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

[damianslaw]

Bit of a north-south divide at present, mean temp wise. Much of the CET zone is holding onto well above mean temps, but just north and outside of the zone, average and below average means are occuring.

This weekend sees a continued imbalance, through next week it will be corrected somewhat, with mean temps for all much closer to average.

The exceptional warm first half though, makes it an almost impossible task to return a below average month. Indeed chances of a sub below 16 month are very slim indeed. The question is will Sept 2023 be a record breaker, a very good chance we could finish in the 17s. Unprecedented stuff.. but a late cold spell could put pay to that.. though unlikely given how lively the atlantic looks set to behave. 

[Don]

2 hours ago, damianslaw said:

This weekend sees a continued imbalance, through next week it will be corrected somewhat, with mean temps for all much closer to average.

Thing is though, this week was also supposed to be closer to average for all, but it's ended up being warmer.  If next week follows suit, then surely a record breaking 17C+ month would pretty much be in the bag?

[Earthshine]

12 of the first 14 days of September have all recorded a maximum CET >20°C, impressive!

[Don]

33 minutes ago, Earthshine said:

12 of the first 14 days of September have all recorded a maximum CET >20°C, impressive!

Not sure I'm impressed (I'm horrified!!), but I know what you mean!

I think even you may have gone too low this month, but record breaking months are pretty much impossible to predict!

[summer blizzard]

Euro looks very unsettled and probably not too warm.

[Don]

1 hour ago, summer blizzard said:

Euro looks very unsettled and probably not too warm.

Nothing to really suggest anything that will prevent this month from being exceptionally warm though, i.e. no cold nights to do any damage?

[ItNeverSnowsInWindsor]

I’m not liking the ECM charts which continues to pump warmer air due to the tropical storms.

[The PIT]

Sunny Sheffield still at 18.9C +3.4C above average. Rainfall unchanged at 38.2mm 58.1% of the monthly average.

Big fall for today to come a pause for tomorrow then a steady decline for next week.

[Man With Beard]

I'm thinking it will be a 50/50 call as to whether the CET record is broken. I guess we'll be around the 19C mark at halfway, meaning we'll need to average 15C for the rest of the month to get the record. That won't be exceptionally easy - it's certainly doable, but with an Atlantic driven week coming up next week, I can't see the CET for the period 18th-25th being much in excess of this figure, and it might potentially be below it.

[Addicks Fan 1981]

1 hour ago, Man With Beard said:

I'm thinking it will be a 50/50 call as to whether the CET record is broken. I guess we'll be around the 19C mark at halfway, meaning we'll need to average 15C for the rest of the month to get the record. That won't be exceptionally easy - it's certainly doable, but with an Atlantic driven week coming up next week, I can't see the CET for the period 18th-25th being much in excess of this figure, and it might potentially be below it.

Indeed @Man With Beardand it is achievable.   

[Summer Sun]

19.1c to the 15th

5.6c above the 61 to 90 average
4.4c above the 81 to 10 average

[Derecho]

1 hour ago, Summer Sun said:

19.1c to the 15th

5.6c above the 61 to 90 average
4.4c above the 81 to 10 average

Amazing that we are still above 19C.

However the warmth of this weekend has been downgraded and some cooler weather looks likely later in the week. This makes a record breaking CET challenging now. The GFS 06z OP and EC 00z control end September in the low 16s.

However the remnants of Nigel pose a large degree of uncertainty and the EC 00z control is on the cool side and is actually really quite cold later in the run. So still a lot of uncertainty to iron out. 

[Dancerwithwings]

2 hours ago, Derecho said:

Amazing that we are still above 19C.

However the warmth of this weekend has been downgraded and some cooler weather looks likely later in the week. This makes a record breaking CET challenging now. The GFS 06z OP and EC 00z control end September in the low 16s.

However the remnants of Nigel pose a large degree of uncertainty and the EC 00z control is on the cool side and is actually really quite cold later in the run. So still a lot of uncertainty to iron out. 

Certainly a chance of nightly mid single figures out in the sticks as you mentioned later in the run, if so the CET could drop more than what was on show a few days ago.

[Polarwesterly]

Tropical Storm Nigel will give us a real chance of breaking the September record as it drags up long fetch south westerlies later next week into the following week potentially 

[The PIT]

Sunny Sheffield down to 18.5C +3.1C above average. Rainfall unchanged.

Another drop for today although not as large and a steady drop for next week. Tuesday may not register a drop but no warm days shown for us at the moment.

[Scorcher]

Surprised so many are doubting the chances of the record going- still looks very much on to me.

Atlantic driven weeks won't be that cool in the grand scheme of things- plenty of breeze and cloud cover will hold temps up at night.

This weekend hasn't been downgraded much at all warmth-wise. Maybe not quite as warm for the SE as first thought today, but further north it's actually going to be a bit warmer than expected a couple of days ago.

Last night was another warm night so the CET for today will be high again.

And there is a strong signal for something warmer after this cooler period next week (looks very likely to me). To do believe the last week could end up being very warm CET wise.

[Derecho]

1 hour ago, Scorcher said:

Surprised so many are doubting the chances of the record going- still looks very much on to me.

Atlantic driven weeks won't be that cool in the grand scheme of things- plenty of breeze and cloud cover will hold temps up at night.

This weekend hasn't been downgraded much at all warmth-wise. Maybe not quite as warm for the SE as first thought today, but further north it's actually going to be a bit warmer than expected a couple of days ago.

Last night was another warm night so the CET for today will be high again.

And there is a strong signal for something warmer after this cooler period next week (looks very likely to me). To do believe the last week could end up being very warm CET wise.

The models have become a fair bit warmer then early on yesterday. Looking at this mornings runs the GFS 00z still comes a bit short with a finishing CET of 16.5C.

The EC 00z control is very warm though, notably so for the final week of September, which is coming out with a value of 17.2C! Not far off 1895 there.

The final CET based on the EC control would come out at an impressive 17.5C

I also notice for the early part of this coming week, the EC is warmer then the GFS. Both agree on cool weather to end the week.

Record chances back in play this morning.

On a further note, P14 of the EC is ridiculously warm with the CET finishing at 18.0C

 

Edited September 17, 2023 by Derecho

[Earthshine]

Feeling better about my last-minute 17.2C guess this morning.  When was the last time the highest guess was too low?  Was it December 2015?

[Scorcher]

1 hour ago, Earthshine said:

Feeling better about my last-minute 17.2C guess this morning.  When was the last time the highest guess was too low?  Was it December 2015?

You certainly won't be far off with that guess. I'd say something around the 17C mark is favourite at the moment.

[Earthshine]

23 minutes ago, Scorcher said:

You certainly won't be far off with that guess. I'd say something around the 17C mark is favourite at the moment.

Absolutely incredible to have two 17C+ CET months with neither being July or August.  That would be just just bizarre.

[Summer Sun]

18.9c to the 16th

5.3c above the 61 to 90 average
4.3c above the 81 to 10 average

[Derecho]

5 hours ago, Scorcher said:

This weekend hasn't been downgraded much at all warmth-wise.

Disagree with this, yesterday saw a CET of just 15.6C and temps are widely in the teens at the moment today.

A few days back we were looking at potential means of around 19-20C for Saturday-Monday, its going to be much cooler then that.

[Roger J Smith]

From current 18.9 after 16d, an average of 14.8 or above will produce a new record 17.0 or above. We can get into two decimal tie or 1-2 scenarios if needed. I updated my previous posts containing daily CET values for 2023 and records; will be moving posts into current portion of discussion in a couple of days. We were 0.8 above 1865 previous max running mean (18.9 vs 18.1). It's now closer compared to various days since 2023 overtook leaders 1906 (to 8 Sep) and 1898 (briefly ruled 9-10 Sep) and lead was as great as 2.5 C deg at one point a week ago. Current GFS guidance suggests to me an outcome very close to 16.8 or 16.9, so basically a 50-50 proposition. 

Latest EWP estimate is about 23 mm and  GFS indicates grid average of 55-70 mm more, ending up still near top of our forecast table (92 mm was max forecast). 

 

[Scorcher]

56 minutes ago, Derecho said:

Disagree with this, yesterday saw a CET of just 15.6C and temps are widely in the teens at the moment today.

A few days back we were looking at potential means of around 19-20C for Saturday-Monday, its going to be much cooler then that.

100% not a downgrade for my area.

Stonyhurst is well north of here and is one of the CET stations. Today is warmer there than looked likely 2 days ago.

Edited September 17, 2023 by Scorcher

[Derecho]

9 minutes ago, Scorcher said:

100% not a downgrade for my area.

Stonyhurst is well north of here and is one of the CET stations. Today is warmer there than looked likely 2 days ago.

More of a case compared to 5-7 days ago when we had a warm SE wind covering the UK. Temps this weekend were widely expected to reach the mid-high 20s across England lasting till Monday. However it became a much messier picture with the warmth restricted to SE England only yesterday. Today I think will come in around the low 17s whereas tomorrow should be in the 14s.

Edited September 17, 2023 by Derecho