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

[BornFromTheVoid]

The minimum today is 6.2C while maxima look like reaching the low 10s, so a drop to 10.1C is likely on tomorrows update.

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

9.9C to the 11th (7.4: +3.2)
9.6C to the 12th (7.3: +3.1)
9.5C to the 13th (8.1: +3.5)
9.5C to the 14th (9.3: +4.9)
9.5C to the 15th (9.7: +5.1)
9.4C to the 16th (7.8: +3.2)
9.3C to the 17th (8.3: +3.9)
9.4C to the 18th (10.2: +5.8]
9.5C to the 19th (11.0: +6.7) [Record High: 11.6C]

So, provisionally the warmest first 10 days of December on record, and warmest first half looking quite likely now.

If we are on 9.5C to the 15th, the last 16 days of the month would have to average around:

0.1C to reach 4.6C (81-10 average)
0.9C to reach 5.0C
2.8C to reach 6.0C
4.7C to reach 7.0C
5.3C to reach 7.3C (Top 10)
6.1C to reach 7.7C (Top 3)
7.0C to set a new warmest month (8.2C)
 

[cheeky_monkey]

has there ever been a December where no days have come in below the average CET value?

[reef]

16 minutes ago, BornFromTheVoid said:

The minimum today is 6.2C while maxima look like reaching the low 10s, so a drop to 10.1C is likely on tomorrows update.

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

9.9C to the 11th (7.4: +3.2)
9.6C to the 12th (7.3: +3.1)
9.5C to the 13th (8.1: +3.5)
9.5C to the 14th (9.3: +4.9)
9.5C to the 15th (9.7: +5.1)
9.4C to the 16th (7.8: +3.2)
9.3C to the 17th (8.3: +3.9)
9.4C to the 18th (10.2: +5.8]
9.5C to the 19th (11.0: +6.7) [Record High: 11.6C]

So, provisionally the warmest first 10 days of December on record, and warmest first half looking quite likely now.

If we are on 9.5C to the 15th, the last 16 days of the month would have to average around:

0.1C to reach 4.6C (81-10 average)
0.9C to reach 5.0C
2.8C to reach 6.0C
4.7C to reach 7.0C
5.3C to reach 7.3C (Top 10)
6.1C to reach 7.7C (Top 3)
7.0C to set a new warmest month (8.2C)
 

I think top 10 is pretty much a cert now. Although there's always a chance of a cold snap later in the month, there doesn't look to be any strong signals other than more of the same. A brief cold snap might ultimately stop the record going but this month already has the distinct feel of being a record-breaker. If we somehow get to the 19th at 9.5C then a mean of 6.0C would see us reach 8.2C, which is quite easily doable even with a cooldown.

[BornFromTheVoid]

24 minutes ago, cheeky_monkey said:

has there ever been a December where no days have come in below the average CET value?

Depends on what average you use. Having a quick look with the 81-10 average, it seems the closest was 1934, which only had 1 day below the 81-10 average. 2013 was also close, only having 2 such days.

To the opposite extreme, we've had 3 Decembers with every day below the 81-10 average, 1786, 1890 and 1933

[The PIT]

Sunny Sheffield 8.9C  my CET guess of 6.5C looks miles too low doesn't it.

[Roger J Smith]

On December-02-15 at 10:39 AM, Roger J Smith said:

(sorry, had to quote to block copy the data, this new format seems to be missing a few features so far ...)

 

WARMEST FIRST HALF to 20th OF DECEMBER CET 1772-2014

expanded to 20th, includes all cases where years reach top 16 any day of countdown

_____________________________________________________

 

Rank _ Year ___CET 1-15___1-16___1-17___1-18___1-19___1-20 (rank)____1-31 (rank)

 

01 ___ 1898 __ 9.15 __ 9.03 (1) _ 9.05 (1) _ 9.15 (1) _ 8.96 (1) _ 8.67 (2) ___ 7.3 __ 9 (t)

02 ___ 2000 __ 9.08 __ 8.68 (4) _ 8.29 (6) _ 8.03 (11)_ 7.92 (9t)_7.90 (8) ___ 5.8 _ 53 (t)

03t___ 1934 __ 9.05 __ 9.02 (2) _ 8.91 (2) _ 8.82 (2) _ 8.83 (2) _ 8.83 (1) ___ 8.1 __ 1 (t)

03t___ 1918 __ 9.05 __ 8.96 (3) _ 8.70 (3) _ 8.46 (4) _ 8.23 (3t)_ 7.97 (7) ___ 6.9 _ 14 (t)

05 ___ 1979 __ 8.69 __ 8.56 (5) _ 8.38 (4t)_ 8.49 (3) _ 7.93 (7t)_ 7.66 (12)___ 5.8 _ 53 (t)

06t___ 1831 __ 8.47 __ 8.35 (7t)_ 8.26 (7) _ 8.13 (9) _ 7.93 (7t)_ 7.81 (9) ___ 5.8 _ 53 (t)

06t___ 1948 __ 8.47 __ 8.35 (7t)_ 8.25 (8t)_ 8.06 (10)_ 7.73 (13t)_7.48 (xx)__ 5.7 _ 64 (t)

08 ___ 1956 __ 8.41 __ 8.41 (6) _ 8.38 (4t)_ 8.23 (6) _ 7.91 (11) _ 7.60 (15)___ 5.7 _ 64 (t)

09 ___ 2006 __ 8.40 __ 8.23 (11)_ 8.06 (13)_ 7.86 (14)_7.63 (16)_ 7.36 (xx)___ 6.5 _ 25 (t)

10 ___ 1900 __ 8.38 __ 8.33 (9) _ 8.23 (11)_ 8.17 (8) _ 8.04 (5t)_ 8.07 (4) ____ 7.2 _ 11 (t)

11 ___ 1868 __ 8.27 __ 8.25 (10)_ 8.25 (8t)_ 8.19 (7) _ 8.04 (5t)_ 7.98 (5t) ___ 7.2 _ 11 (t)

12 ___ 1953 __ 8.25 __ 8.11 (13)_ 8.08 (12)_ 8.00 (12)_7.92 (9t)_ 7.70 (11) ___ 6.9 _ 14 (t)

13 ___ 1985 __ 8.11 __ 8.21 (12)_ 8.25 (8t)_ 8.28 (5) _ 8.23 (3t) _ 8.23 (3) ____ 6.3 _ 33 (t)

14 ___ 1852 __ 8.00 __ 7.86 (14)_ 7.90 (15)_ 7.71 (15)_ 7.73 (13t)_ 7.80 (10)___7.7 __ 3

15 ___ 1994 __ 7.97 _ 7.75 (16)_ 7.68 (16)_ 7.68 (17)_ 7.53 (xx) _ 7.34 (xx) ___ 6.4 _ 29(t)

xx ___ 1857 __ 7.70 _ 7.81 (15)_ 7.97 (14)_ 7.88 (13)_ 7.66 (15)_ 7.63 (13) ___ 7.3 _ 9(t)

xx ___ 1974 __ 7.70 _ 7.66 (xx) _ 7.52 (xx) _ 7.47 (xx) _ 7.47 (xx)_ 7.59 (14) ___ 8.1 _ 1(t)

xx ___ 1828 __ 7.25 _ 7.41 (xx) _ 7.60 (xx) _ 7.74 (16) _ 7.81 (12)_ 7.98 (5t) ___ 7.4 _ 7(t)

xx ___ 1827 __ 7.21 _ 7.23 (xx) _ 7.19 (xx) _ 7.42 (xx) _ 7.56 (xx) _ 7.51 (16)___ 6.9 _ 14 (t)

xx ___ 1733 __________________________ no daily data _______________________ 7.6 __ 4

xx ___ 1710 __________________________ no daily data _______________________ 7.5 __ 5(t)

xx ___ 1988 __ 6.73 __ 6.69 (xx) _ 6.58 (xx) _ 6.66 (xx) _ 6.75 (xx) _ 6.78 (xx)__ 7.5 __ 5(t)

xx ___ 1843 __ 6.92 __ 7.03 (xx) _ 6.99 (xx) _ 6.96 (xx) _ 6.98 (xx) _ 7.01 (xx)___ 7.4 __ 7(t)

xx ___ 1842 __ 7.26 __ 7.48 (xx) _ 7.46 (xx) _ 7.33 (xx) _ 7.19 (xx) _ 7.32 (xx)___ 7.2 __ 11(t)

xx ___ 1833 __ 6.80 __ 6.89 (xx) _ 6.93 (xx) _ 7.03 (xx) _ 7.15 (xx) _ 7.09 (xx)___ 6.9 __ 14(t)

 

(note, xx is any rank below 16th)

 

This is the updated list from 15th to 20th showing all cases that were top 16 on any day in the period, with their final ranks. Added since last time, all top 16 finishers that are not yet in the list. The table will be continued from ranks on 20th in two instalments later this month. (Ranks on 20th are in the second last column now).

 

Edited December 11, 2015 by Roger J Smith

[Lettucing Gutted]

17 hours ago, cheeky_monkey said:

has there ever been a December where no days have come in below the average CET value?

We came very close in December 2013.  Only 1 day, the 11th, was below the 1961-1990 monthly average and even then only by a whisker whilst the 6th and Christmas Eve equalled it.

On ‎06‎/‎12‎/‎2015 at 6:36 PM, I remember Atlantic 252 said:

 

my 7.1C looks too low, how could  I remember Atlantic 252 guess too low in a 'winter' month????????????? many will think

Even my "hot" 9C is looking shaky and too low already!  I wouldn't be surprised if we see a CET warm record smashed by the biggest amount since May 1833.

Edited December 11, 2015 by IHaveNoTrueFriendsNow!
Mistakes :)

[Summer Sun]

10.1c to the 10th

5.1c above the 61 to 90 average

4.8c above the 81 to 10 average

[BornFromTheVoid]

Min today of 5.5C, while maxima look like reaching the mid to high 8s, so a drop to 9.8C is likely on tomorrows update.

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

9.6C to the 12th (7.5: +3.3)
9.3C to the 13th (6.2: +1.6)
9.2C to the 14th (7.7: +3.3)
9.2C to the 15th (9.2: +4.6)
9.3C to the 16th (10.4: +5.8] [Record High: 10.8C]
9.4C to the 17th (10.7: +6.3) [Record High: 11.6C]
9.5C to the 18th (11.5: +7.1) [Record High: 11.8C]
9.6C to the 19th (11.7: +7.4) [Record High: 11.6C]
9.7C to the 20th (10.4: +6.7) [Record High: 11.1C]

From very mild to exceptionally mild next week it seems. A few records might be under threat, but a bit far away at this stage to place much faith in the forecast.
 

[BornFromTheVoid]

54 minutes ago, Thunderbolt_ said:

Is it ridiculous to think that we could get a December that is warmer than the exceptionally mild, third warmest November on record, in the same year?

It would take something quite extraordinary to beat November, I think it extremely unlikely that we could maintain near record breaking warmth for the whole month (which is what's required). Surely we'll see a run of even just slightly above average days at some stage? To go from a record warmest month of 8.1C to something over 9C would be ridiculous.

On average, (since 1772), the coldest daily average CET for December is -1.3C. The December with the mildest coldest day (if that makes sense!?) was 2013,  which had a coldest day of just 4.2C. The coldest day so far this month is a whopping 7.3C from the 9th. We're likely to beat that in the next few days, with the 13th forecast to average in the low 6s.

Below is the cumulative CET of the top 3 Decembers, the 81-10 average and 2015 so far (with the forecast values from the 11th to 20th).

Edited December 11, 2015 by BornFromTheVoid

[Milhouse]

All i seem to be seeing of late is the potential for record high CET values. Not even the atrocious end to July produced any record cold days? Interesting times.

[Scorcher]

Maybe us mild fans should be hoping for below average SSTs in the North Atlantic every winter....

Obviously this would not be ideal in summer, however. It does make you wonder though about how much impact the area of below average SSTs well out in the Atlantic actually does impact us, especially when you consider that in fact the waters closest to us have actually been above average recently.

[Roger J Smith]

11 hours ago, IHaveNoTrueFriendsNow! said:

Even my "hot" 9C is looking shaky and too low already!  I wouldn't be surprised if we see a CET warm record smashed by the biggest amount since May 1833.

From 9.5 on 20th, the GFS 21st to 27th at present looks to be in the 6-7 range which would suggest 8.7 by the 27th. So I think the odds favour you being high rather than low. I think it's appropriate that you will need a record high value to win the month. I have 7.4 which is the closest forecast to yours. So 8.2 as the outcome means a tie, anything above that and you take the month.

Not saying this is a two-man race yet because if the GFS proves to be too warm past mid-week we could see a steady slide down into the range where colder weather at the end of the month could conceivably drag the CET below 7.5. Looking at my table of top 16 months posted yesterday, quite a few contenders on the 20th dropped out of the running, for example 2000 dropped from 2nd on the 15th to 8th on the 20th and finished tied for 53rd. Only a few years such as 1843, 1974 and 1988 actually improved their CET after the 20th.

[AderynCoch]

Just read this thread for the first time this month. God what a depressing period we're going through. As if the egregiously mild November wasn't bad enough, we're suddenly heading for the warmest first half of December as well. Talk about adding insult to injury. I put down 7.0C to hedge my bets in the hope that it would be too high, but even that's looking wildly optimistic at the moment.

Really can't wait to see the back of this disgusting Euro High. People say it's normal for such a pattern to be difficult to shift but this is absolutely ridiculous.

Edited December 11, 2015 by AderynCoch

[Weather-history]

1 hour ago, Thunderbolt_ said:

I don't think it is the Atlantic SSTs. I think it has more to do with the very hot summer that Europe had. There is a lot of latent heat left over, so I assume that is promoting the Euro High, which is therefore keeping most of Western Europe exceptionally mild.

Why wasn't December 2003 exceptionally mild? That was a scorcher over Europe that summer. 

[sundog]

Is it not largely down to the super el nino??????  Seems a bit of a coincidence to me.

[Costa Del Fal]

1 hour ago, Thunderbolt_ said:

I don't think it is the Atlantic SSTs. I think it has more to do with the very hot summer that Europe had. There is a lot of latent heat left over, so I assume that is promoting the Euro High, which is therefore keeping most of Western Europe exceptionally mild.

Don't mean to be pedantic here and instead helpful for learning but not sure your use of the term latent heat is correct in this sense here. Latent heat as I know it refers to the heat absorbed or released in a change of phase such as solid to liquid.

Here is a useful link: http://www.britannica.com/science/latent-heat

as I understand it, it is the SST pattern under El Niño which drives a lot of the patterns we see. The science reveals very conflicting opinions on its influence over Europe. We are one of the furthers at from the Pacific where El Niños heart lies which doesn't help. Though the heat from the ocean is thought to help push the jet stream north especially over America. Typically a northerly jet seems to be flatter. When it's on a southerly track we often tend to see it amplified and more messy and when we get our better cold spells. Hence a more northerly jet (theoretically at least) over America means I'm not surprised downstream we see something similar generally and hence giving room for pressure to stay higher than normal to our south thus allowing the euro high to thrive essentially! 

This is how I see things without writing an essay on it but the science like on lots of things certainly conflicts and there isn't really a right or wrong view/answer IMO.

[Lettucing Gutted]

12 hours ago, Scorcher said:

Maybe us mild fans should be hoping for below average SSTs in the North Atlantic every winter....

Obviously this would not be ideal in summer, however. It does make you wonder though about how much impact the area of below average SSTs well out in the Atlantic actually does impact us, especially when you consider that in fact the waters closest to us have actually been above average recently.

I highly doubt this very mild pattern has been driven by the cold North Atlantic SSTS.  I believe it is the case of a potentially cold Atlantic driven pattern being completely overridden by a very mild Hyper El Nino and +PDO driven pattern in the Pacific.  After looking at the SST anomaly charts I can even see that there is still more warm anomalies than cold ones even in the North Atlantic which is reinforcing the very mild Pacific pattern with a +AO and +NAO.  I also believe Thunderbolt's theory of the latent heat from the hot Euro summer enhancing the Euro High.  That in turn is also bolstering the forcing from the Pacific.

8 hours ago, Costa Del Fal said:

Don't mean to be pedantic here and instead helpful for learning but not sure your use of the term latent heat is correct in this sense here. Latent heat as I know it refers to the heat absorbed or released in a change of phase such as solid to liquid.

Instead of the classical definition, I think Thunderbolt simply used the term Latent Heat as a quick way of saying that it was the residual heat in the ground from the hot summer in Europe that is heating the air and promoting the Euro High.

Edited December 12, 2015 by IHaveNoTrueFriendsNow!

[Weather-history]

On 20 November 2015 at 9:31 PM, Weather-history said:

Hard to believe we are still waiting for a December with a CET of 5.9C

And we are still going to wait. 

We could even up having three Decembers above 8.0C and yet not one at 5.9C which should be climatologically easier to achieve than 8.0C

[March Blizzard]

4 hours ago, Weather-history said:

And we are still going to wait. 

We could even up having three Decembers above 8.0C and yet not one at 5.9C which should be climatologically easier to achieve than 8.0C

That really is quite ridiculous. What an odd quirk!

[Backtrack]

Makes you laugh doesn't it. The fact that if the CET was to stay the way it was, it would come out on paper, just 0.7C colder than May 2015 and 1.1C warmer than April 2015.

[Summer Sun]

9.8c to the 11th

4.8c above the 61 to 90 average

4.6c above the 81 to 10 average

[BornFromTheVoid]

Minimum today of 3.5C, while maxima look like being around 12C, so a drop to 9.6C is likely on tomorrows update.

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

9.4C to the 13th (6.2: +1.6)
9.1C to the 14th (6.4: +2.0)
9.1C to the 15th (8.8: +4.2)
9.2C to the 16th (10.9: +6.3) [Record High: 10.8C]
9.4C to the 17th (12.7: +8.3) [Record High: 11.6C]
9.5C to the 18th (10.9: +6.5) [Record High: 11.8C]
9.6C to the 19th (10.3: +6.0)
9.5C to the 20th (7.8: +4.1)
9.5C to the 21st (9.2: +5.0)
 

Could we really be at 9.5C going into the last 10 days of the month? Seems remarkable to say the least. Also, the latest that a daily average greater than 12.0C has been recorded before is December 12th 1994, with 12.9C. The forecast value for the 17th would push that record on by 5 days.

[The PIT]

Sunny Sheffield at 8.3C slow fall until the middle of the week by the looks of things and then rising again possibly.  Good chance of recording our warmest ever December.

[Gustywind]

For me the records all but gone already, it's just how much we beat 8.1c by for me.