December 2017 C.E.T. forecasts -- start of 2017/18 competition year -- and an optional precip contest begins

[ItNeverSnowsInWindsor]

3 hours ago, Don said:

Looks like the chances of a colder than average December are fading fast.......

Not according to the latest GFS 6z run and the Met office last update

[Summer Sun]

4.2 to the 12th

0.7 below the 61 to 90 average

0.9 below the 81 to 10 average

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Current high this month 6.9 to the 7th

[The PIT]

Sunny Sheffield down to 3.9C -2.1C below normal. rainfall 11.3mm 13% of average.

[Chris.R]

I forgot to post in here the last few days so here goes. 

 4.8°C here, 0.7°C below the 1981-2010 average. 

[The PIT]

Just a question of how much damage next weeks mild spell does to the cet and whether the cold spell turns up or not next weekend. Sadly too far out too be reliable so could disappear on the next few runs.

[Optimus Prime]

On ‎06‎/‎12‎/‎2017 at 20:37, Optimus Prime said:

Well it averages 1.8c for the period 8-15th. Mid month will be around 3.8°c. Not overly below normal. The coldest since 2012. 

Looking remarkably good that.

[North-Easterly Blast]

We are certainly going to see the first half of December 2017 being below average for the CET.  Next week a few milder days are probable which will put the CET back up into the 4s, but beyond that the final part of the month is still up for grabs, with a range of outcomes in the output atm.

[Summer Sun]

4.0 to the 13th

0.9 below the 61 to 90 average

1.1 below the 81 to 10 average

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Current high this month 6.9 to the 7th

[BornFromTheVoid]

Rolling CET Anomaly to 81-10 rolling avg... (Daily Avg: Anomaly to 81-10 daily avg)

3.9C to the 14th... -1.1    (3.2: -1.2)    
3.9C to the 15th... -1.1    (3.5: -1.1)   
3.8C to the 16th... -1.2    (1.8: -2.8)   
3.9C to the 17th... -1.1    (4.9: +0.5)    
4.0C to the 18th... -0.9    (6.5: +2.1)   
4.4C to the 19th... -0.5    (11.0: +6.7)    
4.6C to the 20th... -0.2    (10.0: +6.3)   
4.8C to the 21st... +0.0    (7.9: +3.7)  
5.0C to the 22nd... +0.3    (10.0: +5.5)    
5.1C to the 23rd... +0.3    (5.5: +0.8)

A pretty impressive mild spell is now forecast for mid next week. If it comes off, the CET will very quickly move back above average, with a few daily records under threat too.

[The PIT]

Sunny Sheffield down to 3.7C -2.3C below normal. Rainfall 27.3mm 31.4% of average.

[damianslaw]

6 hours ago, BornFromTheVoid said:

Rolling CET Anomaly to 81-10 rolling avg... (Daily Avg: Anomaly to 81-10 daily avg)

3.9C to the 14th... -1.1    (3.2: -1.2)    
3.9C to the 15th... -1.1    (3.5: -1.1)   
3.8C to the 16th... -1.2    (1.8: -2.8)   
3.9C to the 17th... -1.1    (4.9: +0.5)    
4.0C to the 18th... -0.9    (6.5: +2.1)   
4.4C to the 19th... -0.5    (11.0: +6.7)    
4.6C to the 20th... -0.2    (10.0: +6.3)   
4.8C to the 21st... +0.0    (7.9: +3.7)  
5.0C to the 22nd... +0.3    (10.0: +5.5)    
5.1C to the 23rd... +0.3    (5.5: +0.8)

A pretty impressive mild spell is now forecast for mid next week. If it comes off, the CET will very quickly move back above average, with a few daily records under threat too.

Mmm think there are over estimations here, clearer skies will allow  quite cool minima I would imagine, cancelling out the milder max. Won't last long either.

 

[Summer Sun]

4.0 to the 14th

1.0 below the 61 to 90 average

1.0 below the 81 to 10 average

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Current high this month 6.9 to the 7th

[NorthYorksWeather]

2.4c here to the 14th, 1.8c below the 1981-2010 average.

Small drop possible before a rise back towards average from next week.

[The PIT]

Sunny Sheffield down to 3.6C -2.3C below normal. Rainfall 31mm 35.7% of average.  Another drop for today and tomorrow likely then up up and away.

[Chris.R]

 4.7°C here, 0.7°C below the 1981-2010 average. 

 Last night, evaporative cooling giving some unexpected snow has meant that the mean is a bit lower than it would’ve been otherwise. 

[snowray]

So by the look of things 2nd half of Dec will likely turn out milder than the 1st half. Always seems that way round in December, when was the last time it was milder in the 1st half and a lot colder in the 2nd half of the month? Not recently I expect.

[Matthew.]

8 hours ago, snowray said:

So by the look of things 2nd half of Dec will likely turn out milder than the 1st half. Always seems that way round in December, when was the last time it was milder in the 1st half and a lot colder in the 2nd half of the month? Not recently I expect.

2009

[Summer Sun]

3.9 to the 15th

1.0 below the 61 to 90 average

1.1 below the 81 to 10 average

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Current high this month 6.9 to the 7th

[snowray]

2 hours ago, Matthew. said:

2009

Ah right you are there Matthew, so its 8 years, thanks for that thought it had been quite some time ago.

Erm, but shouldn't it be getting colder though in late December on the whole, surely that should be the other way around, our winters are becoming stranger and stranger.

[The PIT]

No change Sunny Sheffield still at 3.6C -2.2C below normal. No further rain either.

[Summer Sun]

3.9 to the 16th

1.0 below the 61 to 90 average

1.1 below the 81 to 10 average

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Current high this month 6.9 to the 7th

[The PIT]

Sunny Sheffield down to 3.5C -2.3C below normal No change in rainfall

[NorthYorksWeather]

2.2c here to the 16th, 2.0c below the 1981-2010 average.

Expected a few rises early this week but looks like no rise until Wednesday.

Village half a mile down the road which is in a frost hollow close to sea level has a mean of just 1.3c so far for December.

[North-Easterly Blast]

On ‎15‎/‎12‎/‎2017 at 23:52, snowray said:

So by the look of things 2nd half of Dec will likely turn out milder than the 1st half. Always seems that way round in December, when was the last time it was milder in the 1st half and a lot colder in the 2nd half of the month? Not recently I expect.

Last year (2016) the second half of December was colder than the first half (7.0 first half, 5.0 second half).  In the 1990s and 2000s many Decembers were actually colder in the second half compared to the first half.  In recent years the Decembers of 2008, 2011, 2012, 2014, 2015 had a warmer second half than the first, with 2012 being the largest swing (2.5 to 7.1).

[Summer Sun]

3.9 to the 17th

1.0 below the 61 to 90 average

1.0 below the 81 to 10 average

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Current high this month 6.9 to the 7th