April 2023 C.E.T. and EWP contests

[Roger J Smith]

 

April CET extremes and 1981-2010 averages, extreme values of running CET

 

NOTE: All temperature data now converted to v2.0. 

 

DATE ___ MAX yr _________ MIN yr ____________ CET __cum CET ____ Max CET __ Min CET

01 Apr ... 13.4 (1995) ........--0.0 (1799&1917) __8.3 _____ 8.3 ____ 13.4 (1995) __--0.0 (1799&1917)
02 Apr ... 13.9 (1835) ........--0.4 (1917) _________8.1 _____ 8.2 ____ 13.2 (2011) __--0.2 (1917)

03 Apr ... 15.0 (1946) ........ --0.5 (1799) _______7.4 _____ 7.9 ____ 12.9 (1946) __  0.0 (1917)
04 Apr ... 15.6 (1946)......... 1.0 (1809&1830) ___ 7.1 _____ 7.7 ____ 13.6 (1946) __ 0.5 (1799)
05 Apr ... 13.2 (1857) ......... 0.5 (1911) _________ 7.1 _____ 7.6 ____ 12.8 (1926,46)__1.2 (1917)

06 Apr ... 15.2 (2011) ......... 0.8 (1911) _________ 7.5 _____ 7.6 ____ 12.6 (1926) __ 1.4 (1917)
07 Apr ... 14.7 (1859) ......... 1.0 (1839) _________ 7.3 _____ 7.5 ____ 12.4 (1926) __ 1.7 (1917)
08 Apr ... 13.1 (2020) ......... 2.4 (1780) _________ 7.2 _____ 7.5 ____ 12.0 (1926) __ 2.1 (1917)
09 Apr ... 13.8 (2017) ......... 1.4 (1812) _________ 7.5 _____ 7.5 ____ 11.8 (2011) __ 2.2 (1917)
10 Apr ... 14.1 (2020) ......... 0.5 (1837) _________ 8.2 _____ 7.6 ____ 11.8 (2011) __ 2.1 (1917)

11 Apr ... 15.9 (1869) ......... 1.3 (1978) _________ 8.1 _____ 7.6 ____ 11.8 (2011) __ 2.2 (1917)

12 Apr ... 14.5 (1939) ......... 1.1 (1879) _________ 7.8 _____ 7.6 ____ 11.5 (2011) __ 2.3 (1917)
13 Apr ... 14.6 (1792) ......... 1.1 (1816) _________ 7.5 _____ 7.6 ____ 11.2 (1778,2011)__2.4 (1917)
14 Apr ... 15.9 (1869) ......... 0.5 (1966)*_________8.0 _____ 7.7 ____ 11.1 (2011) __ 2.5 (1917) _ *(also 0.6 1816)
15 Apr ... 16.3 (1945) ......... 1.5 (1966) _________ 8.3 _____ 7.7 ____ 11.1 (2011) __ 2.6 (1917)

16 Apr ... 17.1 (1945) ......... 2.2 (1837&1892) ___8.6 ____ 7.8 ____ 11.1 (2011) __ 2.8 (1917)
17 Apr ... 14.8 (1865&2003) .. 2.1 (1793&1812) _ 8.4 ___7.8 ____ 11.1 (2011) _ 2.8 (1917)
18 Apr ... 17.0 (2018) ......... 1.7 (1807) _________ 8.1 _____ 7.8 ____ 11.2 (1945) __ 3.0 (1837,1917)
19 Apr ... 17.7 (2018) .........--0.2 (1772) _________8.2 _____ 7.8 ____ 11.4 (1945) __ 3.2 (1837)
20 Apr ... 16.7 (1893) ......... 2.3 (1849) _________ 8.4 _____ 7.9 ____ 11.5 (1945) __ 3.3 (1837)

21 Apr ... 15.8 (1893) ......... 2.4 (1936) _________ 9.2 _____ 7.9 ____ 11.6 (2011) _ 3.3 (1837)
22 Apr ... 15.4 (2011) ......... 3.4 (1778) _________ 9.4 _____ 8.0 ____ 11.7 (2011) __ 3.5 (1837)
23 Apr ... 15.9 (2011) ......... 2.5 (1908) _________ 9.7 _____ 8.1 ____ 11.9 (2011) __ 3.6 (1837)
24 Apr ... 15.4 (2007) ......... 0.6 (1908) _________ 9.7 _____ 8.1 ____ 12.0 (2011) __ 3.7 (1837)
25 Apr ... 15.9 (1821) ......... 1.8 (1908) ________ 10.1 _____ 8.2 ____ 12.0 (2011) __ 3.9 (1837)

26 Apr ... 15.9 (1821) ......... 3.4 (1981) ________ 10.1 _____ 8.3 ____ 11.9 (2011) __ 4.1 (1837)
27 Apr ... 16.3 (1866) ......... 2.8 (1919) ________ 10.1 _____ 8.4 ____ 11.9 (2011) __ 4.2 (1837)
28 Apr ... 16.9 (1775) ......... 3.0 (1826) _________ 9.9 _____ 8.4 ____ 11.8 (2011) __ 4.4 (1837)
29 Apr ... 19.7 (1775) ......... 0.7 (1856) _________ 9.9 _____ 8.5 ____ 11.8 (2011) __ 4.5 (1837)
30 Apr ... 17.4 (1775) ......... 2.7 (1945) ________ 10.5 _____ 8.5 ____ 11.9 (2011) __ 4.7 (1701&1837)*

* Min CET on 30th from monthly averages, no daily data for 1701 otherwise. 

===========================================================================

1991-2020 CET daily averages and running means

1 __ 8.3 _ 8.3 ___ _ 6 __ 8.4 _ 8.2 ___ _ 11 __ 8.4 _ 8.2 ______ 16 __ 8.6 _ 8.3 ___ _ 21 __10.0 _ 8.5 ___ _ 26 __10.0 _ 8.8

2 __ 8.6 _ 8.5 ___ _ 7 __ 8.0 _ 8.1 ___ _ 12 __ 8.3 _ 8.3 ______ 17 __ 8.8 _ 8.3 ___ _ 22 __10.2 _ 8.5 ___ _ 27 __ 9.8 _ 8.9

3 __ 8.0 _ 8.3 ___ _ 8 __ 8.1 _ 8.1 ___ _ 13 __ 7.8 _ 8.2 ______ 18 __ 8.6 _ 8.3 ___ _ 23 __10.5 _ 8.6 ___ _ 28 __ 9.7 _ 8.9

4 __ 7.7 _ 8.2 ___ _ 9 __ 8.5 _ 8.2 ___ _ 14 __ 8.4 _ 8.2 ______ 19 __ 8.8 _ 8.3 ___ _ 24 __10.6 _ 8.7 ___ _ 29 __ 9.8 _ 8.9

5 __ 8.0 _ 8.1 ___ _10__ 8.7 _ 8.2 ___ _ 15 __ 8.6 _ 8.3 ______ 20 __ 9.2 _ 8.4 ___ _ 25 __10.6 _ 8.8 ___ _ 30 __10.3 _ 9.0 (8.97)

 

 

[Roger J Smith]

Old records eventually fall ... but the three day warm spell at the end of April 1775 is quite remarkable and you wonder when that (or any of its three records) might go. By the way, there are no close calls lurking behind the daily records, although the 16.3 on 29th 1828 and 16.8 on 30th 1827 are (were) probably not previously known to many; the highest values for 28th to 30th other than 1775 are 

28th __ 15.4 (1994)

29th __ 16.3 (1828)

30th __ 16.8 (1827)

 

[Summer Sun]

8.3c to the 1st

0.4c above the 61 to 90 average
Bang on the 81 to 10 average

[ItNeverSnowsInWindsor]

Should see a nice drop in the coming days. Gonna need it to counteract the usual mild finishes we’ve seen!

[Roger J Smith]

GFS suggesting a very dry start with the small amounts of 1st (not yet available on tracker but looks to be 3-5 mm) added to about 5 mm at most by 18th. If that happens, every forecast will be in play and will be fully dependent on the rainfall 19th-30th. 

The CET indications are about average, some mild spells and some colder days in the mix, looks to be heading for about 7.5 to 8.5 by mid-month. Again, most forecasts would be in play and dependent on what happens after the 18th. Despite two very warm Aprils this century, most of the daily records in April seem to be a long way back and half of them are from before 1894. Other than 1939, 1945 and 1946 there are no other years with record daily high means between 1894 and 1994 inclusive. This past two decades have seen a return of some from 2007, 2011 and 2018. 

The last time a daily low mean was set was in April 1981, and before that it had been 1978, 1966, then back to 1945, 1936, 1919, 1917, 1911 and 1908 with all of the other record low means before 1880 except for a tie in 1892. Even so there are more record low means in the 20th century in April than in any other month although February is close and similar in percentages.

In v2.0, 1901-2000 has the following number of record low mean daily values (counting ties as 0.5 or 0.33) and in brackets the number in the 21st century (2001-23) ...

NUMBER of RECORD LOW DAILY CET MEANS in 20th CENTURY (and 21st)

APR __ 13.5 (0)

FEB __ 12.5 (0)

NOV __ 10.0 (1) __ incl 2 x 0.5

JUN __ 9.33 (0) __ incl 2 x 0.5

AUG __ 8.5 (0)

JUL ___ 7.5 (0)

MAY __ 7.0 (0)

JAN ___ 6.0 (0)

SEP ___ 5.5 (0)

MAR __ 5.0 (1)

DEC __ 4.5 (3)

OCT __ 1.0 (0)

A total of 90.33 records set in 20th century and 5 in 21st century (four of those in late 2010).

There were no record low means in 1900 or 2000 so it doesn't matter how you define 20th and 21st centuries. 

At random in 251 years there should be 148 records in a full century and about 34 at this point in the 21st century.

 

[stewfox]

Probably too late but 9c and 77mm

[Summer Sun]

8.4c to the 2nd

0.5c above the 61 to 90 average
0.2c above the 81 to 10 average

[Roger J Smith]

6 hours ago, stewfox said:

Probably too late but 9c and 77mm

Not too late, entries close at midnight. 

[damianslaw]

April set to start on a fairly average note, maxima probably a bit above average but cancelled out by slightly below average minima. Nothing particularly mild on the way but many will no doubt by easter weekend remark on how warm it feels, inevitable and understandable as the sun by now has the same strength as early September, and that's 7 months ago!

[Summer Sun]

7.5c to the 3rd

0.4c below the 61 to 90 average
0.4c below the 81 to 10 average

[Daniel*]

19 hours ago, damianslaw said:

April set to start on a fairly average note, maxima probably a bit above average but cancelled out by slightly below average minima. Nothing particularly mild on the way but many will no doubt by easter weekend remark on how warm it feels, inevitable and understandable as the sun by now has the same strength as early September, and that's 7 months ago!

Well below average minima this morning.

 

[Metwatch]

20 minutes ago, Daniel* said:

Well below average minima this morning.

 

CET minimum still not overly anomalous, however after this morning I suspect we'll see another drop for tomorrow's value. 

Edited April 4, 2023 by Metwatch

[matty40s]

A 5am -3.4 upnto a 16.6 an hour ago is quite a remarkable spread here!!

[Roger J Smith]

EWP has only 1 mm to show so far, and by the 20th is barely up to 20 mm on GFS 06z guidance. The CET would likely remain in a similar range for the week ahead, possibly losing a bit of ground, then rising slowly towards mid-month. Would expect it to be not far from 8 to 8.5 C by 20th on current guidance. 

[Summer Sun]

7.2c to the 4th

0.7c below the 61 to 90 average
0.5c below the 81 to 10 average

[Metwatch]

23 hours ago, Metwatch said:

CET minimum still not overly anomalous, however after this morning I suspect we'll see another drop for tomorrow's value. 

And indeed it has, with a value of 2.8°C up to yesterday. On the rise from tomorrow though. 

[damianslaw]

CET values set close to or just a little above average for the next week or so, the drier finer conditions will bring cool minima and higher maxima, conversely the wetter days milder minima and cooler maxima such as happened today - both cancelling themselves out. All quite average.

Edited April 5, 2023 by damianslaw

[Summer Sun]

7.3c to the 5th

0.6c below the 61 to 90 average
0.3c below the 81 to 10 average

[The PIT]

Sunny Sheffield at 6.5C  -0.4C below average. Rainfall 10.8mm 19.3% of the monthly average.

[damianslaw]

A small rise expected in the days ahead, minima will hold things down somewhat,  I suspect we will be very close to the mean by mid month point, may be just slightly above. Will we see another very mild latter end to the month as happened in Dec, Jan, Feb (lesser extent) and March..

[Roger J Smith]

EWP probably around 11-12 mm, and GFS says it will add 25-30 mm to 23rd. (36-42 mm). This is just slightly below a normal pace for April. 

If you missed my late post in the March thread, March ended up in third place after all at 136.8 mm. 

[Summer Sun]

7.8c to the 6th

0.1c below the 61 to 90 average
0.2c above the 81 to 10 average

[The PIT]

Sunny Sheffield 6.5C -0.5C below average. Rainfall 10.8mm 19.3% of the monthly average.

[The PIT]

Sunny Sheffield up to 7.3C  -0.2C below average. Rainfall unchanged at 10.8mm 19.3% of the monthly average.

[Summer Sun]

7.8c to the 7th

0.1c below the 61 to 90 average
0.3c above the 81 to 10 average