September 2023 C.E.T. and EWP forecast contests

[Roger J Smith]

The CET contest already gives bonus points for accuracy so I don't think we'll see any push for bonus points for records, two out of four of the top forecasts will also separate by not taking late penalties. In any case both contests are scored in such a way that best forecast scores 100 (CET) or 10.0 (EWP) and so the scoring details are down to differentials below those fixed top values, you won't see any change to top scoring so any tweaking of scoring would occur in the points differentials below those. 

Also Dec 2015 if anyone predicted 10.0 it was not in our contest, I have looked back at that to answer questions in the past about predictions in very warm months, and famously Lettucing Gutted had a rare too-low forecast of 9.0 to win that month. I went out on a limb and said 7.5. All these threads are back in the dusty corridors of pages x to 200 of this forum, but here's a mystery I was trying to solve, looking back I can find every month except Jan 2007 and I have tried a number of searches including keywords and username posts, but I never find that contest thread and I'm wondering if it got placed in a different forum? Is it possible to search all of our posts from fifteen to twenty years ago? I was going to post a list of monthly contest winners but have been stalled in that project by the missing Jan 2007. (before that, these contests appear to have started in winter 2005-06). 

Annoying that there are no updates available for CET, I figure it will finish on 17.0 but 16.9 or 17.1 are possible. EWP looks to be 88-92 mm, will update tomorrow and confirm on 2nd (for now, 5th Oct for final table value). 

 

[Derecho]

34 minutes ago, Roger J Smith said:

 

Also Dec 2015 if anyone predicted 10.0 it was not in our contest, I have looked back at that to answer questions in the past about predictions in very warm months, and famously Lettucing Gutted had a rare too-low forecast of 9.0 to win that month.

 

That was it, I remember they went for an absurdly high guess that was actually the best one that month.

[Daniel*]

8 hours ago, Derecho said:

Seems likely, only Rothamstad got into single figures this morning as well so the GFS from a few days ago went too low.

Wrong 

 

[Derecho]

19 minutes ago, Daniel* said:

Wrong 

 

Bear in mind the CETs I've calculated are based on the midnight to midnight values and the lowest temperatures last night came in later in the morning of the 30th (Rothamstad actually dropped below 10C after midnight anyway).

The hourly obs at Pershore don't tally up well with the above as the lowest min was 10.3C at 06:00, unless there was a further drop between the hourly recordings? 

Weatherobs

WEATHEROBS.COM

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Global weather observations (METAR, SYNOP, BUOY, SHIP, TAF, CWOP) decoded to enable display of latest temperatures, weather, snow depths, precipitation, wind and wave conditions and more

Edited September 30, 2023 by Derecho

[Derecho]

9 hours ago, The PIT said:

Sunny Sheffield still at 16.7C +2.6C above average. Rainfall unchanged.

Looks like we will finish on 16.6C beating the previous record of 16.3C recorded in 2001.

I presume that was 2006 and not 2001? 2001 was a pretty average September over the UK overall.

[Don]

49 minutes ago, Derecho said:

I presume that was 2006 and not 2001? 2001 was a pretty average September over the UK overall.

Yes, September 2001 was very average, followed by the record breaking warm October, where I think some regions were warmer than September?

Edited September 30, 2023 by Don

[The PIT]

1 hour ago, Derecho said:

I presume that was 2006 and not 2001? 2001 was a pretty average September over the UK overall.

Yup 2006 typo on my part

[Summer Sun]

September was warmer than any of the 3 summer months in the UK

 

[Man With Beard]

6 minutes ago, Summer Sun said:

September was warmer than any of the 3 summer months in the UK

 

Appears to confirm CET must have been at least 17.0C as it is given as higher than June's?

[Don]

4 minutes ago, Man With Beard said:

Appears to confirm CET must have been at least 17.0C as it is given as higher than June's?

I think the likely September CET figure will be 17.1C?

[mr.splinter]

20 minutes ago, Summer Sun said:

September was warmer than any of the 3 summer months in the UK

 

The article quoted in the tweet is two days old.

[rwtwm]

20 minutes ago, Man With Beard said:

Appears to confirm CET must have been at least 17.0C as it is given as higher than June's?

Not necessarily, as they often use UK wide figures rather than CET for Met Office press releases.

Seems likely it was though.

[Roger J Smith]

EWP tracker ended 91.0 mm, will pause updates to scoring to 5 Oct for final table value (current scoring was based on 90 and no points would be adjusted, only average errors very small corrections). 

I am guessing CET will end on 17.0, but we must wait for confirmation. 

[MattStoke]

14 hours ago, Summer Sun said:

September was warmer than any of the 3 summer months in the UK

 

Made more impressive by the fact June was the warmest on record by quite a wide margin.

[BruenSryan]

15 hours ago, rwtwm said:

Not necessarily, as they often use UK wide figures rather than CET for Met Office press releases.

Seems likely it was though.

Simon King is referring to the CET. A bit of a misleading article though to use the CET as a representation of the whole UK in the title and coming to that conclusion a few days early.

On the UK mean temp, September was cooler than both June and August but warmer than July. 

[BruenSryan]

I was informed that the lack of staff and resources is likely why the CET has been poor at getting updates the past week according to Dan Harris who is a Met. Annoying but at least there's a possible known reason why this has been the case.

[Polarwesterly]

30 minutes ago, BruenSryan said:

I was informed that the lack of staff and resources is likely why the CET has been poor at getting updates the past week according to Dan Harris who is a Met. Annoying but at least there's a possible known reason why this has been the case.

Nice to hear from you again bruensryan. It was all very close between them 4 months for the uk as a whole. All around the low 15’s

 

edit: just realised June was significantly warmer near 16c

Edited October 2, 2023 by Polarwesterly

[BruenSryan]

It has now finally been released.

September 2023 CET was equal to June (at least to one decimal point, I'm sure others will tell us how close it was with multiple decimal points) with 17.0C. Warmest ever recorded.

Edited October 2, 2023 by BruenSryan

[Frigid]

This looks.. so bizarre.

Fair play to September, if it's going to be warm.. might as well make it stand out. Same CET as the record breaking June, madness. 

[Derecho]

40 minutes ago, BruenSryan said:

It has now finally been released.

September 2023 CET was equal to June (at least to one decimal point, I'm sure others will tell us how close it was with multiple decimal points) with 17.0C. Warmest ever recorded.

Nice, with the latest output you have to wonder where October will end up. Could we end up with consecutive record breaking monthly CETs? Still very early days at this point of course.

Edited October 2, 2023 by Derecho

[Stationary Front]

Just to be clear, if talking about the CET, then June 2023 is the 5th highest at 17.0c, there are 4 previous June’s higher than 17.0c. September 2023 is indeed the highest recorded in the CET series. 

[Scorcher]

I did say that I expected 17.0C a few days back when others were convinced it was going to drop into the 16s. Just shows you shouldn't trust the raw data from the GFS, which is often too low.

It surprises me how many very knowledgeable people in here trust the GFS in situations like that. The same thing happened in June when some were convinced it was going to go below 17.0C a few days before the end of the month.

A really remarkable month- particularly in the south when you look at the number of days that reached 20C+ across the month. Heathrow only had 5 days across the month that failed to reach 20C and a lowest maximum temperature of 18.6C. And the heatwave in the first 10 days was something that will live long in the memory for most of us across the country.

Edited October 2, 2023 by Scorcher

[cheese]

1 hour ago, Frigid said:

This looks.. so bizarre.

Fair play to September, if it's going to be warm.. might as well make it stand out. Same CET as the record breaking June, madness. 

Just bizarre for neither July or August to be the warmest month. July relegated to 4th warmest!

Edited October 2, 2023 by cheese

[Metwatch]

1 hour ago, Frigid said:

This looks.. so bizarre.

Fair play to September, if it's going to be warm.. might as well make it stand out. Same CET as the record breaking June, madness. 

Incredible really that this is the second time in recorded history that September has been the warmest month of the year by the CET. June CET 16.96C, September 17.00C to 2 decimal places.

1890 was the only case but no months that year were above 15C, meanwhile this year all above 16C!

1890 CET's:

June: 13.5C

July: 14.5C

August: 14.1C

September: 14.6C

[BlueSkies_do_I_see]

It's happened because of a couple of things:

 As a planet we just  experienced the warmest two months ever recorded, back to back.  July 2023 warmest ever recorded, August 2023 2nd warmest ever recorded. June 2023 was the 8th warmest.

We got lucky /unlucky (depending on your weather preference) during July and August by avoiding seeing that heat dome migrate north.

It didn't go away though - we just finally tapped into it, just as August turned to September. Given the timing, it maxed out our stats for the month.