September 2020 C.E.T. and EWP forecast contests

[summer blizzard]

Out of interest could Roger or anybody else provide us with the 2016-2019 marks to the 10th and 15th.

[Roger J Smith]

These are the running CET values for 10th and 15th ...

YEAR _______ 10th ____ 15th

2016 ________ 17.0 ____ 17.5

2017 ________ 14.1 ____ 13.6

2018 ________ 14.9 ____ 14.5

2019 ________ 13.5 ____ 14.0

 

[Summer Sun]

14.8c to the 4th

0.2c above the 61 to 90 average
0.4c below the 81 to 10 average

___________________________

Current high this month 15.0c to the 3rd
Current low this month 13.8c to the 1st

[Roger J Smith]

First report on EWP ... has reached 8 mm, looks set to add 30-40 mm over ten days and probably a similar amount after that if GFS is accurate. On its way to another fairly high total by the looks of the guidance. 

[The PIT]

Sunny Sheffield at 14.2C -2.2C below average, Rainfall 6.5mm 9.9% of the monthly average

[Summer Sun]

14.6c to the 5th

0.1c below the 61 to 90 average
0.6c below the 81 to 10 average

___________________________

Current high this month 15.0c to the 3rd
Current low this month 13.8c to the 1st

[Man With Beard]

22 minutes ago, Summer Sun said:

14.6c to the 5th

0.1c below the 61 to 90 average
0.6c below the 81 to 10 average

___________________________

Current high this month 15.0c to the 3rd
Current low this month 13.8c to the 1st

I imagine, given current charts, we'll be close to or just above this figure by mid-month.

To get a 15C plus September really requires 16C by mid-month, so it'll have to be an excellent second half of the month to avoid being in the 14Cs or less.

[Roger J Smith]

Looking quite warm for about ten days then closer to average, overall would expect CET to edge up to around 16 C at times then fall back into the 15s by 22nd (end of GFS run). As you say, most warmish Septembers are falling back after mid-month although there have been two that reached an end point above 15.0 from an equal value on the 15th to their end of month value. Here's the full list of those (not very long) ... by the way, 24 years finished 15.0 or higher, of those 17 were since 1772 and have daily data. Of those, only two had an equal (none higher) value on 30th than on 15th ...

2011 and 2014 (15.1 both 15th and 30th) ... a close similar month was 1998 (15.0 to 14.9).

These others dropped back ... 2006 (17.2 to 16.8), 1865 (18.1 to 16.3), 1949 (17.1 to 16.3), 1795 (17.3 to 16.0), 2016 (17.5 to 16.0), 1780 (17.1 to 15.6), 1999 (16.6 to 15.6), 1895* (15.5 to 15.4), 1929 (16.9 to 15.3), 1779 (15.6 to 15.2), 1898 (17.6 to 15.2), 1961 (15.5 to 15.2), 2005 (17.3 to 15.2), 1825 (15.3 to 15.1), 1958 (16.4 to 15.1), 

and since we're following the template of 2004, I'll add that one (16.1 to 14.9). 

* 1895 did manage to recover to 15.4 from 14.6 on 23rd with a late burst of warmth. 

The warmest September to gain on its mid-month value was 1989 (14.6 to 14.7) followed closely by a more impressive rise in 1985 (13.9 to 14.6). 1970 managed 13.7 to 14.4 and 1956 warmed from 13.7 to 14.3, while 2019 also warmed from 14.0 to 14.3. 

Edited September 6, 2020 by Roger J Smith

[The PIT]

Sunny Sheffield at 14.3C -1.6C below average. Rainfall 6.5mm 9.9% of the monthly average.

[Summer Sun]

14.6c to the 6th

Bang on the 61 to 90 average
0.6c below the 81 to 10 average

___________________________

Current high this month 15.0c to the 3rd
Current low this month 13.8c to the 1st

[Roger J Smith]

(for continuity, 14.5 to 7th was 0.1 below 1961-1990 and 0.6 below 1981-2010 averages)

Edited September 9, 2020 by Roger J Smith

[The PIT]

Sunny Sheffield still at 14.3C -1.5C below normal. Rainfall 8mm 12.2% of the avergae.

With very little rain in the offering it's looking like a very dry 1st half of the month. GFS showing some hot weather on it's way which should cancel out the cold/cool spell in the next few days. Actually probably will more than cancel it out before it may turn cooler again.

[Summer Sun]

15.0c to the 8th

0.5c above on the 61 to 90 average
0.1c below the 81 to 10 average

___________________________

Current high this month 15.0c to the 3rd & 8th
Current low this month 13.8c to the 1st

[cheeky_monkey]

sunny Edmonton is at 12.1c to the 8th..which is +0.7c above average..this is the first time in a long time being able to report tracking a month above average

[The PIT]

Sunny Sheffield up to 15C -0.6C below average. Rainfall unchanged.

[Summer Sun]

15.2c to the 9th

0.7c above the 61 to 90 average
0.1c above the 81 to 10 average

___________________________

Current high this month 15.0c to the 3rd
Current low this month 13.8c to the 1st

[summer blizzard]

Models are a bit erratic depending on orientation but this morning's Euro would see the CET in the 15.7C-16.4C range to the 19th however the high is dragging in cooler uppers afterwards.

Since it's rare to see a marked rise in the second half that would suggest those around 15C probably have the highest chance right now.

We've also hit the highest opening third since 2016.

[The PIT]

Sunny Sheffield down to 14.6C -0.9C below normal. Rainfall unchanged.

[Summer Sun]

14.9c to the 10th

0.4c above the 61 to 90 average
0.1c below the 81 to 10 average

___________________________

Current high this month 15.2c to the 9th
Current low this month 13.8c to the 1st

[Scorcher]

23 hours ago, summer blizzard said:

Since it's rare to see a marked rise in the second half that would suggest those around 15C probably have the highest chance right now.

Rare but possible- just because it's a cooling month on average doesn't guarantee it will get cooler as the month progresses. There are examples of warm second halves of September- 2011 is one and I'm sure there are plenty of others in the records.

[damianslaw]

2 hours ago, Scorcher said:

Rare but possible- just because it's a cooling month on average doesn't guarantee it will get cooler as the month progresses. There are examples of warm second halves of September- 2011 is one and I'm sure there are plenty of others in the records.

Much depends on orientation of heights, we  start to begin to see significant cooling at night which can cancel out high maxima. 

[Scorcher]

15 minutes ago, damianslaw said:

Much depends on orientation of heights, we  start to begin to see significant cooling at night which can cancel out high maxima. 

Indeed- you can still get warm nights late in the month though with the right setup. It's worth remembering that the SSTs are still very high in late September. I recall in 2011 that the nights were very warm indeed at the end of the month. I will never forget seeing people sitting outside the pubs in shorts at midnight on October 1st- there wasn't a hint of a chill in the air.

Edited September 11, 2020 by Scorcher

[Man With Beard]

Any chance of a 20C CET day next week?

[Summer Sun]

14.8c to the 11th

0.4c above the 61 to 90 average
0.2c below the 81 to 10 average

___________________________

Current high this month 15.2c to the 9th
Current low this month 13.8c to the 1st

[Roger J Smith]

EWP update ... 12 mm to 10th, not much added on 11th, 20-25 mm average is the GFS 10-day prediction ... that gives a total of about 33-38 mm. The final six days of the GFS run look fairly unsettled and could add 20 mm. So we would be in the 50-60 mm range nearing the end of the month. 

As to CET, would agree there is some potential for 19-20 C days next week, even after that it only cools off to around 16-17. The running CET seems likely to keep climbing for about a week to around 16.5 then would probably edge down to the high 15s. Guesses in the range 14.8-16.2 are probably favoured at this point.