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

[Don]

1 minute ago, Earthshine said:

Correlation doesn't equal causation.  I wouldn't give much notice to potential "trends", particularly when we have so few 16°C+ Septembers.  With such a small dataset it's bad science to draw any conclusions about what the following winter will do.  

This is true, but I would still rather not have a notably warm September being a cold winter lover!  However, I would recommend watching Gavin's latest winter update as it also covers those September's followed by cold winters.

[Earthshine]

Just now, Don said:

This is true, but I would still rather not have a notably warm September being a cold winter lover!  However, I would recommend watching Gavin's latest winter update as it also covers those September's followed by cold winters.

Hey, I'm going to enjoy any last burst of summer before the long, grey and cold season that is the British winter. I wouldn't worry too much at this point in time, winter is a long old affair in Britain and I'm sure we'll have at least some cold weather (although seeing the state of winters in recent years, I may have to retract that statement ).

[LetItSnow!]

I’ve always been sceptical of those types of forecasts anyway. I really don’t believe that things like a small window of rainfall or temperature or how the autumn pattern is have much to do with anything with how the following winter will pan out, but that’s just my opinion. 

In terms of this September, did not see it coming! But caution to those who think 16+ is nailed on, it’s definitely not. September is a cooling time of year and any northerly snap late in the month + downwards corrections could see us dip, but regardless of that, it’s very most likely coming out warmer than average. The question is how much?  

Only last year September tricked us with its warm first half…

[Derecho]

An above average September is nailed on I think, though a chilly northerly at the end of the month could send the CET into the 15s. I went too low with my guess unless we get a very chilly second half to the month.

[Summer Sun]

18.2c to the 11th

3.7c above the 61 to 90 average
3.2c above the 81 to 10 average

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Current high this month 18.1c on the 10th & 11th
Current low this month 14.4c on the 1st

[The PIT]

Sunny Sheffield down to 17.6C +1.8C above normal. Rainfall 5.1mm 7.8% of the monthly average.

[Summer Sun]

17.9c to the 12th

3.5c above the 61 to 90 average
2.9c above the 81 to 10 average

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Current high this month 18.1c on the 10th & 11th
Current low this month 14.4c on the 1st

[Roger J Smith]

EWP projections were a bit higher on the weekend but have settled back to a more gradual increase on the latest 12z GFS, 11 mm to 12th and then an average of about 15 mm (heavier in parts of the east Midlands) to the 23rd; not much indicated after that on the latest run but high uncertainty given the time frame, so basically we seem good for at least 30 mm but possibly more like 40-50 if some rain is added at the end. 

The temperature trend is very warm almost all the time, and while it will obviously have to come down a bit there's no obvious reason why it would get below 16 with a warm blocking pattern indicated near the end of the month. 

[The PIT]

Sunny Sheffield down to 17.5C +1.8C above normal. Rainfall 5.8mm 8.8% of the monthly average.

[Summer Sun]

17.7c to the 13th

3.4c above the 61 to 90 average
2.8c above the 81 to 10 average

___________________________

Current high this month 18.1c on the 10th & 11th
Current low this month 14.4c on the 1st

[LetItSnow!]

A quick look at the models shows a cooler outlook into the second half of September than what has been seen so far. One to watch out for as that will pummel the CET figure into the 14s or 15s. I’m not too confident of a 15.5-16.0+ finish now but output could change. It’s nice to see the onset of autumn though. Once mid-September arrives I lose interest in hot weather. We’ll see if this trend continues. 

[Don]

25 minutes ago, LetItSnow! said:

A quick look at the models shows a cooler outlook into the second half of September than what has been seen so far. One to watch out for as that will pummel the CET figure into the 14s or 15s. I’m not too confident of a 15.5-16.0+ finish now but output could change. It’s nice to see the onset of autumn though. Once mid-September arrives I lose interest in hot weather. We’ll see if this trend continues. 

Lets hope so and if the CET is kicked back into the 14's, my guess of 14.5C will be in with a chance!

[Summer Sun]

17.6c to the 14th

3.3c above the 61 to 90 average
2.8c above the 81 to 10 average

___________________________

Current high this month 18.1c on the 10th & 11th
Current low this month 14.4c on the 1st

[Scorcher]

21 hours ago, LetItSnow! said:

A quick look at the models shows a cooler outlook into the second half of September than what has been seen so far. One to watch out for as that will pummel the CET figure into the 14s or 15s. I’m not too confident of a 15.5-16.0+ finish now but output could change. It’s nice to see the onset of autumn though. Once mid-September arrives I lose interest in hot weather. We’ll see if this trend continues. 

Very unlikely it will be going below 15C now. It would take something exceptional in the last third of the month- the models aren't showing anything of that magnitude at all.

If this morning's ECM ends up verifying, 16C+ would be pretty likely.

[LetItSnow!]

3 minutes ago, Scorcher said:

Very unlikely it will be going below 15C now. It would take something exceptional in the last third of the month- the models aren't showing anything of that magnitude at all.

If this morning's ECM ends up verifying, 16C+ would be pretty likely.

Not checked model output today but guessing a slightly warmer option is favoured. Yesterday some of the models were showing some genuinely autumnal weather like the GEM.

[Shillitocettwo]

Anything 16.3.C or higher will do nicely thank you, cant believe 15.5.C is the second highest entry!

[The PIT]

Sunny Sheffield down to 17.2C +1.6C above average. Rainfall now up to 9mm 13.7% of the monthly average.

[Roger J Smith]

The 12z GFS has a few cooler days in the mix but overall I would agree it is only going to deflate slowly and a finish in the low to mid 15 area is about as low as I could imagine from this, at the present time we are pretty much above 17 after corrections so to get to 15 will take an average of 12.8 for the second half, the maps look closer to 14 which gets it to about 15.6 maybe. Not overly wet either, one or two significant rainfalls but staying in the 50 mm range with long dry spells shown associated with blocking to the northeast. Shape of the circulation does not favour cold advection and not all that conducive to radiational cooling at night, probably a very foggy stretch of nights and mornings to end the month. 

[damianslaw]

Nothing overly wet on the horizon. A very dry September could be on the cards.. but it only takes a day like yesterday to bring levels suddenly up to or above average.

We've had very little rain for 3 and half weeks. Seem to be experiencing lengthy dry periods punctuated by shorter wet spells..  

[Scorcher]

3 hours ago, LetItSnow! said:

Not checked model output today but guessing a slightly warmer option is favoured. Yesterday some of the models were showing some genuinely autumnal weather like the GEM.

Even if there was a cooler outlook, it's very unlikely to be enough to drop it below 15C now. We're still well over 17C halfway through the month!

[Dancerwithwings]

A long way is a couple of weeks and remember all  (I’m not saying it’ll happen again) but in August after corrections it dropped by 0.5c, in which was a big drop and a surprise to most .....but we’ll see

[The PIT]

Sunny Sheffield down to 17.1C +1.6C above average, Rainfall unchanged.

Slow slide should continue for the next five days

[Summer Sun]

17.4c to the 15th

3.2c above the 61 to 90 average
2.7c above the 81 to 10 average

___________________________

Current high this month 18.1c on the 10th & 11th
Current low this month 14.4c on the 1st

[Scorcher]

1 hour ago, Summer Sun said:

17.4c to the 15th

3.2c above the 61 to 90 average
2.7c above the 81 to 10 average

___________________________

Current high this month 18.1c on the 10th & 11th
Current low this month 14.4c on the 1st

Looks like it's top 5 for warmest first halves. Even with potential corrections it's certainly top 10.

[damianslaw]

1 hour ago, Scorcher said:

Looks like it's top 5 for warmest first halves. Even with potential corrections it's certainly top 10.

If today's models verify the CET should take a rapid fall.. on average latter part of the month does see a significant drop.