C.E.T. forecasts for December 2015 (start of 2015-16 competition year)

[BornFromTheVoid]

With a minimum of 9.0C and maximum of 13.8C, yesterday beat the daily record by 0.6C (provisionally).

The minimum today is 11.5C (0.1C below the record mean!), while maxima look like reaching the mid 14s, so an increase on tomorrows update to 9.5C looks likely.

After that, the 06z GFS has the CET at:

9.7C to the 18th (12.4: +8.0) [Record High: 11.8C]
9.8C to the 19th (12.5: +8.2) [Record High: 11.6C]
9.9C to the 20th (10.6: +6.9) [Record High: 11.1C]
9.9C to the 21st (10.9: +6.7) [Record High: 11.4C]
10.0C to the 22nd (10.6: +6.1) [Record High: 11.6C]
9.9C to the 23rd (8.3: +3.6)
9.9C to the 24th (9.1: +4.4)
9.9C to the 25th (10.3: +5.8] [Record High: 10.4C]
9.8C to the 26th (7.1: +2.8]

While a new daily record today is almost certain, the maximum today needs just 14.4C to get the daily average rounded up to 13.0C, to make it the first 13.0C+ December day on record. Taking the forecast to the 22nd to be reliable, the final 9 days of the month would have to average:

6.7C to reach 9.0C
3.6C to reach the current record of 8.1C
-8.4C to reach the 81-10 average of 4.6C

[Milhouse]

Quite likely will end up being the greatest positive anomaly for any month on record.

[Duncan McAlister]

Looks to me like the last couple of GFS op runs would take December back into the 8s merely with near average conditions over the final few days, but still too early to be confident. Worth reiterating that in Scotland temperatures have been much closer to average throughout the month.

[Terminal Moraine]

2 hours ago, Scorcher said:

Well to put that in perspective, it was 14C at Manchester Airport at 1 am. I'm pretty sure it would have been above 10C even at altitude in Derbyshire at the same time too.

11.7 c here shortly after 0100. That's 6.5c above the average December maximum!

[The PIT]

Sunny Sheffield up to 8c and unless it gets suddenly cold tonight 8.3C tomorrow.

[Don]

A truly horrifying month in my view and along with November has completely ruined 2015 as being a near average year......  Not looking forward to 2016 weather wise, either.  

Edited December 17, 2015 by Don

[BornFromTheVoid]

16 minutes ago, Don said:

A truly horrifying month in my view and along with November has completely ruined 2015 as being a near average year......  Not looking forward to 2016 weather wise, either.  

Thanks to November and December, this year will end up in the warmest 10% of years on record, somewhere between the 26th and 29th warmest out of 357 years. All the more impressive considering only 4 months will be above the 81-10 average.

[BornFromTheVoid]

7 minutes ago, Thunderbolt_ said:

A bit ambitious, but what would it take to beat November?

8.4C, roughly.

[Roger J Smith]

Something else to track, and it appears that 2015 will easily take top spot in this list:

Final edit (1st Jan 2016) _ Have used final values which blow away all previous data.

DAYS WITH CET AT or ABOVE 10.0

 

18 __ 2015

9 ___ 1974

8 ___

7 ___ 1842, 1898

6 ___ 1828, 1979, 1985

5 ___ 1852, 1856, 1918, 1987, 2000

4 ___ 1775, 1820, 1857, 1866, 1888, 1934, 1994

3 ___ 1772, 1827, 1831, 1843, 1848, 1867, 1868, 1873, 1900, 1921, 1932, 1941, 1942,

_______ 1948, 1954, 1956, 1971, 1986, 1997, 2007

2 ___ 1778, 1779, 1781, 1795, 1833, 1834, 1847, 1876, 1882, 1922, 1925, 1951, 1953,

_______ 1961, 1964, 1977, 1978, 1980, 1983, 1988, 1991, 1993, 1998, 2006, 2014

1 ___ 1787, 1789, 1793, 1794, 1797, 1803, 1806, 1817, 1821, 1824, 1835, 1836, 1849,

_____ 1850, 1851, 1859, 1862, 1865, 1878, 1897, 1899, 1901, 1902, 1904, 1906, 1907,

_____ 1911, 1912, 1916, 1924, 1928, 1929, 1931, 1938, 1939, 1949, 1955, 1958, 1965,

_____ 1967, 1972, 1989, 1992, 1995, 2002, 2008, 2011

 

CONSECUTIVE DAYS AT or ABOVE 10.0 (does not include any in Nov or Jan)

6  __ 2015

5 ___ 1856 (6th-10th) and 2015 (26th-30th)

4  __ 1775, 1866, 1888, 1918. 2015 (5th-8th)

3 ___ 1828, 1867, 1868, 1898, 1932, 1941, 1942, 1974, 1974, 1985, 1986, 1987, 1994, 1997

2  ___ 1820, 1827, 1828, 1831, 1834, 1842, 1842, 1843, 1847, 1848, 1852, 1852, 1876, 1882, 1898, 1921, 1922, 1925, 1934, 1934, 1954, 1956, 1961, 1964, 1971, 1974, 1977, 1978, 1979, 1979, 1979, 1985, 1987, 1991, 1998, 2000, 2000, 2007, 2015 (2nd-3rd)

_____________________________________________________

251 days before this year reached 10.0 in 110 of 243 years (including one that has a mean of 2.8 but no daily data, 1786) ... of those 251 days, 139 were in groups of 2 to 5 consecutive days.

In the lists above, years that appear twice (or three times) have more than one streak of consecutive days. While doing this table, I noticed that one of these days occurred within two weeks of record cold (1859) and a few other days were in rather cold months, but normally they only occur in relatively mild months.

Edited January 1, 2016 by Roger J Smith

[Weather26]

9.5c to the 17th

4.7c above the 61 to 90 average

4.6c above the 81 to 10 average?

[The PIT]

A cooler day than forecast. Still mild at just 8.9C !!!!!!!

[BornFromTheVoid]

At 12.8C, yesterday was provisionally the 2nd mildest December day on record, 1.2C warmer than the previous record for December 17th and the latest to record a CET above 12.0C.

The minimum today is 10.4C, while maxima look like reaching the low to mid 14s, so we should see an increase to 9.7C on tomorrows update.

After that, the 06z GFS has the CET at:

9.7C to the 18th (12.4: +8.0) [Record High: 11.8C]
9.9C to the 19th (13.1: +8.8] [Record High: 11.6C]
9.9C to the 20th (11.2: +7.5) [Record High: 11.1C]
10.0C to the 21st (10.6: +6.4) [Record High: 11.4C]
10.0C to the 22nd (11.0: +6.5) [Record High: 11.6C]
10.0C to the 23rd (8.8: +4.1)
9.9C to the 24th (8.7: +4.0)
9.9C to the 25th (10.6: +6.1) [Record High: 10.4C]
9.8C to the 26th (7.6: +3.3)

To beat the record high for today (11.8C) we need the maximum to be over 13.3C, which seems very likely.
To set a new record for the latest day averaging above 12.0C, we need 13.7C at least.
Then the 19th has the chance of setting the latest day of 13C or more, the mildest December day on record and the largest December daily anomaly on record.

At this stage, I'd estimate a finishing value of between 8.8C and 9.8C before corrections, and 8.3C to 9.8C after corrections.

[Don]

10 minutes ago, BornFromTheVoid said:

At this stage, I'd estimate a finishing value of between 8.8C and 9.8C before corrections, and 8.3C to 9.8C after corrections.

If we end up with a final figure of 9.8C, that will be one hell of a record.  1.7C higher than the previous?!

[Weather26]

29 minutes ago, BornFromTheVoid said:

At 12.8C, yesterday was provisionally the 2nd mildest December day on record, 1.2C warmer than the previous record for December 17th and the latest to record a CET above 12.0C.

The minimum today is 10.4C, while maxima look like reaching the low to mid 14s, so we should see an increase to 9.7C on tomorrows update.

After that, the 06z GFS has the CET at:

9.7C to the 18th (12.4: +8.0) [Record High: 11.8C]
9.9C to the 19th (13.1: +8.8] [Record High: 11.6C]
9.9C to the 20th (11.2: +7.5) [Record High: 11.1C]
10.0C to the 21st (10.6: +6.4) [Record High: 11.4C]
10.0C to the 22nd (11.0: +6.5) [Record High: 11.6C]
10.0C to the 23rd (8.8: +4.1)
9.9C to the 24th (8.7: +4.0)
9.9C to the 25th (10.6: +6.1) [Record High: 10.4C]
9.8C to the 26th (7.6: +3.3)

To beat the record high for today (11.8C) we need the maximum to be over 13.3C, which seems very likely.
To set a new record for the latest day averaging above 12.0C, we need 13.7C at least.
Then the 19th has the chance of setting the latest day of 13C or more, the mildest December day on record and the largest December daily anomaly on record.

At this stage, I'd estimate a finishing value of between 8.8C and 9.8C before corrections, and 8.3C to 9.8C after corrections.

So we could be in with a shout of beating the Christmas day record-Blimey! 

[BornFromTheVoid]

6 minutes ago, Don said:

If we end up with a final figure of 9.8C, that will be one hell of a record.  1.7C higher than the previous?!

With regard to the 81-10 average, the largest positive anomaly on record is +3.7C from June 1846 (18.2C) To beat that, December only needs to finish on 8.4C. A December of 9.8C would not only be the mildest December by 1.7C, but also the most positive anomaly of any month by 1.5C!

However, the positive anomaly isn't the whole story. Using the standard deviation for each month (from 1659 to 2014), December's is 1.7C, the 3rd highest of any month after February (1.8C) and January (2.0C). This means that December tends to have more variable and large anomalies than most of the other months. Taking this into account, a 9.8C December would be 3.0 standard deviations from average. Meanwhile, the standard deviation for June is just 1.1C, the 2nd lowest of all months, which also means the June 1846 anomaly of 3.7C is 3.4 standard deviations from normal, making that a more exceptional/unusual month than even a December of 9.8C.

These are just some ways of looking at it though, there are other interpretations!

[BornFromTheVoid]

The Christmas period is much cooler on the 12z, and the CET would be down to about 9.4C to the 27th

[Nick L]

Yes looking increasingly possible that there will be quite a cool down after Christmas. This is like Dec 2010 in reverse!

[reef]

2 hours ago, Nick L said:

Yes looking increasingly possible that there will be quite a cool down after Christmas. This is like Dec 2010 in reverse!

Its GFS vs ECM though, both completely different. Unfortunately, I know which I would back at that time range.

To be honest though, I don't want it to get cooler now this side of the new year. We might as well have this disgusting month up there miles above the existing record to show what an abomination it has been.

[The PIT]

Yes an FI brief cool down before turning very mild once again. Still in FI so any cool down could well be gone in a few days times. Anyway a record breaking December in the bag

[The PIT]

Sunny Sheffield at 8.5C good chance of 8.7C tomorrow

[Summer Sun]

9.7c to the 18th

4.9c above the 61 to 90 average

4.8c above the 81 to 10 average

 

[Bullseye]

The Met Office say this is the 4th warmest first half of December.

[Roger J Smith]

34 minutes ago, Bullseye said:

The Met Office say this is the 4th warmest first half of December.

Probably for the entire U.K., I would imagine. However, even the CET did not break free of its three closest rivals until the 16th, so depending on whether the Met Office considers the first half to be 1-15 or 1-16, the final CET figures may agree with that. However, as of today if we estimate 9.8 C as the figure, the CET is well clear of the nearest previous values which are a degree or more lower. As some parts of the north have not been as mild, this month may not finish warmest for the entire country, but it seems very likely that it will for the CET zone and the south in general.

[Bullseye]

Yes your right was for UK as a whole, from the the graph it looks like North Scotland is running around average compared to rest of Scotland and more so Wales/England. The Met Office said it was between the 1-14 period running at 3.2 above average.

[Weather-history]

May 1996 had a CET of 9.1C, come this December beat this?