Annual CET

[SqueakheartLW]

2014's record of 10.95C is still looking very much under threat as we stand based on the CET data up to 13th September

Averages so far this year:-

Average CET to August: 11.36

Normal CET to August: 9.78

Anomaly to August: 1.58

Provisional CET anomaly (up to 13th September): 1.53

Comparison with Extreme Annual CETs:-

The highest annual mean CET ever recorded was 10.95, which is 1.44 higher than normal. To beat this record the
anomaly must be higher than 1.22 for the remainder of this year

The lowest annual mean CET ever recorded was 6.86, which is -2.65 lower than normal. To beat this record the
anomaly must be lower than -12.51 for the remainder of this year

Using the provisional CET anomaly so far this year it stands at 1.53C which is still 0.09C above 2014's overall anomaly which if maintained at this level to the end of the year would give us our first 11C CET at 11.04C. This anomaly doesn't include the recent hot spell of 14th September and today and this number is very likely to creep up a little bit once these two days are included in the data.

We'd have to go some if we could somehow end up beating the lowest CET on record. Probably impossible now to get an anomaly of -12.51 for the rest of the year

[summer blizzard]

Assuming a final CET around 15C we should take 1st for Jan-Sep as 2011 and 2014 don't really gain on us given the similar CET. 2006 is still about 4C behind even with the September gain.

[Don]

On 15/09/2020 at 13:42, summer blizzard said:

Assuming a final CET around 15C we should take 1st for Jan-Sep as 2011 and 2014 don't really gain on us given the similar CET. 2006 is still about 4C behind even with the September gain.

If we get a CET of around 15C for September, that would mean June, July, August and September would all be very close compared to the same period in 2004!

[summer blizzard]

40 minutes ago, Don said:

If we get a CET of around 15C for September, that would mean June, July, August and September would all be very close compared to the same period in 2004!

Even May was ~0.5C out so yes, very quirky. 

[summer blizzard]

On 01/09/2020 at 14:27, summer blizzard said:

Rolling CET rose to 10.60.

As alluded to we did drop 2007 and 2017 in August and overtook 2014 however it turns out that 1990 is cumulatively the hottest year from Jan-August, we now rank second.

90.9 2020

87.9 2018

89.3 2017

89.6 2014

85.2 2011

88.8 2007

85.5 2006

88.6 2002

88.2 1999

91.2 1990

87.0 1949

In terms of September we can expect 2018, 2017, 2007 and 1990 to drop away as they were all relatively cool. Without a 15C September we can expect 2014, 2011, 2006, 1999 and 1949 to be arguing for the lead to end September.

Rolling CET actually fell thanks to the final third to 10.57C.

Adjusting my base list for comparison from Jan-Sep we see that we now have the hottest year to date CET on record albeit 2014 just missed out.

104.8 2020

101.6 2018

102.8 2017

104.7 2014

100.3 2011

102.6 2007

102.3 2006

103.0 2002

103.8 1999

104.4 1990

103.3 1949

In terms of October 1990 and 2014 both followed with warm October's (we would need to be 11.6C and 12.4C not to lose position respectively).

[SqueakheartLW]

Starting to see how the new 30 year average is shaping up compared to the last one

So far we have got 1991-2020 CET averages from January through to September

             Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct    Nov    Dec    Annual
91-20    4.7     4.9     6.7     8.9    11.9    14.7   16.8 16.5    14.2
             Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct    Nov    Dec    Annual
81-10    4.4     4.4     6.6     8.5    11.7    14.5   16.7 16.4    14.0   10.7    7.1     4.6      9.97

So far it looks like our means for each month have gone up yet again which continues to show the underlying warming trend of the last few decades. I imagine October to December will end up coming out higher too and the annual figures will almost certainly exceed 10C now as it was only 0.03 off with the 1981-2010 average.

[summer blizzard]

Rolling CET increased to 10.60C.

Adjusting my base list for comparison from Jan-Oct we see that we dropped from 1st in September to joint third.

115.3 2020

112.2 2018

115.2 2017

117.2 2014

112.9 2011

113.5 2007

115.3 2006

113.1 2002

114.5 1999

116.3 1990

115.0 1949

In terms of November we are likely to see the rolling CET rise based on current output. In terms of our ranking 2006 and 2014 were both 8C+ so we may stay around third.

[SqueakheartLW]

Mean Central England Temperature, 2020

Month          CET          Anomaly

January        6.4           +2.6

February     6.3           +2.5

March          6.7           +1.0

April             10.4         +2.5

May              12.5         +1.3

June              15.3         +1.2

July                15.7         -0.3

August          17.6         +1.8

September   13.9         +0.3

October        10.5          -0.1

November    8.5            +2.0

December    4.7             -0.5     (provisional, to the 1st)

Averages so far this year:-

Average CET to November: 11.27

Normal CET to November: 9.91

Anomaly to November: 1.35

Provisional CET anomaly (up to 1st December): 1.34

Comparison with Extreme Annual CETs:-

The highest annual mean CET ever recorded was 10.95, which is 1.44 higher than normal. To beat this record the
anomaly must be higher than 2.59 for the remainder of this year

What are the chances of us getting a +2.59 anomaly for December 2020, knowing our warming climate it is probably quite likely but with a -0.5C anomaly to start December then at present 2014's record of 10.95C is looking quite safe but if we head into a December 2015 type spell then we will smash 2014 quite easily and would very likely get an 11C year for the first time on record

The lowest annual mean CET ever recorded was 6.86, which is -2.65 lower than normal. To beat this record the
anomaly must be lower than -47.31 for the remainder of this year

Just imagine if we could achieve an anomaly of -47.31C for December 2020. It's probably never happened in the history of this planet in the UK. We would need a CET mean of -42.61C which I expect was never even achieved in any of the ice ages

[Don]

5 hours ago, SqueakheartLW said:

Just imagine if we could achieve an anomaly of -47.31C for December 2020. It's probably never happened in the history of this planet in the UK. We would need a CET mean of -42.61C which I expect was never even achieved in any of the ice ages

I think achieving an anomaly of -47.31C in December 2020 would almost make COVID-19 seem trivial!

[summer blizzard]

Rolling CET increased to 10.80C.

We rose back to second position in November however as we end the year it looks likely that we will probably finish a little below last year as things stand in terms of December so probably in third position for the year behind 2014 and 2006.

123.8 2020

120.5 2018

122.0 2017

125.8 2014

122.5 2011

120.8 2007

123.4 2006

121.6 2002

122.4 1999

123.2 1990

121.6 1949

[summer blizzard]

Annual CET came in at 10.76C, third warmest on record. 

[summer blizzard]

Rolling CET fell to 10.45C.

[Midlands Ice Age]

22 hours ago, summer blizzard said:

Rolling CET fell to 10.45C.

SB  - Is that up to Feb 1st or up to today?

 MIA 

Edited February 12, 2021 by Midlands Ice Age

[summer blizzard]

3 minutes ago, Midlands Ice Age said:

SB  - Is that up to Feb 1st or up to today?

 MIA 

Feb-January. Monthly.

[Midlands Ice Age]

29 minutes ago, summer blizzard said:

Feb-January. Monthly.

If we have a cold Feb (less likely but not impossible now), then how low does it have to go to be below 10.0 as last february was quite warm, if my memory is correct?. It seems strange that it can vary so much in such a short time period.

(ie above 11.0 to below 10.0), 

MIA

Edited February 12, 2021 by Midlands Ice Age

[Timmytour]

Will we ever get an annual CET below 9C again?   It might be argued that climate change will have put paid to it, but I'm not so sure.  Such years seem to come in clusters.  Mot recently we've had 1979 / 1985 / 1986  and before that 1956 / 1962 / 1963   .... a remarkably similar sequence of successive years following a six year wait!   The latter cluster was more impressive with another such year registering just two years later in 1965

While 2010 was the last time we had such a year, which ended a run of 23 years and we are now currently on a run of 10 years.  But 1956 marked the end of a 33 year run while 1979 marked the end of an 13 year run so perhaps the run we are on isn't completely out of the "new" normal.  But prior to 1956 the longest ever such wait had been 14 years, culminating in the winters of 1740 and 1879.

In earlier years there is undoubtedly a greater frequency of them, not just I suspect the respect of the cooler climate that existed back then, but also down to things like volcanic actions.  While there were a couple of VEI 5 volcanic eruptions around 1955 to 1957 I can't pinpoint a similar reasons for the cluster that began in 1979.  Maybe the eruptions of the Icelandic volcano in late March and early April 2010 had an impact on that  particular year, but it had already started on a pretty cold note.

I think we will see one in the none too distant future....and perhaps a small cluster of them.  The combined CET for Jan and Feb looks like it might end up  cooler than  it was in 1962 despite the milder end to February currently showing  on the models, so it's possible that this could be the year! 

 

 

 

[virtualsphere]

1 hour ago, Timmytour said:

Will we ever get an annual CET below 9C again?   It might be argued that climate change will have put paid to it, but I'm not so sure.   

I'm sure we will but as in 2010 I suspect it would be driven by larger negative winter anomalies, as it seems much rarer to see significantly colder months from April to October - probably because our colder summer months are caused by a northerly influence which naturally has a longer sea track over warming waters.  In winter, easterlies can still deliver continental cold, but as the continent warms in summer the same synoptics would likely be warm.  It would be interesting to see what would happen if we ever had a significant cold SST anomaly to the north of the UK in the summer though.

Best chance would probably be a sub 2C Jan / Feb and or Dec, colder March / Nov and then something cyclonic, wet and dull in the summer like July 2007 or June 2012. If we can go subzero for a month and / or get all three winter months under 3C like 2010 then we could still return some milder months during the rest of the year and end up below 9C.

[summer blizzard]

The main thing you need for a cold year is simply to avoid the mild spring/warm Autumn that we tend to get.

Jan 21

Feb 18

March 18

April 16

May 15

June 13

July 20

Aug 17

Sep 15

Oct 12

Nov 16

Dec 10

 

[virtualsphere]

On 16/02/2021 at 21:58, summer blizzard said:

The main thing you need for a cold year is simply to avoid the mild spring/warm Autumn that we tend to get...

 

It looks like the last time the annual CET fell below 9C without any winter month being below 2C (or indeed 3C) was in 1922.  I was wondering if it could be done using 21st century months but without any of the extremes in the winter.  I'm not quite sure how it's calculated but on the basis of purely averaging the months this should do it without any one month below 3C:  

Jan 21 (3.1),  Feb 09 (4.1), Mar 06 (4.9), Apr 12 (7.2), May 13 (10.4), Jun 12 (13.5), Jul 11 (15.2), Aug 14 (14.9), Sep 15 (12.6), Oct 12 (9.7), Nov 16 (5.6), Dec 17 (4.8)

That would be an atrocious summer though!

[BornFromTheVoid]

I thought some might find this interesting.
It's a comparison of the daily mean cold and warm records over time. A clear switch from record cold dominant to record warm dominant during the early 1900s, with the difference between the two accelerating from 1988 and continuing to do so.
Over the last 30 years (1991-2020) there's been 10 warm records for every 1 cold record. The previous 30 years (1961-1990) there was 2 warm for every 1 cold record.

[Timmytour]

There was an upward movement in annual CETs in the 20th century compared to the 19th century, but the extent of the shift upwards from the early 1990s has been remarkable!  

 

[summer blizzard]

Rolling CET for March-Feb fell to 10.35C, i believe that is the coolest value since Dec 19.

[Timmytour]

Ok........at present my curiosity regarding the possibility that this year will provide us with the next sub 9C Annual mean CET  - and the first since 2010 - has got me looking currently at the year of 1713.
For the comparison figures to date I am only basing March on the first 9 days of 2021, but some model runs currently suggest that it might not rise substantially from its present value....

 

 

If 2021 was going to follow 1713 it would put most months in the 30th percentile of  their mean CETs, with April, July and November particularly cold relative to their norms. That said, September in 1713 was relatively warm  even by today's standards and October and December were not far off the long term average.

[Relativistic]

It almost certainly won't be as cool as April or July 1713 this year. The last time the respective months were as cold were in 1922 and 1965. The other months are doable but it's hard to sustain prolonged below-average periods these days (the last time we did have such a period was precisely three centuries after 1713).

Our best bet would be cool to average until November, when we can start to see large negative anomalies even in the mod_ern era. A cold November followed by a very-cold December would do the trick if we were to be close to the 1961-90 average by the end of October.

Edit: Why is "mod_ern era" (minus the underscore) censored?

Edited March 11, 2021 by Relativistic

[summer blizzard]

Rolling CET for March-Feb fell to 10.40C due to the late warmth.

Without a repeat however its likely we lose some value during April however.