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

[feb1991blizzard]

On 22/09/2021 at 21:59, Roger J Smith said:

The current EWP end point is around 50 mm (currently 24 mm). This has to be qualified with considerable uncertainty as there's now a rather powerful low expected to form near the Irish Sea on the 28th-29th bringing considerably more rainfall to Ireland, so any changes in details could increase that outcome.

These developments will probably mute any colder turn next week and keep the average in the low 16s before corrections, so 15.8 to 16.2 looks to be the most likely finishing range for CET now. 

I won't post any EWP scores until we see what actually happens, but on 50.1 mm the scoring I see in my file changes the annual leader from snowray to feb91blizzard, probably any outcome below 65 mm would have that effect, and Reef would move up fairly close to second (that would drop back a bit for every mm above 50 as Reef said 49). 

Its looking like i could now bust on the low side when i wouldnt have thought possible a week ago - could end up 75mm now, a right deluge the next few days.

[Scorcher]

Still 16.9C today- this spell coming up probably scuppers any chance of challenging 2006 though.

[The PIT]

Sunny Sheffield at 16.8C +2.4C above normal. Rainfall 9.6mm 14.6% of the monthly average.

Latest projection for sunny Sheffield is 16.2C to 16.4C. 16.4C is needed for a new record. Rainfall wise it's like September is out of the top ten driest now.

Edited September 27, 2021 by The PIT

[Roger J Smith]

EWP now around 42 mm (36 mm to Sunday 26th, map estimate for 27th is 6 mm as the north was wet most other areas not that much) ... later today and rest of month about 15-20 mm could be added (grid average, obviously some places in Wales and Cumbria will get far more). Now thinking the landing zone has shifted to around 60 mm. Oh well ... the CET will probably finish on 16.3-16.4 before corrections and 16.1-16.2 after? We'll see. 

[The PIT]

Sunny Sheffield at 16.8C +2.5C above normal. Rainfall 22.7mm 34.5% of the monthly average.

Now looking that we will end up at around 16.2C to 16.3C so unlikely any new records.

Edited September 28, 2021 by The PIT

[Roger J Smith]

CET of 13.7 on Monday is still 0.3 above the record high minimum value of 13.4 (1949). Overall has dropped to 16.75 (they are calling that 16.8). Further drops of about 0.15 a day for three days would leave it at 16.3 before adjustments. (will post the usual daily CET update around midnight if Summer Sun doesn't do it later, that 16.8 is 3.0 above normal 81-10).

Edited September 28, 2021 by Roger J Smith

[Roger J Smith]

Just to maintain the continuity ... I was going to post this late yesterday and forgot (but it is late yesterday here so ...)

16.8c to the 27th

3.0c above the 61 to 90 average
2.6c above the 81 to 10 average

(2.5 above the 91 to 20 average)

(0.2 below the 2006 record value of running CET to 27th _ subject to adjustment could be 0.4 or 0.5 below it actually)

___________________________

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

____________________________

There should be an update fairly soon through the 28th. My guess is 16.6 because that 16.8 you see is rounded up from 16.75. 

[Roger J Smith]

On 27/09/2021 at 02:22, feb1991blizzard said:

Its looking like i could now bust on the low side when i wouldnt have thought possible a week ago - could end up 75mm now, a right deluge the next few days.

I think you might be okay, the EWP was 40 mm to 27th, then yesterday's grid average looks to be 15-20 mm so 55-60 mm, time running out with the next system probably mostly north of the border. You said 65 mm so could be quite close with that. I will wait for 2nd Oct when the map tracker is complete and estimate some scores, but I think the final value on 5th could move a bit from whatever that estimate turns out to be. If this had been a February then I would be doing a lot better. 

[Bobd29]

24 minutes ago, Roger J Smith said:

I think you might be okay, the EWP was 40 mm to 27th, then yesterday's grid average looks to be 15-20 mm so 55-60 mm, time running out with the next system probably mostly north of the border. You said 65 mm so could be quite close with that. I will wait for 2nd Oct when the map tracker is complete and estimate some scores, but I think the final value on 5th could move a bit from whatever that estimate turns out to be. If this had been a February then I would be doing a lot better. 

Try to keep it as close to 60mm Roger, lol.

[Summer Sun]

16.6c to the 28th

2.9c above the 61 to 90 average
2.5c 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

[The PIT]

Sunny Sheffield down to 16.6C +2.4C above normal. Rainfall 32.3mm 48.9% of the monthly average

[Shillitocettwo]

16.58.C and 27 hours to go......am I right in thinking 16.26.C or more is required to win this? 

 

   However it doesn't exactly look warm tomorrow and I think downward correction would knock me off anyway.... shame Autumn turned up in the last 4 days of September otherwise 2006 may have lost its crown! 

[feb1991blizzard]

13 hours ago, Roger J Smith said:

I think you might be okay, the EWP was 40 mm to 27th, then yesterday's grid average looks to be 15-20 mm so 55-60 mm, time running out with the next system probably mostly north of the border. You said 65 mm so could be quite close with that. I will wait for 2nd Oct when the map tracker is complete and estimate some scores, but I think the final value on 5th could move a bit from whatever that estimate turns out to be. If this had been a February then I would be doing a lot better. 

Cheers - yes i over estimated that deluge the other day i think, either way i am not going to be far off i suppose.

[Frigid]

Is there a chance the CET will drop below 16c now? 

[Summer Sun]

16.4c to the 29th

2.8c above the 61 to 90 average
2.3c 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

[The PIT]

Sunny Sheffield at 16.2C +2.1C above normal. Rainfall unchanged.

[Roger J Smith]

10 hours ago, Frigid said:

Is there a chance the CET will drop below 16c now? 

After today which has been a bit milder, the provisional will likely finish 16.3 but could drop just below 16.25 and finish 16.2, but after they finish adjustments, who knows, hoping they go to 16.1 which will be a new value and will keep shillitocettwo from falling behind all the people at 15.0 in the contest, otherwise it means nothing to anyone in the contest as 15.5 is the second highest forecast so I doubt that it will go lower than 15.8. Currently 16.0 is tied fifth warmest (1795, 2016) and 16.3 tied third warmest (1865, 1949) while seventh is down at 15.7 (1760), so any of 15.8, 15.9, 16.1 or 16.2 would be new ground for September CET. I have little luck with forecasts of adjustments but the average over many years is 0.2 so 16.1 is the most likely call. 

Now, an update on the EWP. The heavy rain on Tuesday is now in the tracker which shows 56 mm to the 28th. The meteociel 24h map for 29th shows a grid average of perhaps 2-3 mm (but runs 06z to 06z so I would add in a bit for 00z-06z, we must be close to 60 mm right now plus anything falling today. A look at the time lapse radar suggests that this might be 2-3 mm. A finish in the low 60s seems likely then. 

Edited September 30, 2021 by Roger J Smith

[damianslaw]

A very warm September then, akin to 2006 which followed on from a rather cloudy lacklustre August.. mind it came on the back of a very warm June and hot July.

September 2021 will be remembered for its dryness rather than warmth. Only the last few days brought any measurable rainfall.. but what we've had certainly made up for the drought. 

[Roger J Smith]

October and November CET values following top 24 September CET

__ (and where the seasons finished in rank) __

 

YEAR ___ Sep CET ______ Oct CET _ Nov CET ___ autumn __ rank

2006 ___ (1) 16.8 _______ 13.0 ______ 8.1 ______ 12.63 ____ (1)

1729 ___ (2) 16.6 _______ 10.1 ______ 8.1 ______ 11.60 ____ (t6)

1865 __ (t3) 16.3 ________ 9.7 ______ 6.7 ______ 10.90 ____ (t33)

1949 __ (t3) 16.3 _______ 11.7 ______ 6.6 ______ 11.53 ____ (t8)

1795 __ (t5) 16.0 _______ 11.7 ______ 4.5 ______ 10.73 ____ (t44)

2016 __ (t5) 16.0 _______ 10.9 ______ 5.6 ______ 10.83 ____ (38)

1760 ___ (7) 15.7 ________ 9.2 ______ 5.7 ______ 10.20 ____ (t102)

1780 __ (t8) 15.6 ________ 9.1 ______ 4.4 _______ 9.70 ____ (t178)

1999 __ (t8) 15.6 _______ 10.7 ______ 7.9 ______ 11.40 ____ (t14)

1895 __ (10) 15.4 ________ 7.1 ______ 7.5 ______ 10.00 ____ (t129)

1730 __(t11) 15.3 _______ 10.9 ______ 9.2 ______ 11.80 ____ (t4)

1731 __(t11) 15.3 _______ 12.3 ______ 7.8 ______ 11.80 ____ (t4)

1929 __(t11) 15.3 ________ 9.6 ______ 6.7 ______ 10.53 ____ (t71)

1750 __(t14) 15.2 ________ 9.2 ______ 4.0 _______ 9.47 ____ (t223)*

1779 __(t14) 15.2 _______ 10.9 ______ 5.7 ______ 10.60 ____ (t62)

1898 __(t14) 15.2 _______ 11.3 ______ 7.2 ______ 11.23 ____ (t17)

1961 __(t14) 15.2 _______ 10.9 ______ 6.0 ______ 10.70 ____ (t46)

2005 __(t14) 15.2 _______ 13.1 ______ 6.2 ______ 11.50 ____ (t11)

1825 __(t19) 15.1 _______ 10.8 ______ 5.2 ______ 10.37 ____ (t87)

1958 __(t19) 15.1 _______ 10.8 ______ 6.4 ______ 10.77 ____ (t41)

2011 __(t19) 15.1 _______ 12.6 ______ 9.6 ______ 12.43 ____ (2)

2014 __(t19) 15.1 _______ 12.5 ______ 8.6 ______ 12.07 ____ (3)

1678 __(t23) 15.0 ________ 8.5 ______ 6.0 _______ 9.83 ____ (t154)

1708 __(t23) 15.0 ________ 8.5 ______ 7.0 ______ 10.17 ____ (t105)

averages __ 15.5 ________ 10.6 ______ 6.7 ______ 11.0 _____ (55)

(note that 11.0 ranks 25th but the average of ranks is higher, a distortion created by the skewed distribution.)

... this analysis shows that the September warmth is statistically more or less nearly extinct within 30 days but a

minor resurgence takes place in Nov which has averaged further above the 1759-2020 mean than October has done. 

_______________________________________________________________

Of the top seven autumn CETs all were associated with a top 22 September, except 1818

which started from a more average 13.3 Sep and added 12.0, 9.5 Oct-Nov to finish at 11.60 (t6). 

Two autumns tied 1949 in the list above at t8, 1959 and 1978, 1959 had a t24th 14.9 Sep and

1978 was 14.2 (t76 warmest).

* 1750 was the only season to end up colder than the median value, and was t135 coldest.

The warmest October (2001) anchored a season that ended t14 warmest (11.40) and the

warmest November (1994) anchored a season that ended t25 warmest (11.00). 

Note that 14 of these 24 warmest Septembers occurred before 1900, and 18 out of 24 before 1999 (1961 the last of those) when the first of the six more recent examples shows up. Long absences were noted such as 1826 to 1864 (no entries) and 1962 to 1998 (no entries). The warmest September in that latter interval was 14.9 in 1998 and before that 14.7 on three occasions (1980, 89, 91). 

 

Edited September 30, 2021 by Roger J Smith

[Summer8906]

11 hours ago, Roger J Smith said:

Note that 14 of these 24 warmest Septembers occurred before 1900, and 18 out of 24 before 1999 (1961 the last of those) when the first of the six more recent examples shows up. Long absences were noted such as 1826 to 1864 (no entries) and 1962 to 1998 (no entries). The warmest September in that latter interval was 14.9 in 1998 and before that 14.7 on three occasions (1980, 89, 91). 

 

 

Surprised 1998 was warmer than any other year since 1962; I recall a one-week warm sunny spell but aside from that it seemed to be wet with unremarkable temperatures. I'd have expected several others (1979, 1982, 1985, 1989, 1990, 1991, 1996 and 1997) to have been warmer as I remember most of those to have many warm sunny days. September 1997 in particular seemed very notably warm and sunny. Perhaps some of them had cool nights which brought the CET down.

Edited October 1, 2021 by Summer8906

[Methuselah]

7 minutes ago, Summer8906 said:

Surprised 1998 was warmer than any other year since 1962; I recall a one-week warm sunny spell but aside from that it seemed to be wet with unremarkable temperatures. I'd have expected several others (1979, 1982, 1985, 1989, 1990, 1991, 1996 and 1997) to have been warmer as I remember most of those to have many warm sunny days. September 1997 in particular seemed very notably warm and sunny. Perhaps some of them had cool nights which brought the CET down.

And maybe 1998 had lots of warm, muggy nights?

[Summer8906]

7 minutes ago, Ed Stone said:

And maybe 1998 had lots of warm, muggy nights?

Possibly yes. I think the unsettled spells were southwesterly rather than northwesterly in the main, which could have resulted in flatlining temps (e.g. 19C max 15C min).

That's the only issue with CET - unless nights are really notably different from average, you tend not to notice them. Septembers ranked by mean max are more likely to accord with memories of what was a 'good' September - I'd expect years like 1997 to come out near the top on such a measure.

Edited October 1, 2021 by Summer8906

[mulzy]

Looks like final CET for September came in at 15.9C.

[North-Easterly Blast]

The final September CET comes in at 15.92*C, which was the seventh warmest September since records began in 1659, and just behind 2016.  A notably warm September we have just had, which actually makes it that four of the ten warmest Septembers in the 363 year CET record have occurred in the last 22 years, which is a remarkable statistic.

[Walsall Wood Snow]

September 2021 is the first September in the CET record (dating back to 1659) with a mean temp of 15.9c.