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

[Summer Sun]

0.4c to the 17th

4.1c below the 61 to 90 average
4.4c below the 81 to 10 average

[feb1991blizzard]

still confident my 3.4 wont be far away - maybe 0.5 or 0.7c too high but not out the question of being bang on - my 80 odd mm wont be far off although have a feeling i might be a little to low - maybe around 100mm.

[ItNeverSnowsInWindsor]

5 minutes ago, feb1991blizzard said:

still confident my 3.4 wont be far away - maybe 0.5 or 0.7c too high but not out the question of being bang on - my 80 odd mm wont be far off although have a feeling i might be a little to low - maybe around 100mm.

With all this mild weather it’s bound to get close to the 3s.

[feb1991blizzard]

Just now, prolongedSnowLover said:

With all this mild weather it’s bound to get close to the 3s.

i think there will be another dip just after xmas - by that stage that run of 10 max's will have it well over 2, its just then whether the cold will be colder than the running CET or just above and how long it lasts and what follows.

[Midlands Ice Age]

On 16/12/2022 at 16:36, Midlands Ice Age said:

According to the other thread (HIstory of 5 or more ice days),    2013 finished with 8 days.    We should get a 9th tomorrow (for today), but not certain about a 10th as milder air is seeping in on Saturday.

So yes it now goes back to Dec 10.

MIA

Well we actually managed another sub zero mean day yesterday (-1.3C).

That makes it then 10th on the trot now for this spell.

-1.1C, -0.8C, -0.5C,  -1.4C, -1.9C, -2.3C, -2.5C, -4.4C, -2.6C and today -1.3C.              10 days average is -1.88C.

 This makes it one of the most impressively cold spells for the length of cold achieved, in the last 150 years. (More details to follow) 

The mean value recorded today (-1.3C)  comprised of a minimum of -6.6C and a maximum for yesterday of +4.0C. 

This low of -6.6C is equal second lowest for the date 17th,  (ties with 1878), behind the -7.5C of 1859.

MIA 

LInk to my post in 5 Day  History thread for more details as to length and severity of the cold.

 

 

Edited December 18, 2022 by Midlands Ice Age

[Frigid]

Is there still a chance of this month having a colder anomaly than April 2021?

Edited December 18, 2022 by Frigid

[Relativistic]

9 minutes ago, Midlands Ice Age said:

Well we actually managed another sub zero mean day yesterday (-1.3C).

That makes it then 10th on the trot now for this spell.

-1.1C, -0.8C, -0.5C,  -1.4C, -1.9C, -2.3C, -2.5C, -4.4C, -2.6C and today -1.3C.              10 days average is -2.08C.

 This makes it one of the most impressively cold spells for the length of cold achieved, in the last 150 years. (More details to follow) 

The mean value recorded today (-1.3C)  comprised of a minimum of -6.6C and a maximum for yesterday of +4.0C. 

MIA 

 

 

Agree, some are really underselling this cold spell. I love snow but as long as it feels and looks Arctic outside I'm happy. I've seen some of the thickest frosts of my life during this spell; it's been nothing but beautiful.

Ten consecutive subzero means is somewhat rare, especially this early in the season.

[Optimus Prime]

A very cold spell of weather. How the ten day average of -2.1 C compares;

2010 managed a run of 11 consecutive days beneath freezing; averaging -4.2 C

Other than that year, you have to go back to 1981; -1.7 C

1962 9 days; -2.7 C

1890; a whopping 18 days below freezing averaging  -2.1 C and a lowest 10 day average of -3.1 C

Clearly 2010 is remarkable for the intensity but 1890 had longevity. 

Whilst this year isn't unprecedented, it is historically significant. 

 

Edited December 18, 2022 by Optimus Prime

[Roger J Smith]

The -6.6 yesterday was a minimum while 1859 was before the era of max-min so we're comparing the minimum to a mean daily in 1859, the min then was likely closer to -10. 

I don't think this month will have as large a negative anomaly at end of play as Apr 2021 but it could be close. The current guidance is fairly mild and the mean will gradually return to around 3 C. 

[Roger J Smith]

These are the 15 largest running CET (v2.0) temperature increases from 17th to 31st ... if a higher value than end of month is reached that is shown in brackets (e.g. 1782 was 2.9 on 30th). As a rough guide, the larger increases were due to means for 18-31 in the 6-8 C range, the smaller ones 4-6 C. There has never been a colder than 3.0 at mid-month to average anything like record warmth 18-31, if that happened this year just as a hypothetical, an average of 10.0 for 18-31 would change our 0.4 to 4.7 so that would probably be the theoretical limit (and an increase of 4.3). A more realistic estimate is probably similar to 1882 so from the lower starting point an outcome around 3.0. To top this list 2022 needs to reach 3.2 C. (edit _ 2022 does top the list, with 3.4 the final value, a rise of 3.0).

Rank ____ YEAR ____ CET 17 ___ CET 25 ___ CET 31 ___ Incr 17-31

_ 01 _____ 1803 _____ 1.7 _______ 3.6 _______ 4.4 _______ +2.7

_ 02 _____ 1882 _____ 1.3 _______ 2.7 _______ 3.9 _______ +2.6

_t03 _____ 1837 _____ 2.9 _______ 4.6 _______ 5.3 _______ +2.4

_t03 _____ 1987 _____ 3.0 _______ 4.4 _______ 5.4 _______ +2.4

_t05 _____ 1875 _____ 2.0 _______ 3.6 _______ 4.2 _______ +2.2

_t05 _____ 1991 _____ 2.3 _______ 4.2 _______ 4.5 _______ +2.2

_t07 _____ 1920 _____ 2.3 _______ 3.0 _______ 4.2 _______ +1.9

_t07 _____ 2012 _____ 2.8 _______ 4.1 _______ 4.7 _______ +1.9

_ 09 _____ 1782 _____ 1.0 _______ 2.4 ___(2.9) 2.8 ______ +1.8 

_t10 _____ 1879 _____-1.0 _______-0.3 _______ 0.7 _______ +1.7

_t10 _____ 1983 _____ 3.7 _______ 4.9 _______ 5.4 _______ +1.7

_t12 _____ 1781 _____ 3.8 _______ 5.1 _______ 5.4 _______ +1.6

_t12 _____ 1871 _____ 2.0 _______ 3.2 _______ 3.6 _______ +1.6

_t14 _____ 1902 _____ 3.1 _______ 4.4 ___(4.8) 4.6 _______ +1.5

_t14 _____ 1958 _____ 3.2 _______ 4.1 _______ 4.7 _______ +1.5

Edited January 1, 2023 by Roger J Smith

[Midlands Ice Age]

2 hours ago, Roger J Smith said:

These are the 15 largest running CET (v2.0) temperature increases from 17th to 31st ... if a higher value than end of month is reached that is shown in brackets (e.g. 1782 was 2.9 on 30th). As a rough guide, the larger increases were due to means for 18-31 in the 6-8 C range, the smaller ones 4-6 C. There has never been a colder than 3.0 at mid-month to average anything like record warmth 18-31, if that happened this year just as a hypothetical, an average of 10.0 for 18-31 would change our 0.4 to 4.7 so that would probably be the theoretical limit (and an increase of 4.3). A more realistic estimate is probably similar to 1882 so from the lower starting point an outcome around 3.0. To top this list 2022 needs to reach 3.2 C. 

Rank ____ YEAR ____ CET 17 ___ CET 25 ___ CET 31 ___ Incr 17-31

_ 01 _____ 1803 _____ 1.7 _______ 3.6 _______ 4.4 _______ +2.7

_ 02 _____ 1882 _____ 1.3 _______ 2.7 _______ 3.9 _______ +2.6

_t03 _____ 1837 _____ 2.9 _______ 4.6 _______ 5.3 _______ +2.4

_t03 _____ 1987 _____ 3.0 _______ 4.4 _______ 5.4 _______ +2.4

_t05 _____ 1875 _____ 2.0 _______ 3.6 _______ 4.2 _______ +2.2

_t05 _____ 1991 _____ 2.3 _______ 4.2 _______ 4.5 _______ +2.2

_t07 _____ 1920 _____ 2.3 _______ 3.0 _______ 4.2 _______ +1.9

_t07 _____ 2012 _____ 2.8 _______ 4.1 _______ 4.7 _______ +1.9

_ 09 _____ 1782 _____ 1.0 _______ 2.4 ___(2.9) 2.8 ______ +1.8 

_t10 _____ 1879 _____-1.0 _______-0.3 _______ 0.7 _______ +1.7

_t10 _____ 1983 _____ 3.7 _______ 4.9 _______ 5.4 _______ +1.7

_t12 _____ 1781 _____ 3.8 _______ 5.1 _______ 5.4 _______ +1.6

_t12 _____ 1871 _____ 2.0 _______ 3.2 _______ 3.6 _______ +1.6

_t14 _____ 1902 _____ 3.1 _______ 4.4 ___(4.8) 4.6 _______ +1.5

_t14 _____ 1958 _____ 3.2 _______ 4.1 _______ 4.7 _______ +1.5

Thanks

That is really interesting.... With a very mild next 2 days expected it should be around 1.5 by then.... after that  ???? 

[Frigid]

Any guesses on where the CET will be if the GFS 6Z came to fruition? Pretty unlikely but it's one of the possibilities so shouldn't be discounted. Cold from Christmas day to months end.

[Cymro]

1 minute ago, Frigid said:

Any guesses on where the CET will be if the GFS 6Z came to fruition? Pretty unlikely but it's one of the possibilities so shouldn't be discounted. Cold from Christmas day to months end.

I’m still quietly optimistic that my guess of 1.4 will be pretty close to the mark

[Frigid]

23 minutes ago, Cymro said:

I’m still quietly optimistic that my guess of 1.4 will be pretty close to the mark

If we see cold similar to Dec 2020 then I'm certain we'll see the coldest month since March 2013.

[Summer Sun]

0.6c to the 18th

4.0c below the 61 to 90 average
4.2c below the 81 to 10 average

[SummerShower]

Could we have a record jump in day on day CET today? It will definitely be in double figures today given that at 9am it was 12C and will still be so at 9pm - the same as the rest of the cet zone pretty much

Never known such a big switch day on day in winter..

[Frigid]

7 minutes ago, SummerShower said:

Could we have a record jump in day on day CET today? It will definitely be in double figures today given that at 9am it was 12C and will still be so at 9pm - the same as the rest of the cet zone pretty much

Never known such a big switch day on day in winter..

Yes I can't remember anything like this happening before. 10 days of sub zero CET days and then a 10C one, on par with some of Dec 2015 days. will be interesting to see where the CET sits at in 10 days time.. my guess is around 2.5-3.5C

[Weather Enthusiast91]

December has broken the 2022 trend for above average CETs. 

[The PIT]

Sunny Sheffield back to 1.4C -4.2C below average. Rainfall up to 30.4mm 34.7% of the monthly average.

[damianslaw]

Could well be in the 1s tomorrow, given how exceptionally mild last 24 hrs have been, remainder of the week up to christmas mild in the CET zone, but not the same degree, could be in the 2s by Christmas Day, then uncertainty, the end of the month could go quite cold, or stay average or indeed mild, a finish in the 2s or 3s most likely. 2012 saw a similiar switch mid month, became very mild after a 2 week cold spell, the mild lasted to month's end, will this be another 2012, or possibly more akin to say 2017 or 2020 that saw colder conditions post christmas, 2017 briefly so, 2020 more notably so.. still a high chance of first below average CET month this year.

[Roger J Smith]

Long overdue EWP update ... was 12.6 mm after 17 days, likely close to 20 mm now. GFS 12-day estimate (grid average) 80 mm, it adds up to 100 mm which is above most forecasts.

[Don]

3 hours ago, damianslaw said:

Could well be in the 1s tomorrow, given how exceptionally mild last 24 hrs have been, remainder of the week up to christmas mild in the CET zone, but not the same degree, could be in the 2s by Christmas Day, then uncertainty, the end of the month could go quite cold, or stay average or indeed mild, a finish in the 2s or 3s most likely. 2012 saw a similiar switch mid month, became very mild after a 2 week cold spell, the mild lasted to month's end, will this be another 2012, or possibly more akin to say 2017 or 2020 that saw colder conditions post christmas, 2017 briefly so, 2020 more notably so.. still a high chance of first below average CET month this year.

I think December 2022 will be colder than 2012 overall.

[Summer Sun]

1.0c to the 19th

3.5c below the 61 to 90 average
3.8c below the 81 to 10 average

[Roger J Smith]

CET min for 19th appears to be way lower than any reading during the 24 hour calendar day so I assume they just have some quirky pre-actual-time reporting period? Nobody else does it this way, all other weather data that I review for contests in other countries are 24h calendar day. You would have to go way back into the early part of the 18th to get a minimum of 0.5 as they report for the 19th. Their maxima seem okay. But the meteociel archived minima for 19th are considerably higher than 0.5. 

[Midlands Ice Age]

17 minutes ago, Roger J Smith said:

CET min for 19th appears to be way lower than any reading during the 24 hour calendar day so I assume they just have some quirky pre-actual-time reporting period? Nobody else does it this way, all other weather data that I review for contests in other countries are 24h calendar day. You would have to go way back into the early part of the 18th to get a minimum of 0.5 as they report for the 19th. Their maxima seem okay. But the meteociel archived minima for 19th are considerably higher than 0.5. 

Yep the minima just looks plain wrong.

Even if it was on a strict day relationship, we were at 7C at midnight, here in the centre of the CET zone.

That is why I asked if they had changed their timings or their data collection methods, Doesn't look correct.