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

[Roger J Smith]

Posted this on the first, seems like 2021 could join this rather small group ... 

 

These Aprils were colder than or same CET,  as March preceding them ... full list in reverse chronological order. 

The more notable cases are in the first of two columns.

 

(0.5 or more colder) ____________________________________ (0.0 to 0.4 colder)

YEAR _______ MAR __ APR __________________ YEAR _______ MAR __ APR

 

2012 _______ 8.3 ____ 7.2 _ (-1.1) ____________ 1998 _______ 7.9 ___ 7.7 _ (-0.2)

1989 _______ 7.5 ____ 6.6 _ (-0.9) ____________ 1991 _______ 7.9 ___ 7.9 _ (-0.0)

1938 _______ 9.1 ____ 7.6 _ (-1.5) ____________ 1990 _______ 8.3 ___ 8.0 _ (-0.3)

1936 _______ 7.1 ____ 6.3 _ (-0.8) ____________ 1981 _______ 7.9 ___ 7.8 _ (-0.1)

1903 _______ 7.1 ____ 6.4 _ (-0.7) ____________ 1978 _______ 6.7 ___ 6.5 _ (-0.2)

1809 _______ 6.0 ____ 5.2 _ (-0.8) ____________ 1957 _______ 9.2 ___ 8.9 _ (-0.3)

1780 _______ 7.9 ____ 6.3 _ (-1.6) ____________ 1790 _______ 6.4 ___ 6.1 _ (-0.3)

1750 _______ 8.2 ____ 7.7 _ (-0.5) ____________ 1702 _______ 5.8 ___ 5.8 _ (-0.0)

__________________________________________________________

So only fourteen times out of 362 saw a decrease, two more stayed on the same value, and long intervals without any cases at all, such as 1810 to 1902, and all years before 1702. 

The phenomenon has become more common recently, and occurred three times in a row 1989 to 1991. Of the 16 cases, half were in the recent past (1957 to 2012). Two more were in the 1930s.

1743 only warmed by 0.1 (5.3 to 5.4) which is the coldest March to see that small an increase into April.

The two warmest Marches (1957, 1938) are in the list, along with other warm cases like 2012, 1990 and 1750.

 

[Roger J Smith]

In addition to the above, even small increases (0.1-0.5) from March to April are not that common, this is the full list of them. 

Incr 0.1 __ 1743 (5.3 to 5.4)

Incr 0.2 __ 2017 (8.7 to 8.9), 2000 (7.6 to 7.8), 1950 (7.4 to 7.6), 1859 (7.3 to 7.5)

Incr 0.3 __ 1977 (6.9 to 7.2), 1849 (6.1 to 6.4), 1841 (7.5 to 7.8)

Incr 0.4 __ 1994 (7.7 to 8.1), 1983 (6.4 to 6.8), 1777 (6.8 to 7.2)

Incr 0.5 __ 1905 (6.8 to 7.3), 1822 (7.8 to 8.3), 1710 (6.0 to 6.5) 1680 (6.0 to 6.5)1677 (7.0 to 7.5)

note: 1699 is the first year that has values not multiples of 0.5 .. 1707 to 1721 are also all multiples of 0.5.

therefore for most of the years 1659 to 1721, a year could only join this list at 0.5. (it would be in the previous list at 0.0).

_________________________________

Once again in this group of 16, five were recent (1977-2017) and with two hits before 1702, when generally speaking 0.5 or 1.0 would be the only choices for small increases, so looking for 1.0 in that era I found just 1659 (6.0 to 7.0) and 1713 (4.5 to 5.5).

[Roger J Smith]

In case you were wondering, Mays cooler than preceding Aprils are quite rare too. (seems we could rule that out for 2021) ... This is the entire list including cases to +0.5 ... the first was in 1755.

colder ___1987 (10.3 to 10.1), 1894 (9.7 to 9.2), 1869 (10.1 to 9.6), 1821 (9.5 to 9.4), 1814 (9.6 to 9.2), 1755 (10.0 to 9.4)

same ____ (no cases)

0.1 to 0.5 incr __ 2011 (11.8 to 12.2), 1955 (9.3 to 9.7), 1874 (9.8 to 10.0), 1796 (10.2 to 10.3), 1792 (10.0 to 10.2), 1783 (10.1 to 10.4)

So there were even fewer Mays that were cooler or marginally warmer, just six cooler and  six marginally warmer. 1996 was 0.6 warmer and 2007 was 0.7 warmer to fall just outside this group. 

Also, no May has ever been colder than its preceding March but in 1957 the difference was only 1.1, in 1938 it was 1.6. It would take a top ten March to stand any chance in this unequal contest. 

Edited April 25, 2021 by Roger J Smith

[LetItSnow!]

Even though some have found it rather miserable, I've thoroughly enjoyed what it feels like to go through such an remarkably cooler than average month (especially the minima). Especially since April has been a mild affair pretty much since 1992 bar the odd exception. I hope this is the sign of things like this being more common. This year has a different feel to it, & May is looking to start cool too...

[The PIT]

Sunny Sheffield up to 6.4C  -2.1C below average. Rainfall unchanged.

Looking like we end up around 6.4C to 6.7C here.

[mulzy]

7 hours ago, LetItSnow! said:

Even though some have found it rather miserable, I've thoroughly enjoyed what it feels like to go through such an remarkably cooler than average month (especially the minima). Especially since April has been a mild affair pretty much since 1992 bar the odd exception. I hope this is the sign of things like this being more common. This year has a different feel to it, & May is looking to start cool too...

Like a lot of people, I do like it cold in Winter especially as this increases snow chances.  But cool from May onwards is a no-no - most of us want a bit of warmth and the sun on our back - I think it's a natural human instinct and we all know the sun plays a huge role in our mood!

Edited April 26, 2021 by mulzy

[Earthshine]

2 hours ago, mulzy said:

Like a lot of people, I do like it cold in Winter especially as this increases snow chances.  But cool from May onwards is a no-no - most of us want a bit of warmth and the sun on our back - I think it's a natural human instinct and we all know the sun plays a huge role in our mood!

Yep cold belongs in winter.  Especially now with pubs and cafes openeing I think we all deserve some warmer weather after what has been an absolutely horrid winter.

[Timmytour]

1 hour ago, Earthshine said:

Yep cold belongs in winter.  Especially now with pubs and cafes openeing I think we all deserve some warmer weather after what has been an absolutely horrid winter.

You just know that after last year's perfect weather for sitting outside a pub when we weren't allow to go to the pub, it won't warm up until 17th May when, after five weeks of freezing our KPs outside the pub,  we are finally allowed to go inside it!

[Summer Sun]

6.8c to the 25th

0.9c below the 61 to 90 average
1.4c below the 81 to 10 average

___________________________

Current high this month 8.8c on the 1st
Current low this month 5.6c on the 12th, 13th, 15th & 16th

[BornFromTheVoid]

6.8C or 6.9C are likely to be the final values, then anything down to 6.3C after corrections seems possible.

[Relativistic]

On 16/04/2021 at 14:39, Relativistic said:

The mean minimum CET is worth keeping an eye on. To the 16th the provisional figure is 1.2C, which becomes 1.0C with our modest correction. If the remaining 14 days averaged a little over 3.0C we'd still end up fifth-coldest on record; 4.0C lands us at around 10th and 5.0C around 20th.  For context, the coldest is 1.4C from 1917.

Ten days later and the provisional figure is 1.6C, so a mean of 4.6C for the remaining four days would take us to 2.0C. Current forecasts suggest that this is unlikely to happen now, and that April 2021 could join one of only four other Aprils to record a sub-2C minimum CET -- the first to do so in 99 years.

Precisely where we end up in the rankings will depend on the magnitude of the end-of-month correction.

Edited April 26, 2021 by Relativistic

[Frigid]

34 minutes ago, Relativistic said:

Ten days later and the provisional figure is 1.6C, so a mean of 4.6C for the remaining four days would take us to 2.0C. Current forecasts suggest that this is unlikely to happen now, and that April 2021 could join one of only four other Aprils to record a sub-2C minimum CET -- the first to do so in 99 years.

Precisely where we end up in the rankings will depend on the magnitude of the end-of-month correction.

That would make it lower than the December and February min CET we just had. Crazy to think about as its mid Spring. 

[Weather-history]

On 22/04/2021 at 05:18, Weather-history said:

Coldest, driest April is 1855, I think with a CET: 7.1C and 19.9mm

Top 30 driest Aprils on record with their CETs

1938: 7.6

1817: 7.6

1912: 8.8

1957: 8.9

1893: 10.3

1785: 8.4

2011: 11.8

1854: 9.2

1842: 7.8

1974: 8.2

1783: 10.1

1954: 7.6

1844: 9.8

1980: 8.8

1976: 8.1

1855: 7.1

2017: 8.9

1852: 8.2

1870: 9.2

1801: 8.3

1776: 9.4

1807: 7.7

1778: 8.2

1873: 7.7

1997: 9.0

1840: 9.7

1982: 8.6

1806: 6.8 (26.8mm)

 

 

[mushymanrob]

50 minutes ago, Weather-history said:

Top 30 driest Aprils on record with their CETs

1938: 7.6

1817: 7.6

1912: 8.8

1957: 8.9

1893: 10.3

1785: 8.4

2011: 11.8

1854: 9.2

1842: 7.8

1974: 8.2

1783: 10.1

1954: 7.6

1844: 9.8

1980: 8.8

1976: 8.1

1855: 7.1

2017: 8.9

1852: 8.2

1870: 9.2

1801: 8.3

1776: 9.4

1807: 7.7

1778: 8.2

1873: 7.7

1997: 9.0

1840: 9.7

1982: 8.6

1806: 6.8 (26.8mm)

 

 

So we are likely to be colder and drier than all of those years except for 1806.... crikey...

[The PIT]

Sunny Sheffield up to 6.5C -2.0C below normal. Rainfall unchanged.

Using local forecast and adjusting the forecast highs as they tend to be 2 degrees two low gives sunny Sheffield a value of 6.5C to finish the month. Coldest since 1989.

[Summer Sun]

6.8c to the 26th

0.9c below the 61 to 90 average
1.5c below the 81 to 10 average

___________________________

Current high this month 8.8c on the 1st
Current low this month 5.6c on the 12th, 13th, 15th & 16th

[Timmytour]

When was the last time the Sheffield figures finished above the UK mean CET?  Not far off this month!

[Weather-history]

Top 30 driest Aprils on record with their CETs

1938: 7.6  (7.1mm)

1817: 7.6  (7.9mm)

1912: 8.8 (9.0mm)

1957: 8.9  (9.7mm)

1893: 10.3 (9.9mm)

1785: 8.4  (10.1mm)

2007: 11.2 (10.4mm)

1984: 8.1 (10.8mm)

2011: 11.8 (11.6mm)

1854: 9.2  (14.1mm)

1842: 7.8 (14.3mm)

1974: 8.2 (14.3mm)

1783: 10.1 (15.2mm)

1954: 7.6  (16.1mm)

1844: 9.8  (16.6mm)

1980: 8.8  (17.5mm)

1976: 8.1  (19.0mm)

1855: 7.1  (19.9mm)

2017: 8.9  (19.9mm)

1852: 8.2  (20.1mm)

1870: 9.2  (21.5mm)

1801: 8.3  (21.6mm)

1776: 9.4  (22.4mm)

1807: 7.7  (22.9mm)

1778: 8.2  (23.0mm)

1873: 7.7  (23.1mm)

1997: 9.0  (23.7mm)

1840: 9.7  (24.2mm)

1982: 8.6 (25.4mm)

1806: 6.8 (26.8mm)

[cheeky_monkey]

cloudy Edmonton is at 2.5c to the 26th .. which is -2.9c below normal 

[Timmytour]

1 hour ago, cheeky_monkey said:

cloudy Edmonton is at 2.5c to the 26th .. which is -2.9c below normal 

Looks like you finish with a flourish though!  :)

 

[cheeky_monkey]

3 minutes ago, Timmytour said:

Looks like you finish with a flourish though! 

 

not really... outside of Thur Fri those are average or slightly below average temps for this time of the year

[Northernlights]

On 25/04/2021 at 23:55, LetItSnow! said:

Even though some have found it rather miserable, I've thoroughly enjoyed what it feels like to go through such an remarkably cooler than average month (especially the minima). Especially since April has been a mild affair pretty much since 1992 bar the odd exception. I hope this is the sign of things like this being more common. This year has a different feel to it, & May is looking to start cool too...

Just for interest my take on the weather we have had since last summer culminating in this Aprils cold.

"In my opinion governments round the world have just witnessed a unique experiment in the last year due to the virus with all forms of transport severely curtailed round the world. (Its great to see the intense colours of the sky with my old eyes and no contrails) This has resulted in the loss of of the brown ring of pollution at the edge of earths atmosphere allowing more heat to be radiated to space. This happened also in the few days after 9/11 when photos from space showed the brown ring of pollution replaced by a white ring. (283,000 aircraft worldwide flying at any one time no longer in the sky)

Also I feel because of this effect we have witnessd more defined seasons in the last year especially up here in the north of Scotland with a superb growing summer, a proper autumn and a winter with the deep cold in January/February. followed by a cold traditional spring as I remember during my childhood in the sixties. Remember the Scottish tenanted farm term date is the end of May in Scotland to allow completion of crop sowing so springs in the past were usually late up here in the last few hundred years.

This I think is the reason that the Biden team are quietly working away to make climate a top priority  with a lot of new research being started. My daughter who has a phd in Astrophysics does not disagree with me. I know this theory will not be popular with the aviation industry but already France has said that virus financial help will have conditions attached. The main one being all internal flights with a train equivalent alternative are to be banned."

 

[Timmytour]

1 hour ago, cheeky_monkey said:

not really... outside of Thur Fri those are average or slightly below average temps for this time of the year

I literally meant the finish, looking at the 30th :)

[Timmytour]

1 hour ago, Northernlights said:

Just for interest my take on the weather we have had since last summer culminating in this Aprils cold.

"In my opinion governments round the world have just witnessed a unique experiment in the last year due to the virus with all forms of transport severely curtailed round the world. (Its great to see the intense colours of the sky with my old eyes and no contrails) This has resulted in the loss of of the brown ring of pollution at the edge of earths atmosphere allowing more heat to be radiated to space. This happened also in the few days after 9/11 when photos from space showed the brown ring of pollution replaced by a white ring. (283,000 aircraft worldwide flying at any one time no longer in the sky)

Also I feel because of this effect we have witnessd more defined seasons in the last year especially up here in the north of Scotland with a superb growing summer, a proper autumn and a winter with the deep cold in January/February. followed by a cold traditional spring as I remember during my childhood in the sixties. Remember the Scottish tenanted farm term date is the end of May in Scotland to allow completion of crop sowing so springs in the past were usually late up here in the last few hundred years.

This I think is the reason that the Biden team are quietly working away to make climate a top priority  with a lot of new research being started. My daughter who has a phd in Astrophysics does not disagree with me. I know this theory will not be popular with the aviation industry but already France has said that virus financial help will have conditions attached. The main one being all internal flights with a train equivalent alternative are to be banned."

 

There is nothing that will ever be said to be "proof" of climate change reversing.

The article below outlines unusual events that have happened in the world that have taken place after a year of air travel reduced to levels last seen in the 1980s.

There is nothing in terms of our climate or weather that is increasing with more intensity than the reporting of it, and the need to associate it with impending disaster.

If the weather events of 1920-1930 had been presented with the same amount of sensationalism as every weather events of the last ten years has been, the idea of climate change rapidly overwhelming the world would have become an easy sell back then at a time when hardly a plane was to be seen in the sky.

My tuppence

Europe's unusually warm week breaks temperature records | Europe | The Guardian

WWW.THEGUARDIAN.COM

---

Mild end to February saw Germany record sharpest temperature rise in a week, going from -23.8C to 18.1C

 

[Roger J Smith]

These CET/EWP threads are probably not the right place to be discussing climate change issues, but surely the amount of change to the atmosphere in this relatively limited economic slowdown is far too little to have this fast an effect on temperature patterns, and it begs the question, why then did we have three notable cold periods (Nov-Dec 2010, Mar-Apr 2013, Aug 2014) back in the full-on airline travel era? I agree it's nice to see a cleaner sky without as much jet contrail debris (there is still some, air travel is down by more than half but it's not zero) but I don't think this unusual April weather pattern has much if anything to do with human activity, a more credible discussion might be where things are at long-term in the aftermath of decades of warming in the arctic. 

Also, I would think while this change in pattern might look good in some places, the farmers and gardeners of southern England probably don't want a cold, dry spring pattern to continue much longer, so it's probably not a good outcome in general. 

Where I live we have had a rather dry April too, but temperatures have been within 1 C of normal and probably a bit above normal (in contrast to Edmonton but then they seem to have slipped into a longer term cooling of their climate).