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

[Dancerwithwings]

October can change very quickly....a little extreme but on the 25th 2008 we had uppers of 12c across southern parts of the UK and just 3 to 4 days later we had day time snow and night time temps of -4 and back then the models 7 days prior had no sign of any kind of northerly incoming.

[The PIT]

Sunny Sheffield down to 10.3C -2.1C below normal. Rainfall 68.5mm 82.7% of the monthly average.

[Weather-history]

10 hours ago, summer blizzard said:

October usually sees a larger collapse than even September, it would be interesting to see which October's actually had a warmer second half.

October 1888 was a strange one, that started off unusually cold and there was an unusually mild spell during the last week. Overall it was a cold month

 

[The PIT]

22 hours ago, mb018538 said:

Funny how quickly things can change in a few days.....from next Monday onwards we're now looking at very mild weather taking over for 5-7 days at least. The colder than normal October may not happen after all!

No sign of very mild weather on the way. Temperatures look stay fairly similar to what they are now however they should be high enough to allow the plateauing of the CET so the month may end up close to average if it came off that way.

[mb018538]

1 hour ago, The PIT said:

No sign of very mild weather on the way. Temperatures look stay fairly similar to what they are now however they should be high enough to allow the plateauing of the CET so the month may end up close to average if it came off that way.

There was a day or two ago - go and check the output! Very volatile at the moment though - if the low to the SW isn't quite in the right place then we could well just see average to cool unsettled weather instead of a milder blast. ECM this morning still has 17c for Tuesday - not quite the 20/21c that was shown a couple of days ago, but mild-ish for late October.

[Summer Sun]

10.9c to the 12th

0.7c below the 61 to 90 average
1.0c below the 81 to 10 average

___________________________

Current high this month 11.7c to the 7th
Current low this month 10.7c to the 1st

[summer blizzard]

Looking strongly like the coolest first half to October since 2012 according to Roger's earlier stats and recent model trends to day 10 would leave any real upward pressure quite late. 

[mb018538]

On 14/10/2020 at 11:21, Summer Sun said:

10.9c to the 12th

0.7c below the 61 to 90 average
1.0c below the 81 to 10 average

___________________________

Current high this month 11.7c to the 7th
Current low this month 10.7c to the 1st

Unchanged for the last 2 days - CET standing at 10.9c to the 14th

[cheeky_monkey]

cloudy Edmonton is at 6.8c which is +1.7c above normal..after a warm start to the month winter has arrived so watch the average tank over the next week as we start running into a fair few ice days and night time temps going below -10c.

[The PIT]

Sunny Sheffield down to 10.2C -2.1C below average. Rainfall up to 69.3mm 83.7% of the monthly average.

Big swing tonight on the modelling with a swing to much milder weather. Whether it's correct or not is another matter. Next few days will firm up the details. If it is correct t could lead to an average month.

[Roger J Smith]

EWP update ... 96 mm after 14 days (assuming near zero for 14th), then around 20 mm shown as average for next ten, so 116 mm by 24th-25th, the end of the month looks fairly wet although not quite the deluge that some places might get out of the circling low pressure areas; conservative estimate for the last six days would be 20 mm, could be 30-40 quite easily though. So on that basis, estimate is 136 mm with 50% confidence within range 116 to 156. 

These last few GFS runs are milder than what we were seeing, and would have an outcome of about 11.5 C. 

As to Octobers with warmer second halves than 1st to 16th, this is the complete list of 33 cases (from 1772) ... shows the final CET against the 1-16 CET ... in order of differentials and then chronological within same set. There were also 10 cases of no change in CET from 16th to 31st, the most recent 1980 (9.0) and 2004 (10.5), 2005 (13.1). ... possibly also 2015 which in my data dropped from 11.05 to 10.99. 

Since 43 years had either an increase or no change, the other 205 in the data set dropped by some amount, 1859 managed a full 4 deg drop from 13.6 to 9.6 at the end. 

1849 __ 9.2 (7.6) __ +1.6 ______ 1897 __ 9.9 (9.5) __ +0.4

1888 __ 7.9 (6.4) __ +1.5  ______ 1898 _ 11.3 (10.9) _+0.4

1867 __ 9.3 (8.2) __ +1.1  ______ 1927 _ 10.5 (10.1) _+0.4

1803 __ 9.3 (8.5) __ +0.8  ______ 1872 __ 8.4 (8.1) __ +0.3

1809 _ 10.2 (9.4) __+0.8  ______ 1884 __ 9.4 (9.1) __ +0.3

1952 __ 8.8 (8.1) __ +0.7  ______ 1988 _ 10.4 (10.1) _+0.3

2014 _ 12.5 (11.8) _+0.7  ______ 1779 _ 10.9 (10.7) _+0.2

1833 _ 10.1 (9.5) __+0.6  ______ 1826 _ 11.1 (10.9) _+0.2

1860 __ 9.8 (9.2) __ +0.6  ______ 1830 _ 10.4 (10.2) _+0.2

1925 _ 10.4 (9.8) __ +0.6  ______ 1899 __ 8.8 (8.6) __ +0.2

1838 __ 9.8 (9.3) __ +0.5  ______ 1936 __ 9.4 (9.2) __ +0.2

1853 _ 10.1 (9.6) __ +0.5  ______ 2009 _ 11.6 (11.4) _+0.2

1871 __ 9.8 (9.3) __ +0.5  ______ 1792 __ 8.8 (8.7) __ +0.1

1904 __ 9.7 (9.2) __ +0.5  ______ 1789 __ 8.6 (8.5) __ +0.1

1923 __ 9.7 (9.2) __ +0.5  ______ 1864 __ 9.8 (9.7) __ +0.1

1977 _ 11.8 (11.3) _+0.5  ______ 1877 __ 9.3 (9.2) __ +0.1

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1989 _ 11.7 (11.6) _ +0.1

--- --- --- --- --- --- --- --- --- --- --- -- 2020 _ 10.5 (10.4) _ +0.1

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

==============================================================

Has to be said that this is not the most encouraging list of analogues for a winter forecast. 

Note _ have edited in the 2020 result which barely makes this list. 

 

 

 

Edited November 2, 2020 by Roger J Smith

[damianslaw]

2 hours ago, The PIT said:

Sunny Sheffield down to 10.2C -2.1C below average. Rainfall up to 69.3mm 83.7% of the monthly average.

Big swing tonight on the modelling with a swing to much milder weather. Whether it's correct or not is another matter. Next few days will firm up the details. If it is correct t could lead to an average month.

Models showing rather average conditions, some milder uppers briefly into southern, central parts, quickly mixed out, and we end up under uppers quite normal for mid-late October. Lots of cloud and rain around which may mean temps don't fall much in the night helping to keep CET values up, but maxima look nothing to write home about. 

At the half way stage and looking at the longer range output a very high chance we will end up with a below average month, could it be the coldest relative to average since last October?

[The PIT]

Sunny Sheffield down to 10.1C -2.1C below average, Rainfall up to 69.6mm 84.1% of the monthly average.

Looking at overnights model run suggests that there won't be any real prolonged downward or upward pressure which suggest to me an average month is  a possibility. Of course it's too far out to so this is speculation really.

I wonder if there will be enough rain for us to end over 100mm again for the fourth time this year.

[cheeky_monkey]

On 15/10/2020 at 08:25, cheeky_monkey said:

cloudy Edmonton is at 6.8c which is +1.7c above normal..after a warm start to the month winter has arrived so watch the average tank over the next week as we start running into a fair few ice days and night time temps going below -10c.

snowy Edmonton has lost 0.5c in just one day now down to 6.3c and the real cold does not kick in until overnight...i believe we could be below normal for the month by the end of the weekend

[summer blizzard]

We dropped to 10.8C today i believe, the coolest first half since 2012.

CET might fall a bit more to the 19th before models suggest the trough from the south west makes an appearance (bringing a brief period of tropically sourced air). The last third has seen modelling bounce around a lot but the latest guidance largely limits any upward pressure to the 19th-23rd and as Roger alludes to only 10-20% of October's have seen a warmer or equal second half. 

 

[Scorcher]

On 13/10/2020 at 17:29, Relativistic said:

The answer to your questions should be very obvious from the original post.

No it makes zero sense to me. No traditional westerly onslaught? I don't see how what we have had is any more interesting than that. Synoptics matter little if the conditions are simply cool, cloudy and often wet as it's often been this month. How is that interesting?

[Roger J Smith]

For continuity, I will try to post these if they don't appear the usual way ... 

 

10.8c to the 15th

0.6c below the 61 to 90 average
1.0c below the 81 to 10 average

___________________________

Current high this month 11.7c to the 7th
Current low this month 10.7c to the 1st

 

[Summer Sun]

10.7c to the 16th

0.7c below the 61 to 90 average
1.0c below the 81 to 10 average

___________________________

Current high this month 11.7c on the 7th
Current low this month 10.7c on the 1st & 16th

[Scorcher]

Yet more murk and drizzle here right now. Makes me all the more puzzled why some are calling this an 'interesting' October.

Possibly the worst, most boring October I can recall.

Edited October 17, 2020 by Scorcher

[The PIT]

The weather is just more than one single day of grey rubbish. It's interesting because of the synoptic patterns at the moment. Sadly we won't probably see them in winter when we would have a snow fest out of it,

Sunny Sheffield down to 9.9C -2.3C degrees below normal. Rainfall unchanged and the first day since the 1st of the month where there hasn't been measurable rain.

Looking at the local forecast and this suggests we will about the same value by next weekend which will reduce the deficit to around  -1.4C

[Roger J Smith]

EWP update ... 98 mm so far (assuming none added to 15th tracker), about 35 mm showing as an average for days 1-10, and maps for 27th to 31st showing potential for 20-30 mm more then. It adds up to about 153-163 mm, 50% confidence 140 to 185, outside chance of threatening the record if the various systems perform to max. 

Annual scoring race will very likely remain similar as most of the top scoring forecasters have low to medium scores almost guaranteed now, Twilight moves a bit further ahead of Godber1 and Reef, Mulzy and mb018538 would make modest moves up the table, also Don moves ahead slightly. Most of the highest scores likely will be going to either low-ranked or occasional (or in one case new) forecasters who have no chance of overtaking even 25th to 30th place with their scores this month. I ran the scores for 130 mm but can see that any value above that will have almost the same results, as there were few forecasts above 140 mm. 

The forecasts near top end of the list don't score well for 130 mm but would do quite well for anything over 150, so there's a lot of range for them, but only limited range for scoring changes (from my 130 mm scoring) for most of the field. Our consensus was 107 mm showing some skill as normals are 100-104 mm for recent intervals. 

As to the CET, can't foresee much change in that, a slight rise seems likely then fluctuations within a narrow range, will most likely end up close to where it is now. 

[damianslaw]

Expect CET to stay fairly static over next few days, perhaps a slight rise, too far off to say how things may pan out during last week, but no obvious signal for anything particularly mild or cold so a very near average month looking probable, perhaps a greater than normal chance of going below the 61-90 mean given we are already at this value, however, perhaps lesser chance of being colder than last October. A cold high pressure theme by months end though could see us rival last year easily.

[summer blizzard]

Outlook to the 19th would see us perhaps fall to 10.6C then perhaps a rise to the 22nd to 10.8C then another slow fall to the 27th. Still a chance of beating last year after corrections however those in the 10.0-10.5C range are probably looking best.

[Scorcher]

10 hours ago, The PIT said:

The weather is just more than one single day of grey rubbish.

That is exactly the point for me- it has been A LOT more than one day of grey rubbish. Almost relentless.

[ItNeverSnowsInWindsor]

12 hours ago, Summer Sun said:

10.7c to the 16th

0.7c below the 61 to 90 average
1.0c below the 81 to 10 average

___________________________

Current high this month 11.7c on the 7th
Current low this month 10.7c on the 1st & 16th

I don’t think the Met Office had September or October as finishing in below average temperatures as their ‘climatology’ charts always favour above average temperatures. 

Great to see a break from the consensus for a change!