September 2022 C.E.T. and EWP forecast contests

[damianslaw]

A marked cool down forecast by most models, as we lose the cloudy skies and also pull in cooler air from the north through the coming week, this combination will result in much chillier minima, with maxima only around average at best - the sun is weakening now. 

[The PIT]

Sunny Sheffield down to 17.9C +1.9C above normal. Rainfall 37.4mm 56.8% of the monthly average.

[Summer Sun]

17.6c to the 10th

4.0c above the 61 to 90 average
2.6c above the 81 to 10 average

[Earthshine]

17 hours ago, damianslaw said:

A marked cool down forecast by most models, as we lose the cloudy skies and also pull in cooler air from the north through the coming week, this combination will result in much chillier minima, with maxima only around average at best - the sun is weakening now. 

Personally happy with that!  After a fantastic warm summer I think some of those lovely cooler, sunny September days will do nicely!

[damianslaw]

2 hours ago, Earthshine said:

Personally happy with that!  After a fantastic warm summer I think some of those lovely cooler, sunny September days will do nicely!

BBC going for 5 degrees minima by end of the week, whilst nothing too unusual for mid September, it's a clear signal we are waving good bye to summer properly.. yes we can have maxima well into the 20s in October still, but the lowering sun and less daylight combined with decaying state of nature, tells you it clearly is no longer summer, however long we may want to cling on, the same thing happens opposite end of the year, cold and snow can easily occur in April, but it is clearly Spring. The time of full change is the equinox.

Edited September 11, 2022 by damianslaw

[Roger J Smith]

17.4, 17.2, 17.0, 16.7, 16.4, 16.0, 15.6, 15.2, 15.1, 15.0, 14.9, 14.8, 14.9, 15.1, 15.3, 15.2, 15.1

The above are my estimates for running CET 11th-27th following a rather cool spell expected from 13th to 19th, then a warm spell after the 21st, The steady fall would likely be halted for about a week if things work out that way. It could fall a bit faster if the nights are cold enough. However it could also rebound up a bit more than I show if the warm spell maxes out. Record highs remain in the 19 to 21 range for the rest of the month and even into the first week of October, and a 20 C day late in the month would raise the running CET by 0.3 or 0.4 at that point. 

[Don]

3 hours ago, Roger J Smith said:

17.4, 17.2, 17.0, 16.7, 16.4, 16.0, 15.6, 15.2, 15.1, 15.0, 14.9, 14.8, 14.9, 15.1, 15.3, 15.2, 15.1

The above are my estimates for running CET 11th-27th following a rather cool spell expected from 13th to 19th, then a warm spell after the 21st, The steady fall would likely be halted for about a week if things work out that way. It could fall a bit faster if the nights are cold enough. However it could also rebound up a bit more than I show if the warm spell maxes out. Record highs remain in the 19 to 21 range for the rest of the month and even into the first week of October, and a 20 C day late in the month would raise the running CET by 0.3 or 0.4 at that point. 

Looking likely to be a 15C plus month currently, but still time for that to change.  Looking rather touch and go I think!!

[Summer Sun]

17.5c to the 11th

3.9c above the 61 to 90 average
2.5c above the 81 to 10 average

Edited September 12, 2022 by Summer Sun

[damianslaw]

Quite a cool down forecast from mid week on and into next week. Even London looks like it will return means 13-14 degree range, below par for mid Sept, CET zone a degree or so cooler would expect. The first half of Sept 2022 will though go down as one of warmest on record I expect. The slow moving low pressure system to the SW key reason, it maintained very warm tropical air over UK and prevented clear skies which at this time of year begin to have a marked cooling effect on mean values. 

[The PIT]

Sunny Sheffield down to 17.6C +1.7C above normal. Rainfall 38.9mm 59.1% of the monthly average.

[Summer Sun]

17.5c to the 12th

4.0c above the 61 to 90 average
2.5c above the 81 to 10 average

[The PIT]

Sunny Sheffield still at 17.6C +1.8C above normal. rainfall up to 41.1 62.5% of the monthly average.

[Roger J Smith]

EWP had reached 51.3 mm by 11th and has added about 5 mm by 12z today, but apart from the rain now falling in the south, very little more is indicated with some places showing zero rainfall to 29th on the GFS estimates. The end of month estimate at the moment then is around 60-65 mm. 

The CET looks similar to my previous estimate and seems likely to drop steadily for about a week now, then hold at whatever value it reaches or perhaps rally slightly, but then fall back with another cooler turn towards the end, with the value around 15 C by end of the month or possibly lower. 

[The PIT]

Yup now looks like a split month coming up rainfall wise a wet first half and drier 2nd half.  So looking like we will get stuck on 62% of average rainfall.

[Don]

48 minutes ago, Roger J Smith said:

EWP had reached 51.3 mm by 11th and has added about 5 mm by 12z today, but apart from the rain now falling in the south, very little more is indicated with some places showing zero rainfall to 29th on the GFS estimates. The end of month estimate at the moment then is around 60-65 mm. 

The CET looks similar to my previous estimate and seems likely to drop steadily for about a week now, then hold at whatever value it reaches or perhaps rally slightly, but then fall back with another cooler turn towards the end, with the value around 15 C by end of the month or possibly lower. 

Still touch and go whether we will get below that 15C for the final figure!

Edited September 13, 2022 by Don

[damianslaw]

2 hours ago, The PIT said:

Yup now looks like a split month coming up rainfall wise a wet first half and drier 2nd half.  So looking like we will get stuck on 62% of average rainfall.

Could be quite an odd September, mild wet first half, cool dry second half, normally first half associated with dry, and second half wet, with cool only at the end. It's turning into a very different September.

[Roger J Smith]

The last time the second half of September was quite dry was 2009, it was rather dry also in 2011 and from 2013 to 2016, and notably wet most of the past four years, as well as in 2012. The first half of September 2009 was not as wet as this year (EWP). Of course the summers had wide disparities. There was less than 2 mm of rain from 16th to 30th in 2009. The first two days had almost 20 mm and after that it didn't rain all that much from 3rd to 15th either (about 10 mm).  A more normal rainfall pattern returned on 4th October and eventually the autumn became very wet with severe flooding in parts of northern England and Ireland in mid-November. 

[Summer Sun]

17.3c to the 13th

3.7c above the 61 to 90 average
2.4c above the 81 to 10 average

[Don]

1 hour ago, Summer Sun said:

17.3c to the 13th

3.7c above the 61 to 90 average
2.4c above the 81 to 10 average

Should see quite a drop between now and early next week.

[The PIT]

Sunny Sheffield at 17.3C +1.6C above normal. Rainfall unchanged.

GFS today throws up a hot end to September may get a few new daily records. lalala land so may disappear. A steady drop for the next five days with a slow down next week. Still looks to be an above average month even more so if the hot spell comes off.

[Summer Sun]

17.1c to the 14th

3.5c above the 61 to 90 average
2.3c above the 81 to 10 average

[The PIT]

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

[damianslaw]

Down it goes and significantly so over next few days.

[Summer Sun]

16.8c to the 15th

3.3c above the 61 to 90 average
2.1c above the 81 to 10 average

[The PIT]

Sunny Sheffield down to 16.8C +1.3C above average. rainfall unchanged.