Met Office Hadley        1.7c       Anomaly     -1.8c Provisional to 5th

Metcheck                     1.79c     Anomaly     -2.36c

Netweather                  2.45c     Anomaly     -1.76c

Peasedaown St John    1.9c      Anomaly     -3.0c.     

 Of 8 locals to PSJ   1.32c. 

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Here is the latest CET tracker.

Notwithstanding comments I have seen elsewhere on the forum it is absolutely the case that we are experiencing a very significant cold spell. The first 10 days of January are expected to see a CET of 1.13C which is 3.2C below average. That is very significant.

The final 4 days of December saw a CET of 0.4C which is 4.2C below average. 

The CET for the 14 days from 28 December to 10 January will be around 0.9C which is 3.6C below average.

From Monday the CET starts to turn much milder and by 20 January I expect the CET (on current output) to rise to 3.88C. Still below average but not by that much. If (and it is a big if) the milder weather continues to the end of the month we could even end up slightly above average in the mid 4s.

Chart 1

Chart 2

Met Office Hadley        1.7c      Anomaly      -1.8c provisional to 6th

Metcheck                     1.55c    Anomaly       -2.66c

Netweather                  2.35c    Anomaly       -1.86c

Peasedown St John     1.4c      Anomaly       -3.5c.         

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Freezing mist and fog kept quite a few spots below zero today. I recorded a max of -0.7°C which is the lowest here since 2nd March 2018!

It was also a very cold night, could be an impressively low CET reading on the cards.

Gradually easing toward average in the coming days, then probably on the mild side for at least a time next week. Keep seeing runs that reintroduce chilly high pressure ridges, mind.

I must admit, I was a bit caught out by the spread of estimates this month - I was expecting to see more in the 1s and 2s!

My logic this month was, if it's ever going to be a sub-2°C, it's when you have a cold pattern in place coupled with cold signals for the mid-range and the possibility of cold(er) weather afterward associated with SSW response.

Now of course, those mid-range cold signals have been replaced with either mixed or mild depending on the model and run viewed. There was little sign of this at the end of December. Typical stuff.

I'm not without hope, though. The sudden stratospheric warming should continue to influence weather patterns for the remainder of the month and there are signs that tropical convection may not stay aligned with the La Nina base state, forcing higher pressure over Iberia, for more than a week.

All told, I'd not be surprised to see a 'banana' shape to this month's CET come the end of it.

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Met Office Hadley       1.3c      Anomaly     -2.2c Provisional to 7th

Metcheck                     1.33c   Anomaly     -2.82c

Netweather                  1.96c   Anomaly     -2.25c

Peasedown St John    1.4c      Anomaly     -3.5c. 

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Met Office Hadley         1.0c        Anomaly      -2.5c Provisional to 8th

Metcheck                       1.22c     Anomaly      -2.93c

Netweather                    1.81c     Anomaly      -2.4c

Peasedown  St John      1.4c      Anomaly       3.5c.   

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Met Office Hadley       1.0c       Anomaliy     -2.5c provisional to 9th

Metcheck                    1.11c     Anomaly      -3.04c

Netweather                 1.65c     Anomaly      -2.56c

Peasedown St John    1.3c      Anomaly       -3.6c.      

 

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Latest CET tracker shows the next four days should be somewhat less cold but by Friday things turn cooler again. Beyond that there is a lot of uncertainty but there are increasing signs of colder weather returning. 

At present the CET is predicted to be 3.22C by 24 January. However, I fully expect it could be a lot lower than that. 

The first 10 days of January will see a CET of just 0.9C which is 3.4C below average.

Chart 1

Chart 2

Wow that is amazing 

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What is more amazing is that Ive managed an air frost and I saw few small flakes of snow a couple of days ago!

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Model madness continues but there's an underlying increase in support for very cold air to make its way in from the northeast within the 3rd week of the month, likely as part of a cyclonic setup (i.e. unstable i.e. high snow potential).

The GFS 12z was one of the colder outcomes, giving me a CET estimate to 26th in the mid-1s °C.

Yet there have been a fair few much milder outcomes appearing too, which while a dwindling cluster in the ensembles, can't be ignored. Those lift my CET estimate right up into the 3s or even 4s °C!

 

Funny really - coldest opening 10 days in the CET series in 128 years, while down here it's been nothing of much note (overall) and about half the days reached close to 5°C which is what I'd call 'very chilly' rather than cold.

No snow here either - but it did deliver a rare subzero maximum and one of the only ones I can recall with no snow cover. So it's had its moments! 

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GW I must say am a little surprised that the CET was as high as that for the first ten days of 2010. I remember it as being a solidly sub zero CET period from my own recollections of the weather at the time/following the late Philip Eden's daily CET updates which he used to do back then.
Likewise 1997 and 2009 had bitter starts to January with several ice days at least IMBY. There must have been some mild days mixed in that I am forgetting!

Coldest since 1893. That's unbelievable,  and barely a flake of snow for over half the country. 

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Yes, I am also very surprised at those statistics. My memories of early January 2010 was that they were brutally cold with bitterly cold nights and sub-zero days, with that snowmaggedon event on 4-5 January. This year has seen overnight frosts, but most of the days have just about creeped above freezing. I recognise, I'm talking from a local perspective, but surely it was similar for most places.

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This was commented on in the "worst cold spell" thread below

It looks very much that the table compared mean temperatures in 2020 with the maximum temperatures for other years

1963 for instance should say -0.57

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I've since confirmed that GW's stats were awry - probably is a comparison with historical mean max CET as you say.

Means for the opening 10 days provisionally place 2021 near the bottom of a long list of years since 1772 that were 1°C or below:

1814: -2.97°C
1795: -2.59°C
1820: -2.48°C
1789: -2.19°C
1864: -2.09°C
1861: -2.00°C
1841: -1.95°C
1893: -1.93°C
2010: -1.90°C
1894: -1.79°C
1811: -1.78°C
1777: -1.45°C
1879: -1.19°C
1774: -1.05°C
1891: -1.05°C
1941: -0.77°C
1784: -0.68°C
1997: -0.65°C
1963: -0.57°C
1780: -0.56°C
1887: -0.43°C
1979: -0.40°C
2009: -0.37°C
1842: -0.31°C
1802: -0.30°C
1794: -0.14°C
1850: -0.12°C
1868: -0.11°C
1799: -0.09°C

1895: 0.01°C
1985: 0.07°C
1786: 0.09°C
1970: 0.22°C
1871: 0.27°C
1778: 0.27°C
1854: 0.29°C
1931: 0.34°C
1867: 0.42°C
1815: 0.55°C
1849: 0.58°C
1918: 0.66°C
1773: 0.66°C
1908: 0.67°C
1835: 0.71°C
1921: 0.75°C
1967: 0.81°C
1833: 0.87°C
2021: 0.90°C
1940: 1.00°C

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He edited the "since 1893" bit out of his post, so it looks like that wasn't true as others have suggested.

Certainly here, not only have we not had a single flake of snow this month, and only one visible hoar frost, but the lowest temperature has only been -2.3C (last night) and the lowest maximum wasn't an ice day (+0.5C, on the 7th January). Still has been a notable cold spell, but only memorable for the facts and figures, and not for what's outside the window. 

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That makes more sense. Whilst this January has been cold-feeling so far, it seemed a bit too stange for it to be colder than months like 2010 and 1979 etc.

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According to this link: https://www.metoffice.gov.uk/hadobs/hadcet/cetdl1772on.dat

CET First 10 days of January 2010: -1.90C

CET First 10 days of January 1979: -0.45C

CET First 10 days of January 1963: -0.57C

Damn, Stormchaser beat me to it!

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Even so there's been only 4 colder starts to Jan since 1979.
That's quite something

Met Ofice Hadley      1.2c      Anomaly     -2.4c  Provisional to 10th

Metcheck                  1.37c    Anomaly     -2.79c

Netweather               1.71c    Anomaly     -2.5c

Peasedown St John   1.3c     Anomaly     -3.6c

 

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Met Office Hadley      1.6c     Anomaly     -2.0c   Provisional to 1th

Metcheck                   1.85c   Anomaly     -2.30c

Netweather                2.16c   Anomaly    -2.05c

Peasedown St John   1.8c     Anomaly    -3.1c.     

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Thanks for that detail James. Amazing, in fact, to see 1940's first 10 so far down the table.

Reminds us again how the whole pattern can shift- edit: 1987 too.

I guess we'll be above 2 in a day or so, but if the models keep showing the same scene (although there are hiccups possibly developing) we could drop to close to zero by month's end. That would be an interesting start to the 2021 profile.

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This makes more sense . Very rare for GW to get it wrong though.

 

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Met Office Hadley        1.9c       Anomaly      -1.7c Provisional to 12th

Metcheck                      1.87c    Anomaly      -2.28c

Netweather                   2.42c    Anomaly      -1.79c

Peasedown St John     2.3c      Anomaly       -2.6c.                  

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