day period -

CET figures for 8th to 14th Dec...

-1,1,     -0.8,     -0.5,    -1.4,    -1.9,    -2.3,    -2.5C . (obviously unofficial,  as yet) 

Todays will also probably be mid -2.s (possibly lower).

Looks all set for a near record breaking December 10 day mean. (as previously discussed above).

MIA

[Frigid]

On 29/11/2022 at 04:15, Roger J Smith said:

That was the largest drop by 7.4 deg, in CET v2.0, from 7.5 to 0.1.

The second largest was 6.6 deg, a tie between 1817 (9.1 to 2.5) and 1822 (8.2 to 1.6), then 1890 fell 6.5 (5.7 to -0.8), 1846 dropped 6.4 (6.9 to 0.5), 1788 fell 6.3 (6.0 to -0.3) which was duplicated by 1899 (8.5 to 2.2), 1730 down 5.8 (from 9.2 to 3.4) which was matched by 1874 (5.6 to -0.2), and 2010 (5.1 to -0.7), all just ahead of 1818 at 5.7 (9.5 to 3.8) and 1732, 1963 and 2009 at 5.6 (7.2 to 1.6), (8.2 to 2.6) and (8.6 to 3.0).

1678, 1680, 1844, 1917 and 1939 had falls of 5.5 deg (6.0 to 0.5), (6.5 to 1.0), (5.9 to 0.4), (7.8 to 2.3) and (8.7 to 3.2).  1995 rounds out the top twenty at 5.4 (7.5 to 2.1). 

Although 1938 only fell by 5.0 (9.4 to 4.4) it's worth noting that by mid-month there was severe cold and snow for about a week, after a November with a very similar profile to this year. Also 1946 fell 5.0 from 8.1 to 3.1 C. 

It's interesting that these large falls in temperature at the start of winter appear to cluster, more than half of the years that are listed are in pairs either one or two years apart. This may speak more to the tendency of mild Novembers to follow soon after a previous example, since to get these large drops to December you generally need to start from a reasonably mild November.

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

will post a forecast on the 30th, current guidance has me thinking very cold CET but if that cold signal weakens we could easily end up in more average territory. 

Could we see another big drop from November to December?

To beat the largest Nov to Dec CET drop we need December to be at 1.6C or below.

Current CET is at 1.1C, expecting this to go down to mid to upper 0s by Saturday. From there it could go anywhere. Latest model runs are hinting at something colder at months end, but probably not as severe as this week.

 

A very coid first half to December, would be interesting to see where this stacks up with previous Decembers. 

Edited December 15, 2022 by Frigid

[Summer Sun]

1.1c to the 14th

3.4c below the 61 to 90 average
3.8c below the 81 to 10 average

[LetItSnow!]

After a plethora of different runs so far today, I still am no more confident whether we’ll end up in the 0s or 3s.  

[summer blizzard]

On 02/12/2022 at 22:26, Roger J Smith said:

The lowest values for 1981, 2010 and the rest of the years since 1940 in groups ... it hasn't been all that cold since 2010 or even 2012 so I listed the coldest values 2013-21 after 2012 took all three of the post-2010 honours.

 

LOWEST CET VALUES (1-10, 1-15, 1-20)

Dates ___ 1981 ___ 2010 _____ 1982-2009 ___ 1940-1980 ___ 2011-2021 ___ 2013-2021

1-10 _____ 2.8 _____ -1.3 _______ 2.1 (2008) ____ 1.3 (1952) ____ 2.9 (2012) ____ 3.7 (2020)

1-15 _____ 0.6 ______ 0.0 _______ 1.9 (1991) ____ 1.7 (1950,76) _ 2.3 (2012) ____ 3.6 (2017)

1-20 _____-0.3 ______-0.7 _______ 3.0 (1990) ____ 1.6 (1976) ____ 3.2 (2012) ____ 3.6 (2017)

_________________

1981 reached its lowest value on 26th at -0.5, 2010 on 8th (-2.2) and later 27th (-1.45). 

2012 was lowest at 1.9 for 1-13 Dec. 

1962 was at -0.3 for 1-5, warmed to 3.7 by 21st then fell to 1.8 at end of month.

Another cold start was 1987 with 2.1 for 1-14. 

 

2 hours ago, Frigid said:

Could we see another big drop from November to December?

To beat the largest Nov to Dec CET drop we need December to be at 1.6C or below.

Current CET is at 1.1C, expecting this to go down to mid to upper 0s by Saturday. From there it could go anywhere. Latest model runs are hinting at something colder at months end, but probably not as severe as this week.

 

A very coid first half to December, would be interesting to see where this stacks up with previous Decembers. 

I copied Roger’s post above to answer this. The first half and two thirds is not quite on par with the best but likely in a podium position since 1940.

[damianslaw]

5 hours ago, Midlands Ice Age said:

Also whilst scouting around the metoffice.gov website I found this for the recent 7 day period -

CET figures for 8th to 14th Dec...

-1,1,     -0.8,     -0.5,    -1.4,    -1.9,    -2.3,    -2.5C . (obviously unofficial,  as yet) 

Todays will also probably be mid -2.s (possibly lower).

Looks all set for a near record breaking December 10 day mean. (as previously discussed above).

MIA

A notably cold 7 day mean. Emphasises how I thought the peak of the cold is occuring today and yesterday. Rivalling some of the running means for December 2010, but the cold period will be shorter lived without the depth of cold that month.

[damianslaw]

5 hours ago, Summer Sun said:

1.1c to the 14th

3.4c below the 61 to 90 average
3.8c below the 81 to 10 average

Expect we will bottom out on 0.5 degrees by Saturday, not quite into negative territory, the opening days of the month were close to average. At the mid month stage and none the wiser where we will finish, looking very topsy turvy, mild probably be cancelled out by cold, probably a nearer average second half, erring on slightly below, a finish in the 2s somewhere could be a good bet.

[ItNeverSnowsInWindsor]

With a lot of mild weather forecast the CET looks to head towards 3c and maybe higher if it continues milder after Xmas!

[kold weather]

Hard to say where we are going beyond Wednesday, especially since the difference between the cold air and the very mild air zones is probably only a few hundred miles which at that sort of range is still uncertain.

I think one thing we can say is Monday and possibly Tuesday will be very mild indeed and will see the CET absolutely race up on those days.

I think odds are we WILL have the warmest year ever now, even if the mildest solutions don't happen.