December 2023 C.E.T. and EWP forecast contests -- start of 2023-24 contest year -- all welcome

[snowray]

1 hour ago, Scorcher said:

I think the question might have been whether there has been a 7.0C month on the button- which there hasn't. Plenty of 7C+ Decembers though yes.

Looks like there has never been a 7c or a 7.1c December in 300 odd years, but quite a few milder ones, notably in the 1800's. I just thought it looked a bit strange. 

[Roger J Smith]

8 hours ago, TheOgre said:

How warm does this month need to be for 2023 to be warmer than 2022?

About 7.5 to 7.7, their protocol in calculating annual average is not as simple as just adding twelve values and dividing by 12, it is probably based on an average of mean daily maxima and mean daily minima, but it appears we will fall a bit short although I think there's a chance that 2023 will at least tie 2022 in one decimal (at 11.1 C for CET). They rank years and months based on a second decimal which is not in the tables. 7.6 would give the same total for the twelve months. 

[Summer Sun]

7.0c to the 29th

2.5c above the 61 to 90 average
2.5c above the 81 to 10 average

[Metwatch]

Just realised that despite March and December both having a mild CET of 7.0C they also brought some decent falls of snow here. So even with above average CET months, many down to central England could in theory scrap a snow event though usually not a given. So if a winter month is near even the 1991-2020 average then it's more likely you will snow, but then even more so with the colder 61-90 average!

Edited December 30, 2023 by Metwatch

[WYorksWeather]

11 hours ago, Roger J Smith said:

About 7.5 to 7.7, their protocol in calculating annual average is not as simple as just adding twelve values and dividing by 12, it is probably based on an average of mean daily maxima and mean daily minima, but it appears we will fall a bit short although I think there's a chance that 2023 will at least tie 2022 in one decimal (at 11.1 C for CET). They rank years and months based on a second decimal which is not in the tables. 7.6 would give the same total for the twelve months. 

Using the HadCET tracker, the anomaly to yesterday is 1.62C, and last year's was 1.68C. That would imply 11.09C as where we would currently finish, based on 11.15C last year.

Somewhat under the radar, but right at the end of the year, it does look like 2023 will just about break the record for minimum CET. We're currently at an anomaly of 1.39C, which would imply a finish of 7.24C, tied on 7.2C in one decimal but breaking the record in two decimal places. However, if we get enough in the last couple of days for another tick up to 7.25C (truncated, rather than rounded), then we'd have a clear record break in one decimal, with a new record high of 7.3C.

[TillyS]

14 minutes ago, Summer Sun said:

7.0c to the 29th

 

Any thoughts folks where it might finish? A cool-ish night but followed by mild today in the bottom half of the CET zone. Then mild tonight/tomorrow.

So I’m reckoning 6.9C or 7.0C ?

[WYorksWeather]

4 minutes ago, Metwatch said:

Just realised that despite March and December both having a mild CET of 7.0C they also brought some decent falls of snow here. So even with above average CET months, many down to central England could in theory scrap a snow event though usually not a given. So if a winter month is near even the 1991-2020 average then it's more likely you will snow, but then even more so with the colder 61-90 average!

Yep, because a short cold snap doesn't have that big an influence on the CET. If you have a seven day period that is even 5C below the 1961-1990 (which would be very cold with sub-zero CET means), and then the rest of the month is mild but not outrageously so in modern terms (say 2C above 1961-1990), then in a 30-day month you'd finish at (-5 * 7 + 2 * 23) / 30 = 0.4C above 1961-1990.

I think it's quite possible that even if we do get a colder than average spell in January that goes on for quite some time, we might still end up with an above average month overall, because as I've been saying over on the model thread for some weeks now, the sea near the Azores is so anomalously warm that any long-fetch south-westerly will be very mild, so it doesn't take much of that to erase a cold spell from the CET average.

[WYorksWeather]

6 minutes ago, TillyS said:

 

Any thoughts folks where it might finish? A cool-ish night but followed by mild today in the bottom half of the CET zone. Then mild tonight/tomorrow.

So I’m reckoning 6.9C or 7.0C ?

Just did some quick maths on this and to two decimals we're at 7.02C. To finish at 6.9C, we'd need lower than 6.95C in two decimals, which would need the last two days to finish (by my estimate) at something like 5.5C or lower. That seems a little unlikely to be honest, so I think it will finish at 7.0C rounded, though possibly below 7.0C unrounded.

 

[Addicks Fan 1981]

52 minutes ago, WYorksWeather said:

Just did some quick maths on this and to two decimals we're at 7.02C. To finish at 6.9C, we'd need lower than 6.95C in two decimals, which would need the last two days to finish (by my estimate) at something like 5.5C or lower. That seems a little unlikely to be honest, so I think it will finish at 7.0C rounded, though possibly below 7.0C unrounded.

 

Think another 11 degree year is on the cards now to be honest with you.   Think this is actually pretty worrying and a red flag for our future climate because 2022 wasn't all by itself as its turned into being a trendsetter.    

[damianslaw]

My December guess went down the pan.. didn"t expect it to be quite so mild. It has been a very poor month other than the cold snowy opening, second half up there with mildest on record and persistantly wet reminding me of 2013, 2015, 2021 and indeed last year. The last three christmas periods have been exceptionally wet and mild, just grim. 

[Optimus Prime]

4 hours ago, Addicks Fan 1981 said:

Think another 11 degree year is on the cards now to be honest with you.   Think this is actually pretty worrying and a red flag for our future climate because 2022 wasn't all by itself as its turned into being a trendsetter.    

2014 is also part of the 11+ club. Question is how long until 11.0 C becomes the norm. Probably by 2050.

[WYorksWeather]

4 hours ago, Addicks Fan 1981 said:

Think another 11 degree year is on the cards now to be honest with you.   Think this is actually pretty worrying and a red flag for our future climate because 2022 wasn't all by itself as its turned into being a trendsetter.    

An 11C year is now guaranteed, won't even be that close. Could even finish at 11.1C.

[WYorksWeather]

10 minutes ago, Optimus Prime said:

2014 is also part of the 11+ club. Question is how long until 11.0 C becomes the norm. Probably by 2050.

Only rounded - in two decimals it finished at 10.98C, so last year was the first 'true' 11C year.

In terms of how long it will take to become the norm it really depends on how you define, if we take the current norm to be something near 10.5C as an average, I think 2050 is overly optimistic. The current background warming rate is 0.2C per decade, but the UK is on land (obviously) and at relative high latitude, which increases the warming rate, most likely to 0.3C or 0.4C per decade. I think if you used five years either side of 2040 you might well find a majority over 11C, and one or two at 11.5C or higher.

If you mean the norm as in 'almost every year, except the very cool ones' (e.g. where we are with 10C now, which has only been missed four times this century), then I'd be more inclined to agree with 2050.

 

[Roger J Smith]

NYC also will have its highest annual average, probably 14.5 C and that is a full 0.4 above previous records of 14.1 in 2012 and 2020. But its highest reading of the year was only 93F (34 C) and only 10% of years had a lower annual max. So it was a bland sort of warmth almost entirely devoid of colder than average spells, and anchored by very mild winter averages at both ends of 2023. January was warmest on record, and this December looks like it will be second warmest (to 2015); February was also in top ten. November did see some below average readings and ended up below 1991-2020 average although near longer-term average. 

NYC period of record is 1869 to present ... Toronto with 184 years of data will end up near 5th warmest year or t4 possibly ... like NYC they had a very mediocre summer max of 91F or 32.9 C in early September. Both were 3C deg below long-term averages for that statistic (NYC 37 C and Toronto 36 C). 

Edited December 30, 2023 by Roger J Smith

[BlueSkies_do_I_see]

3 hours ago, WYorksWeather said:

Only rounded - in two decimals it finished at 10.98C, so last year was the first 'true' 11C year.

In terms of how long it will take to become the norm it really depends on how you define, if we take the current norm to be something near 10.5C as an average, I think 2050 is overly optimistic. The current background warming rate is 0.2C per decade, but the UK is on land (obviously) and at relative high latitude, which increases the warming rate, most likely to 0.3C or 0.4C per decade. I think if you used five years either side of 2040 you might well find a majority over 11C, and one or two at 11.5C or higher.

If you mean the norm as in 'almost every year, except the very cool ones' (e.g. where we are with 10C now, which has only been missed four times this century), then I'd be more inclined to agree with 2050.

 

3 out of every 5 years, will be averaging 11C from now on. Quote me on here and tell me I was wrong in 2028.

[WYorksWeather]

2 hours ago, BlueSkies_do_I_see said:

3 out of every 5 years, will be averaging 11C from now on. Quote me on here and tell me I was wrong in 2028.

Yeah I suppose it's not out of the question that we might get a majority in the 2021-2030 decade. Possibly things are moving fast enough that my suggestion that the underlying 'norm' is 10.5C might already be too low. I'm far from convinced that you are wrong, I'll just say that I hope you're wrong.

[Daniel*]

Surprising just how mild it has been, if we remove 2015 it would be a record!

[Summer Sun]

7.0c to the 30th

2.5c above the 61 to 90 average
2.5c above the 81 to 10 average

[Roger J Smith]

By looks of today's reported max and min, CET will stay on 7.0 (I expect today to report around 6.5 to 7.0). 

EWP was already 140.6 mm before yesterday's downpours and will likely end up near 160 mm. It will be very close to passing 1960 for 6th place (162 mm would be required) in annual precip. 

All of the above means that the scoring table posted back in thread is quite accurate and can be brought forward tomorrow. EWP errors will require an edit but not points scoring portion. 

A happy new year to all, don't forget to enter January 2024 contest.

[The PIT]

Sunny Sheffield finished on 6.4C +1.6C above average. Rainfall 166.3mm 190.1% of the monthly average. The 4th wettest on record.

The year as a whole the warmest on record at 11.1C and the 2nd wettest on record with 1179.6mm  Just 30.2mm shy of breaking the 2012 record.

[TillyS]

They said on the BBC Meteo Group forecast this morning that December was the dullest on record.

Fits with remarks made on this site about the weather.

[Roger J Smith]

Confirmed at 7.0, and they show 2023 in second place (annual CET) but tied w2022 in one decimal at 11.1 C. 

[Addicks Fan 1981]

Just now, Roger J Smith said:

Confirmed at 7.0, and they show 2023 in second place (annual CET) but tied w2022 in one decimal at 11.1 C. 

Not being funny now @Roger J Smithas climate change is now pretty serious.   Even if we have a cooler year than last year we are still very much in a warming trend.    

[Frigid]

4 minutes ago, Roger J Smith said:

Confirmed at 7.0, and they show 2023 in second place (annual CET) but tied w2022 in one decimal at 11.1 C. 

2023 is basically 2022 without the extremes. No extreme heat, no extreme cold. Incredible how the yearly CET is basically the same.

I do wonder if we'll ever see a year in the 9s, an incredible feat these days. Thought 2021 could be the one, but of course the second half was mild. A 10-10.5C year will be decidedly cool from now on, given we've seen two 11C years back to back.

Edited January 1 by Frigid

[Addicks Fan 1981]

Just now, Frigid said:

2023 is basically 2022 without the extremes. No extreme heat, no extreme cold. Incredible how the yearly CET is basically the same.

I do wonder if we'll ever see a year in the 9s, an incredible feat these days. Thought 2021 could be the one, but of course the second half was mild. 

It's unprecedented that June and September were the joint warmest months of the year.  Never happened before.