January 2021 C.E.T. and EWP forecast contests

[Frigid]

Just now, damianslaw said:

Oh just scraped in then. Would be nice to see a sub 3 degree month this winter at least. Not had many such months in last 10 years, think only Feb 2013, Mar 2013 and Feb 2018, very poor showing!

how about a sub 2c month. 2010 had two sub 2c months and none after that. that would be great if it happened imo 

[damianslaw]

7 minutes ago, Don said:

Feb 13 had a CET of 3.2C, followed by a colder March with a CET of 2.7C.

Ok so only Feb 2018 - and only just, and March 2013 returned a mean below 3 degrees. Just two months in over 10 years (since Dec 2010).

[damianslaw]

8 minutes ago, Frigid said:

how about a sub 2c month. 2010 had two sub 2c months and none after that. that would be great if it happened imo 

A very tall order, these came in separate winters as well. We were not far off a double combo in Jan and Feb 2010. 

Had the cold arrived 2 weeks later in Dec 2009 then a very cold Jan and Feb 10 would have happened. It was a great winter for sustained cold. Also had the cold of Jan 13 arrived 2 weeks earlier then a possible sub 2 degree Jan and Feb would have happened. All ifs and buts.

Long way off but fair chance Jan 2021 could end up sub 3 degrees, but I wouldn't bet on it at such an early stage. 

[Don]

13 minutes ago, damianslaw said:

Ok so only Feb 2018 - and only just, and March 2013 returned a mean below 3 degrees. Just two months in over 10 years (since Dec 2010).

Poor but I don't think we had a sub 3C month between January 1997 and January 2010?

[Frigid]

I think the 2010s did quite good for cold months, much better than the 2000s. As for this month i feel like my prediction of 2.9 isn't too bad. We just need the effects of the SSW to arrive hopefully in the final week.

[Don]

5 minutes ago, Frigid said:

I think the 2010s did quite good for cold months, much better than the 2000s. As for this month i feel like my prediction of 2.9 isn't too bad. We just need the effects of the SSW to arrive hopefully in the final week.

Hopefully not too bad as I went for 2.9C, too!

[Summer Sun]

1.7c to the 7th

2.2c below the 61 to 90 average
2.6c below the 81 to 10 average

___________________________

Current high this month 1.7c on the 5th, 6th & 7th
Current low this month 0.5c on the 1st & 2nd

[Frigid]

12 minutes ago, Summer Sun said:

1.7c to the 7th

2.2c below the 61 to 90 average
2.6c below the 81 to 10 average

___________________________

Current high this month 1.7c on the 5th, 6th & 7th
Current low this month 0.5c on the 1st & 2nd

wow rly? Surely the CET went down after yesterday's ice day 

[feb1991blizzard]

8 minutes ago, Frigid said:

wow rly? Surely the CET went down after yesterday's ice day 

Its gone down today to 1.3c

[ItNeverSnowsInWindsor]

Should be another drop tomorrow with below freezing minimas widely.

[snowray]

2 hours ago, feb1991blizzard said:

Its gone down today to 1.3c

That’s what I calculated up to the 7th, exactly 1.3c.

[Frigid]

it should go down to 1c at least by day 10. perhaps lower 

[BornFromTheVoid]

Here's the latest forecast and probabilities

 

At the moment, we have 86% chance of finishing between 1.5C and 4.5C

The chances of finishing:
Close to average (3.9 to 4.9C) is 17.3% (3 days ago was 20.6%)
Above average (>4.9C) is 2.4% (3 days ago was 4.8%)
Below average (<3.9C) is 80.2% (3 days ago was 74.6%)

The above are all before corrections.

[The PIT]

Sunny Sheffield at 1.4C -3.1 degrees below normal. Rainfall 6.1mm 7.5% of the monthly average.

[damianslaw]

On 07/01/2021 at 21:45, Don said:

Poor but I don't think we had a sub 3C month between January 1997 and January 2010?

Not sure might have scraped one in Jan 2001, but think it returned 3.1 degrees. Dec 2009 and Jan 2009 must have come close. Dec 2001 not too far off. The 00's indeed was indeed a poor decade for cold months.

Mind the 90s were not much better, sub 3 degree months I think were Feb 91, Dec 95, Feb 96, Dec 96 and Jan 97.

[Optimus Prime]

Estimated CET tracker to the 15th

7th 1.3

8th 1.2

9th 1.1

10 1.2

11 1.5

12 1.8

13 1.9

14 2.2

15 2.4

Obviously doesn't compare too well to the top 8 coldest 1st - 15th January months since 1960;
 

1963 -1.6

2010 -0.9

1979 -0.4

1982 -0.4

1985 -0.3

1987 0.1

1997 1.0

2009 1.4

 

…2021 2.4 (estimate)

 

[Don]

1 hour ago, damianslaw said:

Not sure might have scraped one in Jan 2001, but think it returned 3.1 degrees. Dec 2009 and Jan 2009 must have come close. Dec 2001 not too far off. The 00's indeed was indeed a poor decade for cold months.

Mind the 90s were not much better, sub 3 degree months I think were Feb 91, Dec 95, Feb 96, Dec 96 and Jan 97.

January 2001 had a CET of 3.2C, December 2009 3.1C, January 2009 3.0C and December 2001 3.6C.  So, no sub 3C months during the noughties!  Very poor indeed and by comparison, the 90's were actually quite good, although poor in the grand scheme of things!  Meanwhile the 2010's also recorded recorded 5 sub 3C months, albeit the 90's did not experience an 'ice' month - January 2010 (1.4C), February 2010 (2.8C) , December 2010 (-0.7C), March 2013 (2.7C) and February 2018 (2.9C).  I wonder if January 2021 will be the first sub 3C month of the 2020's?!  Hope so as I went for a sub 3C CET!

Edited January 9, 2021 by Don

[Roger J Smith]

A longer historical perspective ...

 

LONGEST INTERVALS BETWEEN SUB 3.0 CET MONTHS 

Rank _ Interval ___________ Duration _______________ Coldest month in that interval

 1. Jan 1997 to Dec 2010 __ 13 years 11 months ____3.0 Jan 2009^

 2. Dec 1732 to Jan 1740 __ 7 years 1 month _______ 3.2 Feb 1736

 t3. Feb 1919 to Dec 1925 __6 years 10 months _____ 3.3 several

 t3. Feb 1970 to Dec 1976 __ 6 years 10 months ____ 3.7 Mar 1970 (3.9 Jan 1972)

 5. Feb 1909 to Nov 1915 __ 6 years 9 months ______3.5 Jan 1910

 6. Feb 1902 to Feb 1907 _ 5 years 0 months ______ 3.0 Dec 1906*

 7. Mar 2013 to Feb 2018 _ 4 years 11 months ____ 4.0 Feb 2015

 t8. Feb 1991 to Dec 1995 _ 4 years 10 months ____ 3.2 Feb 1994

 t8. Feb 1711 to Dec 1715 _ 4 years 10 months ____ 3.0 Jan 1712,1713

10. Feb 1936 to Jan 1940 __ 3 years 11 months ____ 3.0 Dec 1937

t11. Feb 1875 to Dec 1878 _ 3 years 10 months ____ 3.2 Jan 1876

t11. Feb 1947 to Dec 1950 _ 3 years 10 months ____ 3.6 Mar 1947 (4.2 Jan 1950)

(there were no other intervals longer than 3 years 3 months, in other words, this is the full list where three whole winters went without a sub-3.0 month). 

These twelve intervals add up to 72.6 years so there would be a 25% chance at random of being in any such interval at any point in 290 years (roughly 1730 to 2020) or a 20% chance in 363 years (the length of CET temps 1659 to 2021) ... the longest interval in the Maunder period was 3 yrs 1 mo (Jan 1685 to Feb 1688). We have been in a sub-3.0 "drought" of 3+ winters for 20 of the past 30 winters going back to 1991-92, and that would change to 23 if 2018-19 and 2019-20 are joined by this winter. By Dec 2021 this current "candidate" spell would join the tie for 11th place above. So we can avoid getting onto the list by hitting sub 3.0 this month or next, or March, and even November of this year would drop to 13th solo. 

______________________________________________________

^ If the metric was duration of no 3.0 or lower months, this spell would be 12 years 0 months and the coldest intervening month then becomes 3.2 Jan 2001. 

* If the metric was duration of no 3.0 or lower months, this spell would be 4 yrs 10 months and the coldest intervening month then becomes 3.1 in Feb 1906.

(note the durations are intervals between sub-3.0 months, the duration of the interval with no sub-3.0 month is two months shorter since it would not include the two end points).

 

Back in the day, sub-3.0 months were dime a dozen so to speak, there was at least one in every winter from 1806-07 to 1816-17, eleven winters, same interval as 2009-10 to 2019-20 when there were three winters with one. 

[The PIT]

Sunny Sheffield at 1.2C -3.3C below normal. Rainfall up to 7mm 8.6% of average.

[Summer Sun]

1.0c to the 8th

2.5c below the 61 to 90 average
3.3c below the 81 to 10 average

___________________________

Current high this month 1.7c on the 5th, 6th & 7th
Current low this month 0.5c on the 1st & 2nd

[damianslaw]

Quite a drop in the last couple of days, further drop likely in tomorrow's figure, then a rise, before a probable drop again in a week's time. Not seeing anything particularly mild in the coming days, means of about 4 degrees, but enough to pull values into the 2s by the mid month point. 

[Don]

6 minutes ago, damianslaw said:

Quite a drop in the last couple of days, further drop likely in tomorrow's figure, then a rise, before a probable drop again in a week's time. Not seeing anything particularly mild in the coming days, means of about 4 degrees, but enough to pull values into the 2s by the mid month point. 

As long as the CET is below 3C at the end of the month, I will be happy!

[NeilN]

If all this comes off with the models for a cold spell mid-month onwards, I can see a sub 2c month!! 

[Roger J Smith]

Assuming first ten days will be around 0.8 after corrections at end of month, I looked at my data to find all similar starts to January, a fairly broad selection chosen, 0.1 to 1.5 means through 10 days, but they are arranged in order of departure from 0.8 C. By the way, there were 31 cases in the daily data period (1772 to 2020) with lower means (0.0 to -3.5) by 10th. The warmest outcome for any of those was 3.9 from 0.0 in 1868.

Year ___ CET 1-10 ___ Outcome ______________ Year ___ CET 1-10 ___ Outcome 

1967 ____ 0.8 ________ 4.5 ___________________  1867 ___ 0.4 ________ 1.2

1773 ____ 0.7 ________ 4.0 ____________________ 1804 ___ 1.2 ________ 5.8

1908 ____ 0.7 ________ 2.5 ____________________ 1821 ___ 1.2 ________ 3.6

1929 ____ 0.7 ________ 1.3 ____________________ 1826 ___ 1.2 ________ 0.4

1835 ____ 0.7 ________ 2.9 ____________________ 1838 ___ 1.2 ________-1.5

1833 ____ 0.9 ________ 1.2 ____________________ 1889 ___ 1.2 ________ 3.4

1815 ____ 0.6 ________ 0.3 ____________________ 1778 ___ 0.3 ________ 1.9

1849 ____ 0.6 ________ 3.9 ____________________ 1854 ___ 0.3 ________ 3.6

1918 ____ 0.6 ________ 3.8 ____________________ 1871 ___ 0.3 ________ 0.5

1892 ____ 1.0 ________ 2.3 ____________________ 1931 ___ 0.3 ________ 3.2

1940 ____ 1.0 ________-1.4 ____________________ 1831 ___ 1.3 ________ 1.6

1830 ____ 1.1 ________-0.2 ____________________ 1970 ___ 0.2 ________ 3.7

_______________________________________________ 1786 ___ 0.1 ________ 2.7

_______________________________________________ 1985 ___ 0.1 ________ 0.8

_______________________________________________ 1779 ___ 1.5 ________ 2.9

_______________________________________________ 1901 ___ 1.5 ________ 3.5

_______________________________________________ 1957 ___ 1.5 ________ 3.3

____________________________________________________________________________________________

Of these 29 cases that are closest to 2021, only five saw a further drop in CET and four others stayed below 1.5 while increasing; the rest all got considerably milder and the average of all 29 at end of month is 2.3 C. 

 

 

[Don]

36 minutes ago, NeilN said:

If all this comes off with the models for a cold spell mid-month onwards, I can see a sub 2c month!! 

All the better!  I'm more than happy to be too high this month!