October 2016 C.E.T. forecasts

[Summer Sun]

11.3 to the 4th

0.9 below the 61 to 90 average

1.0 below the 81 to 10 average

[BLAST FROM THE PAST]

I'm generally happy with he synoptic pattern but that lovely Scandi High a tad further N than anticipated and not getting the warmer air dragged in either and these cool nights will kill my guess off if it keeps up like that

 

BFTP

[Methuselah]

Mine too, Fred!

[NorthYorksWeather]

After 4 days the October mean is 10.7c here, 0.9c above the 1981-2010 average.

[damianslaw]

If the models verify as shown, fully expect to be below average the running Oct CET mean come mid month, and possibly quite a bit below. However, we've had many months that have flipped at the half way stage resulting in a near average/average return.

If we end up below 10 degrees, I wonder when was the last time we saw a 6 degree + difference in CET values from month to the next. Nov/Dec 2010 could be one example, March 2013/April 2013 possibly another.. can't be that many examples.

However, the most likely 2 months to achieve this feat I would have thought are Sept and October, as on average we see the largest difference / drop in CET finishing values between Sept and October, Oct and Nov a close second followed by March and April..

[Roger J Smith]

If you're wondering how often second half of OCT is warmer than first half, then

from 1772 to 2015 (244 years) there were 36 cases where 16th-31st was warmer than 1st-15th. That is about 15% of the total. Of those, 14 (about 6%) managed to warm up by 1.0 deg or more.

 

TOP 14 WARMINGS 1-15 to 16-31 OCT (includes all cases > 1.0 deg)

 

YEAR ____ FIRST 15 DAYS __ 16th-31st ___ INCREASE

1849 ______ 7.65 __________ 10.66 _______ 3.01

1888 ______ 6.43 ___________ 9.28 _______ 2.85

1867 ______ 8.01 __________ 10.48 _______ 2.47

1803 _______8.22 __________10.33 _______ 2.11

2014 _____ 11.69 __________ 13.22 _______ 1.53

1871 ______ 9.07 __________ 10.51 _______ 1.44

1809 _______9.47 __________10.88 _______ 1.41

1838 ______ 9.11 __________ 10.44 _______ 1.33

1897 ______ 9.21 __________ 10.53 _______ 1.32

1860 ______ 9.43 __________ 10.69 _______ 1.26

1884 ______ 8.82 ___________ 9.91 _______ 1.09

1952 ______ 8.25 ___________ 9.31 _______ 1.06

1977 _____ 11.23 __________ 12.24 _______ 1.01

1925 ______ 9.90 __________ 10.88 _______ 0.98

 

 

Edited October 6, 2016 by Roger J Smith

[Lettucing Gutted]

I'm very surprised Octobers 2009 and 2015 aren't in that list Roger.  They had very mild second halves if I remember correctly.

Edited October 7, 2016 by Lettucing Gutted

[Summer Sun]

11.9 to the 5th

0.3 below the 61 to 90 average

0.3 below the 81 to 10 average

[Man With Beard]

5 hours ago, Summer Sun said:

11.9 to the 5th

0.3 below the 61 to 90 average

0.3 below the 81 to 10 average

And that's as high as it will go. Only decent cloud amounts at night will prevent a mighty drop in the next ten days.

[The PIT]

Sunny Sheffield at 10.6C 0.4C above normal. Won't change much for sometime looking at GFS.

[Roger J Smith]

19 hours ago, Lettucing Gutted said:

I'm very surprised Octobers 2009 and 2015 aren't in that list Roger.  Thy had very mild second if I remember correctly.

2009 rose by 0.35 deg, the table only lists the cases that managed a 1.0 (rounded off) increase or more.

2015 would surprise you, yes it was mild at the end of the month but the second half was 0.2 colder than the first fifteen days.

The only near-miss from the table in recent times was 1988 which rose by 0.88 deg from 9.98 to 10.86. That would be 15th on the list, these years also broke 0.5 increases: 1833 (0.83), 1923 (0.80), 1927 (0.77), 1936 (0.72), 1904 (0.71), 1853 (0.67), 1898 (0.66).

The frequency of this October late increase (the long-term average is a drop of 2.01 deg) has been on the decline recently. From 1904 to present, I found 14 of the 36 cases  That is in itself lower than the pace from 1772 to 1903 but in the second half of the recent period (1960 to 2015) only six of those 14, The period 1860 to 1899 managed 11 in 40 years, about double the average.

[Lettucing Gutted]

On ‎05‎/‎10‎/‎2016 at 21:42, damianslaw said:

However, the most likely 2 months to achieve this feat I would have thought are Sept and October, as on average we see the largest difference / drop in CET finishing values between Sept and October, Oct and Nov a close second followed by March and April..

It will be even more remarkable for a very mild September to be followed by any sort of cold October as this very rarely happens.  So far in the CET record there is a disproportionate case of the biggest September to October drops caused by near average/slightly mild Septembers followed by very cold Octobers, the most extreme case of this occurring in 1740.

Edited October 7, 2016 by Lettucing Gutted

[Summer Sun]

11.7 to the 6th

0.5 below the 61 to 90 average

0.4 below the 81 to 10 average

[The PIT]

Sunny Sheffield up to 10.8C due a mild night. Another rise for today likely depending on how far the temperatures drop tonight.

[damianslaw]

10 hours ago, Lettucing Gutted said:

It will be even more remarkable for a very mild September to be followed by any sort of cold October as this very rarely happens.  So far in the CET record there is a disproportionate case of the biggest September to October drops caused by near average/slightly mild Septembers followed by very cold Octobers, the most extreme case of this occurring in 1740.

Hi - do you have the stats? 1740 ominous indeed...

[Mapantz]

Currently at 12°C here, 1.2°C above the MetO 81 - 10 regional average.

Likely to drop to drop on my next update.

[Weather-history]

September and October 1895, September had that remarkable heatwave during the last week and October 1895 had the low level snowfalls and sharp frosts at the back end.

 

[Roger J Smith]

OCTOBER CET after TOP 30 (pre-2016) SEPTEMBER CET (and bonus NOV, WINTER)

includes all Septembers 14.9 or warmer

___________________________________________________________________________

 

Year ____ SEP ___ OCT __ NOV ___ Winter (DJF avg) __ notes on 2.0 or lower months

2006 ____ 16.8 ___ 13.0 ___ 8.1 ____ 6.4 (Dec, Jan very mild)

1729 ____ 16.6 ___ 10.1 ___ 8.1 ____ 4.6

1865 ____ 16.3 ____ 9.7 ___ 6.7 ____ 5.3

1949 ____ 16.3 ___ 11.7 ___ 6.6 ____ 5.1 (late Jan cold)

1795 ____ 16.0 ___ 11.7 ___ 4.5 ____ 6.2 (Dec, Jan very mild)

1760 ____ 15.7 ____ 9.2 ___ 5.7 ____ 5.8

1780 ____ 15.6 ____ 9.1 ___ 4.4 ____ 3.4

1999 ____ 15.6 ___ 10.7 ___ 7.9 ____ 5.4

1895 ____ 15.4 ____ 7.1 ___ 7.5 ____ 4.4

1730 ____ 15.3 ___ 10.9 ___ 9.2 ____ 2.5 (1.9 Jan)

1731 ____ 15.3 ___ 12.3 ___ 7.8 ____ 4.7

1929 ____ 15.3 ____ 9.6 ___ 6.7 ____ 4.6

1750 ____ 15.2 ____ 9.2 ___ 4.0 ____ 3.2 (Feb 1.5)

1779 ____ 15.2 ___ 10.9 ___ 5.7 ____ 1.4 (Jan --0.9)

1898 ____ 15.2 ___ 11.3 ___ 7.2 ____ 5.8 

1961 ____ 15.2 ___ 10.9 ___ 6.0 ____ 3.6 (Dec 2.2)

2005 ____ 15.2 ___ 13.1 ___ 6.2 ____ 4.1

1825 ____ 15.1 ___ 10.8 ___ 5.2 ____ 3.8 (Jan 0.4)

1958 ____ 15.1 ___ 10.1 ___ 6.4 ____ 3.6 (Jan 1.6)

2011 ____ 15.1 ___ 12.6 ___ 9.6 ____ 5.1 

2014 ____ 15.1 ___ 12.5 ___ 8.6 ____ 4.5

1678 ____ 15.0 ____ 8.5 ___ 6.0 ____ 1.0 (all three cold, 0.5, 1.0, 1.5)

1708 ____ 15.0 ____ 8.5 ___ 7.0 ____ 1.2 (very cold Jan 1709 --1.5, Feb 2.0)

1821 ____ 14.9 ___ 10.4 ___ 8.6 ____ 5.8

1875 ____ 14.9 ____ 8.9 ___ 5.4 ____ 4.1

1933 ____ 14.9 ___ 10.1 ___ 5.6 ____ 3.2 (Dec 1.6)

1947 ____ 14.9 ___ 10.6 ___ 7.2 ____ 5.1

1959 ____ 14.9 ___ 12.6 ___ 7.1 ____ 4.6

1998 ____ 14.9 ___ 10.6 ___ 6.2 ____ 5.4

2004 ____ 14.9 ___ 10.5 ___ 7.7 ____ 5.2

__________________________________________________________

ANALYSIS

Most Octobers were near normal but there were a few top twenty cases. Many Novembers were rather mild and a few were very mild; the coldest of all of them was only 4.0 (1750). Winters started to show considerable variation and there were eleven months out of ninety that fell below 2.0. Three or four winters could be classed as very mild. 

On the whole there are no strong trends following a warm September but a slight return of this tendency in November can be seen. 

Edited October 7, 2016 by Roger J Smith

[damianslaw]

Thanks for these stats, gosh look at 1895 a 8.3 CET drop between September and October, must be one of the largest differences between 2 adjoining months. It is way ahead of others, quite a few 6-6.5 degree range, which we may see this year if the current synoptics play out.

[Roger J Smith]

It was the third largest drop from one month to another.

Not surprisingly the seven largest drops occur in either Sep to Oct or Oct to Nov. and this increases to nine out of ten of the ten largest drops, Nov to Dec enters at that point.

1. September 1740 (14.0) to October 1740 (5.3) managed 8.7.

2. October 1807 (11.4) to November 1807 (2.9) was 8.5

3. September 1895 (15,4) to October 1895 (7.1) was 8.3.

4. October 1921 (12.8) to November 1921 (4.6) fell 8.2

5. October 1684 (11.0) to November 1684 (3.0) was 8.0

6. October 1851 (10.8) to November 1851 (3.1) was 7.7

7. October 1861 (11.8) to November 1861 (4.2) was 7.6

t8 October 1679 (11.0) to November 1679 (3.5) was 7.5

t8 September 1880 (14.5) to October 1880 (7.0) was 7.5

t8 November 1981 (7.8) to December 1981 (0.3) was 7.5

 

 

The largest drops in all twelve pairs of consecutive months are

Jan to Feb 5.0 (1983) 6.7 to 1.7

Feb to Mar 4.0 (1883) 5.9 to 1.9

Mar to Apr 1.6 (1780) 7.9 to 6.3

Apr to May 0.6 (1755) 10.0 to 9.4

May to Jun 0.5 (1833) 15.1 to 14.6

June to July 2.0 (1858) 16.8 to 14.8 and 1676 (16 to 14)

July to Aug 3.6 (2006) 19.7 to 16.1

Aug to Sep 6.4 (1807)  16,9 to 10.5

Sep to Oct 8.7 (1740) 14.0 to 5.3

Oct to Nov 8.5 (1807) 11.4 to 2.9

Nov to Dec 7.5 (1981) 7.8 to 0.3

Dec to Jan 7.1 (1828-29) 7.4 to 0.3

Edited October 9, 2016 by Roger J Smith

[Summer Sun]

11.8 to the 7th

0.4 below the 61 to 90 average

0.3 below the 81 to 10 average

[BornFromTheVoid]

Minimum today of 9.9C, while maxima look like hitting the high 15s, so an increase to 11.9C is likely on tomorrows update.

After that the 06z GFS has the CET at:

11.7C to the 9th (10.3: -1.6)
11.4C to the 10th (8.8: -3.4)
11.3C to the 11th (10.5: -1.2)
11.3C to the 12th (10.7: -0.9)
11.2C to the 13th (10.6: -0.8)
11.3C to the 14th (11.9: +1.0)
11.4C to the 15th (12.4: +1.6)
11.6C to the 16th (15.6: +5.3) [Record High: 15.8C]
11.9C to the 17th (15.8: +5.8) [Record High: 15.6C]

Remaining relatively cool in the near term, with temps about 0.5C below the 81-10 average as we near mid month. The GFS then goes for some record breaking warmth as we start the second half, but that's much too far off to take seriously at this stage.

 

[The PIT]

Sunny Sheffield still at 10.8C due to colder night than expected. All depends on what the skies do clear temps will fall away cloudy stay up. The interest thing is how uniform the temperatures are with very little variation.  The question is how long will this block last they are hints of it migrating westward whether this will allow colder air to come down from the north or even mild air over the top remains to be seen or even if it does migrate or not.

[NorthYorksWeather]

10.9c to the 8th here, 1.1c above 1981-2010 average, expecting a drop to around average by mid month. 

[Summer Sun]

11.9 to the 8th

0.2 below the 61 to 90 average

0.1 below the 81 to 10 average