Annual CET

[Lettucing Gutted]

Assuming August is 17C and we then equal all of the warmest months on record from 2006 (16.8C), 2001 (13.3C), 1994 (10.1) and 1974 (8.1C) respectively then the final Annual CET will be 10.38C at its possible warmest.  However if again August is 17C but we then equal all of the coldest months on record from 1674 (10.5C), 1740 (5.3C), 1782 (2.3C) and 1890 (-0.8C) respectively then the final Annual CET will be 7.8C at its possible coldest.

Edited September 1, 2013 by Craig Evans

[SomeLikeItHot]

After a quick calculation, if August finishes at 17.0C (will likely finish lower than that), and all of the remaining months of 2013 finish bang on the 1961-90 averages, then we will end up at around 9.3C as an annual CET value.

The key thing will be what happens during November and even more so December, which have much larger variance than sep &october. An Autumn like last year would end the year at around 9.2. A cold december (eg CET < 2.5) with that would drive it to or below 9.

[Relativistic]

The key thing will be what happens during November and even more so December, which have much larger variance than sep &october. An Autumn like last year would end the year at around 9.2. A cold december (eg CET < 2.5) with that would drive it to or below 9.

That's weird, last year's December needed <2.5C to get sub 9C, and for a minute I thought that might happen! A truly severe November or December would be welcome for the cold factor but also the fact that it could drive the annual CET down to sub 9C. Edited September 2, 2013 by 22nov10blast

[summer blizzard]

Rolling CET to September 1st is 9.2.

[Weather-history]

I think we are a cert of a sub 10.0C CET now.

[stewfox]

I think we are a cert of a sub 10.0C CET now.

 

 Given it was 10.22 at the end of October , around 9.9 now subject to November rounding.

 

Of course if was rounded up 1.2c degrees we would hit around 10c !

 

http://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

 

4cCET for  Dec would give us around 9.4c for the year

Edited November 30, 2013 by stewfox

[summer blizzard]

What are we looking at now?

[BornFromTheVoid]

What are we looking at now?

 

6.1C to 7.2C for December will give an annual CET of 9.6. While 4.9 to 6.0C will give an annual CET of 9.5C.

[SomeLikeItHot]

6.1C to 7.2C for December will give an annual CET of 9.6. While 4.9 to 6.0C will give an annual CET of 9.5C.

After corrections its looking like it will be pretty close to that 9.5-9.6 boundary.

 

So slightly above 61-90 and below other recent 30 year averages for the year.

[BornFromTheVoid]

It looks like the 30 year mean annual CET will remain on 10.0C (joint highest on record) after this year (1984-2013). Barring an CET next year of below 8.3C or above 11.2C, it will remain on 10.0C for the 85-14 period also.

[stewfox]

• Anomaly to November: -0.06
• Provisional CET anomaly (up to 22nd December): 0.07

 

So 0.01 above the long term mean for the year. Yet September was the only month close to the mean.

 

Months of contrasts

 

http://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

[summer blizzard]

What did we end up with.

 

............

 

I suspect that next year will see a cooler and drier than average Q4 but its hard to see any indication for Q1, Q2 or Q3.

Edited January 10, 2014 by summer blizzard

[Robbie Garrett]

CET was 10.575 right for 2013?

[BornFromTheVoid]

CET was 10.575 right for 2013?

 

Around 9.6C I think.

 

The current 12 month average is 10.0C. If March reaches the 81-10 average of 6.6, the rolling 12 month CET will be at 10.3.

[Lettucing Gutted]

Another thing to consider is that since the 2nd July 2013 we haven't had a single CET day at least 1 standard deviation below average although we almost had one on the 17th September 2013 and 23rd November 2013.  This must a record for the longest period without a single day at least 1 standard deviation below average.

Edited March 2, 2014 by Craig Evans

[Interitus]

What are the odds of a record breaking CET this year? Any cooling later in FI doesn't look enough at this stage to prevent a milder than average March so that will be a quarter of the way there. The anomaly required for the rest of the year is currently 1.17°C above 1961-90 average, though the last 9 or 10 months of the year over the last decade have averaged around +0.6.

Although the chances are against it, +1.17 months have been achieved fairly frequently over this decade in some months, spring/autumn in particular -

March 4, April 4, May 1, June 2, July 2, August 1, September 4, October 4, November 3, December 3.

 

It would be quite special if the remainder of the year is like 2006.

To paraphrase Spinal Tap "it goes up to 11".

[Summer Sun]

The record high yearly CET is 10.82c to beat this at the moment we need the CET anomaly to be higher than 1.16c each month for the rest of this year

 

The average CET to February 28th is 5.94c

 

The normal CET to the end of February is 3.78c

[Interitus]

The record high yearly CET is 10.82c to beat this at the moment we need the CET anomaly to be higher than 1.16c each month for the rest of this year

 

The average CET to February 28th is 5.94c

 

The normal CET to the end of February is 3.78c

 

Interesting that the value of 10.82°C from 2006 which is one year that is particularly affected by the flaw in annual CET calculation - i.e that months all have equal influence - so the 28 days of February contribute proportionately as much as 31-day months.

If the CET is calculated from the average of daily values, 2006 actually comes out on top at 10.86°C.

 

A year made up of the lowest daily means would average a sub-Arctic 1.98°C - similar to perhaps some colder Icelandic locations, whilst the highest means give a sub-tropical 16.46°C shifting our climate a similar distance to the south, maybe central Portugal a touch cooler than Lisbon but warmer than Porto.

Anyway, out of the 242 years data from 1772-2013 (inclusive) it takes an average daily rank of 73rd or above each day to match 2006 - the top 30% of values.

An 11°C average only requires being in the top 69/242 values each day.

If we take the rank of 69th and above as the average trajectory for the year, the consistently warm 1990 gets the furthest, on target to achieve 11 degrees as late as September 6th.

1990 was in the top 5 all year from February 6th, at which time 2006 was 106th.

2006 was very different and as late as March 24th it was 157th, 3.58 degrees colder than 1990 in first.

Even after the hot summer it still wasn't one of the top 20 warmest years til September 17th, top 10 October 13th and finally reaching 1st place on December 6th.

 

Using the current estimated data, this year is averaging consistently quite highly, was in 10th a couple of days ago currently 11th but even so the average is some way below 1990 at this stage 0.88°C showing how warm that year was. However, we are ahead of the 11 degree trajectory by 0.12 degrees.

Edited March 17, 2014 by Interitus

[Interitus]

As temperatures should be slightly cooler over the next few days, a quick update where we stand now. Using the estimated daily values (up to 20th March) after 79 days the daily mean is 6.4°C which is 7th warmest of 243 years.

Continuing at the 1981-2010 average would see a final daily average of 10.34°C which equates to an annual CET of 10.31° from monthly values.

Following the 81-10 averages for a while would still have the daily mean on target to beat the 2006 record up to April 19th.

As of the latest value, the running mean has averaged in the top 27% of values (rank 64/242) at which rate the final daily mean would be around 11.17°C giving an annual CET approximately 11.15°C

Bearing in mind that a first half of year like 1990 followed by a second half like 2006 would see a CET up around 11.35+, an 11 degree CET is probably a matter of when, rather than if.

[Don]

Well, the first CET quarter of 2014 has come in at 6.5C and this compares to just 3.1C last year!  However, it's still a little way behind 2007 (6.7C) and some way behind 1990 which came in at 7.4C.  The other recent year that had a cold first quarter was 2010 which came in at 3.4C.

 

1961-90 Average - 4.4C

1971-00 Average - 4.9C

1981-10 Average - 5.2C

 

I wonder how the rest of the year will pan out?  7 out of the last 9 months have been above average.  Have we slipped back into our warm pre-2008 pattern?

Edited April 1, 2014 by Don

[North-Easterly Blast]

Well, the first CET quarter of 2014 has come in at 6.5C and this compares to just 3.1C last year!  However, it's still a little way behind 2007 (6.7C) and some way behind 1990 which came in at 7.4C.  The other recent year that had a cold first quarter was 2010 which came in at 3.4C.

 

1961-90 Average - 4.4C

1971-00 Average - 4.9C

1981-10 Average - 5.2C

 

I wonder how the rest of the year will pan out?  7 out of the last 9 months have been above average.  Have we slipped back into our warm pre-2008 pattern?

It has been the case in recent years that we have seen an extended run of warm conditions following a year of colder weather, such as in 2010 (a cold year), after becoming cold in Dec 2009, which lasted until Jan 2011 and then Feb 2011 to March 2012 generally brought above average conditions.  From April 2012 to June 2013 we generally saw cooler / colder weather, then from July 2013 it changed back to warm conditions which has generally persisted for the last nine months.  This year is actually looking similar to 2002 at this stage, and the last 8 / 9 months have been very similar to 2001 / 2002 in the same period though only with a December quite a bit milder than Dec 2001.  April at this stage looks to be setting up like 2002; this April probably won't be like 2007 / 2011, but an April like 2002 looks very likely for this year.

 

It was certainly the case that most years between 1988 and 2008 had very warm first quarters, and saw the most marked change of any period of the year in the 1988 to 2008 period, and since 2008 only 2010 and 2013 have seen a cold first quarter of the year.

 

The CET for the first quarter of the year has exceeded 6*C only 12 times since World War 2, and 9 of these have been since 1989.  I am not sure how many occasions the CET for the first quarter of the year has exceeded 6*C in the CET record, does anyone know?

Edited April 1, 2014 by North-Easterly Blast

[Don]

It has been the case in recent years that we have seen an extended run of warm conditions following a year of colder weather, such as in 2010 (a cold year), after becoming cold in Dec 2009, which lasted until Jan 2011 and then Feb 2011 to March 2012 generally brought above average conditions.  From April 2012 to June 2013 we generally saw cooler / colder weather, then from July 2013 it changed back to warm conditions which has generally persisted for the last nine months.  This year is actually looking similar to 2002 at this stage, and the last 8 / 9 months have been very similar to 2001 / 2002 in the same period though with a December quite a bit milder than Dec 2001.  April at this stage looks to be setting up like 2002; this April probably won't be like 2007 / 2011, but an April like 2002 looks very likely for this year.

 

Some good points raised about recent patterns.  It's easy to forget that after 2010 being our coldest year since 1986, 2011 went on to be the 2nd warmest on record!  What made this more surprising was the fact that Summer 2011 was cooler than average but was sandwiched between an exceptionally warm Spring and Autumn. However, this year there is the potential for strong el-nino conditions to develop.  It will be interesting to see how this pans out and what effects it will have on our weather during the next year or so.  Talking about comparing this year to 2002, I believe that year developed a weak el-nino?

Edited April 1, 2014 by Don

[Interitus]

Well the cooling at the end of March was slight, taking the running mean from 5th place on the 20th to 10th place between the 27th-31st.

Since then, the warmth has continued and since April 11th the estimated values give the running mean up into 3rd place, at first 0.31°C behind 1990 and by the 19th 0.25° behind new leader 2007.

Continuing at the same level as up to 17th April (averaging 63rd in daily ranking) would end up with an annual CET of around 11.18°C though this has just dropped back toward 11.15 in the last couple of days.

The 1981-2010 average would see the year end up around 10.42°C in about 17th place.

Last 10 year average would end up 10.53° in 8th place.

With the possibility of a 'super Nino' if the rest of the year is the same as 1997, the CET would be about 10.74°C in second place behind 2006.

[summer blizzard]

What are we looking at to the end of May?

[Interitus]

With data to May 26th we are still in 3rd place just 0.05°C behind 1990 and 0.27°C behind 2007.

The present anomaly would see a final annual value of about 11.11°C if it were to continue.

Continuing at the average of the last ten years would see this year move into 2nd place by June 8th and briefly into 1st place at the end of July before a final average of 10.60°C in 6th.

The 1981-2010 average would be 10.53°C in 8th.

This Spring is currently 5th 0.13°C behind 2011, then 2007, 1893 and 1945 and the last ten year average would see it sneak into third by month's end though perhaps unlikely now.

Overall, the current 12 rolling months is becoming quite significant in 10th and on target to be in 3rd by the middle of June above 10.9°C behind periods of 11.67°C in 2006-7 and 11.11°C in 1994-5.

 

Just to add, with El Nino in mind if this year were to continue exactly like 1997 then the final annual average would be a new record at 10.90°C

Edited May 28, 2014 by Interitus