December CET

[Weather-history]

Hadley CET is -1.8C up to the 4th

A remarkable 9th consecutive day where the mean is below 0C

26th November-4th December CET: -1.9

Looks like the longest such spell since February 1991!

Edited December 5, 2010 by Mr_Data

[damianslaw]

Hadley CET is -1.8C up to the 4th

A remarkable 9th consecutive day where the mean is below 0C

26th November-4th December CET: -1.9

Looks like the longest such spell since February 1991!

Gosh can't quite believe the past 9 days have beaten the CET temps we saw in the first 9 days of January this year... this is a bone chilling spell of weather.

Here the last time we saw 2 degrees was on the 25th November - the average max for late nov/early dec here is about 7 degrees, the anomalies are quite something else for the time of year.

[North-Easterly Blast]

With no let-up on the overnight model outputs we could be looking at a record-breaking cold December at this rate.

Thanks for the pointer that February 1986 was the 4th not 3rd coldest month of the C20th. I totally agree with T A Hartley that this is the forgotten month of the C20th. It was astonishingly cold, but often bone dry until 01st March:

February. Very cold (-1.1C CET), with frequent light snowfalls. The second coldest February of the century (after 1947), and third coldest month [edit. fourth]. The month was similar to January 1963 in being a completely blocked month, with a high centred over north Russia bringing some very cold air east. Winds were easterly for 23 days, and were of virtual calm for the remaining days. Easterly winds had already set in by the end of January. Snow cover was widespread in the east, where it was very dull: Cupar (Fife) registered only 41 hours sunshine all month. In the west it was very dry and sunny (144 hours sunshine on Anglesey; with no measurable rain at all in some western coastal sites). The lowest temperature was at Grantown-on-Spey, where it reached -21.2C on the 27th. The lowest temperature around Birmingham was -11.0C, at Elmdon, on the 21st, and the highest, just 3.8C on the 28th. Freezing rain in the north Midlands. Up to 50 mm of glaze was recorded on broken power lines at Buxton on the 2nd. Widdybank Fell, at 513 m above sea level in County Durham, remained beneath freezing all month, and had a total of 32 consecutive days beneath zero - probably a record for a habited area. This was our last exceptionally cold month (average beneath zero). I remember our toilet freezing and a six inch icicle growing out of the cistern overflow. I reckon this is the last time I experienced a temperature beneath -10C. The cold persisted into early March. For some reason I find that February 1986 is often "the forgotten month" when one talks about extreme winters in Britain. Perhaps this is because there wasn't any widespread serious disruption due to heavy snow over a wide area, perhaps because there weren't any record-breaking low temperatures, and perhaps because the rest of the winter was unexceptional. Indeed, some parts of the country had no snow at all. Nevertheless, it was, and remains, the coldest month since January 1963.

During February 1986 snowfalls were frequent especially for the eastern side of the country. I think when one talks about the lack of snow that month, I think it was the fact that snowfalls were almost always light and often in the form of showers, and what they were not is big heavy blizzards of the type that occurred in similar easterly spells like Feb 1979, 91 etc.

[Weather-history]

5 consecutive days or more of a CET mean at or below zero being recorded in November or going into very early December. So the current run is pretty exceptional.

27th Nov-1st Dec 1978: -0.6

23rd-27th Nov 1904: -1.96

30th Nov-8th Dec 1879: -3.37

30th Nov-11th Dec 1796: -1.78

[kold weather]

Well models show at least another 3-4 days of temps likely averaging below 0C so by the 10th we are going to be decently below 0C and anything above 3C in the CET is pretty much a long shot even at this early stage. Then you've got to take into consideration that the models are blowing up th upper high in the N.Atkantic again which at the very least is likely to prevent mild conditions, but more likely its going to help to develop yet another cold northerly airflow...

Really there is no real reason why we can't go below 1C with the CET and overall no reason why we can't challenge 1981 either...

My god can't believe I just wrote that!

[West is Best]

Agreed Darren.

December could be on course to take a hammering, although we all know how things can turnaround. However, a December which starts at record-breaking cold is highly unlikely to be able to turn out significantly mild - there just isn't the solar ooomph.

We might be looking at a below freezing month for the first time in quarter of a century.

[The PIT]

I'm surprised Yesterdays came in below zero as there supposed to be some seven and eights around in the CET area. We hit 3c max and a low of -0.9c. Anyway it's going to be another week where CET takes a hammering. So unless there's a sudden heatwave for the last two weeks of this month there's going to be a real struggle to make anywhere near average.

[kold weather]

We won't even get close to average, even if the models are wrong and we don't see another major cold spell the synoptic pattern aloft in the N.Atlantic is still blocked and so we are still likely to get toppler northerlies if nothing else and given how low we are going to be by the time that set-up kicks in...thats not going to cut it...

Really anything above 2.5C is looking like a bit o a struggle at the moment...

A Freezing month is still going to require things to go more or less as the models expect and for there to be maybe another cold shot right at the end of December but its certainly looking do able at this early stage!

I thought Jan 2010 was unreal and to be fair it was very impressive but the fact December in the same year is probably going to go lower..wow...

[Polar Continental]

Drat and double drat, been so busy, forgot again, for what it is worth, -0.5c

[Optimus Prime]

I certainly wouldn't write of a CET above 3.0c just yet! Above 4.0c is extremely unlikely though. Guaranteed the 4th below average December in a row. 9th below average since 1995.

[Evening thunder]

Also realized I forgot as well, being busy and tied up with the cold spell. Think I'll refrain from guessing rather than clocking up another -50 penalty points(!) but would probably go around 0C or 1C.

I'll be watching and will find it interesting to see how low this month turns out!

[paul tall]

9th below average since 1995.

That's quite something against a general background of warming.

[kold weather]

I certainly wouldn't write of a CET above 3.0c just yet! Above 4.0c is extremely unlikely though. Guaranteed the 4th below average December in a row. 9th below average since 1995.

Nah its still a little early to write off 3C and above BUT if the models are even close then its looking a massive long shot to go above 3C...I honestly think we may well be heading towards our second severe winter month in 2010 and below 1.5C...

For example even if by magic we end up at 0C by the 15th (very unlikely to happen!) we then need to get an average of 5.6C for the last 15 days...which is of course more then do able BUT the current set-up isn't going to shift very far, even if we don't get the very cold set-up some models are desperate to bring in...

[reef]

Hadley is up to -1.3C today, yesterday was just above freezing at 0.5C, ending the run of consecutive sub-zero days at nine.

It'll be sub-zero again tomorrow though, as today's min is -5.6C.

[Weather-history]

Here is that list again but only those that recorded a CET of less than 1.0 by the 7th

1962: 0.1

1952: 0.0

1925: -0.3

1902: 0.8

1889: 0.8

1879: -3.6

1875: 0.1

1871: 0.6

1869: 0.5

1846: 0.7

1844: -0.7

1796: -1.9

1788: 0.9

1782: 0.6

Add to the fact that the last week of November was the coldest on record for the CET daily mean series, means that the period 24th November-7th December 2010 is truely exceptional.

[Radiating Dendrite]

Amazing stuff.

Tied in with slim chance of a sub 9c year.

A trend certainly seems to be emerging, the word downwards springs to mind.

[North-Easterly Blast]

Here is that list again but only those that recorded a CET of less than 1.0 by the 7th

1962: 0.1

1952: 0.0

1925: -0.3

1902: 0.8

1889: 0.8

1879: -3.6

1875: 0.1

1871: 0.6

1869: 0.5

1846: 0.7

1844: -0.7

1796: -1.9

1788: 0.9

1782: 0.6

Add to the fact that the last week of November was the coldest on record for the CET daily mean series, means that the period 24th November-7th December 2010 is truely exceptional.

We could be looking at one of the coldest first halves of December ever. From my knowledge, the coldest first halves of December (below 2.0*C) of the 1900s are 1916 (1.2), 1933 (1.1), 1950 (1.6), 1952 (1.7), 1981 (0.. Any other cold or colder first halves of December, Kevin?

[AderynCoch]

It'll be sub-zero again tomorrow though, as today's min is -5.6C.

Today's max looks very low, with -3s and -4s widely in the CET zone. Another -4C daily mean on the cards?

[summer blizzard]

Mr Data, could you post the top 10 coldest for the 1st-10th period, 1st-15th and 1st-20th, so that we can moniter where we stand.

All i can say right now is wow, what an amazing cold spell and what an amazing model output for December. Right now the models are in agreement out to day 10, with generally settled weather but cold, before lining up a northerly hit at day 9-10.

My take on the CET is that from our current -1.3C, we will most likely see a rise to the 10th, but only to near 0C, the 10th-15th sees what looks like a generally sunny but dry setup from the east, and i would expect some spectacular minima over western England/Wales (the same setup gave -18C in Wales last week), thus i think that by the 15th, we will be below -1C again, and with the 15th-20th looking like we will see a direct northerly, i cannot see any upward movement.

I really cannot believe this conclusion, but i truly believe the 1st-20th, will average below -1.5C! That would be over 6C below average!!!!

[BornFromTheVoid]

Going by the 12z GFS, looks to me like we'll be at:

-1.8C to the 6th,

-2.2C to the 8th,

-1.6C to the 10th,

-0.8C to the 12th,

-0.6C to the 14th.

[Weather-history]

We could be looking at one of the coldest first halves of December ever. From my knowledge, the coldest first halves of December (below 2.0*C) of the 1900s are 1916 (1.2), 1933 (1.1), 1950 (1.6), 1952 (1.7), 1981 (0.. Any other cold or colder first halves of December, Kevin?

1976 (1.9)

[Stu_London]

Hadley is up to -1.3C today, yesterday was just above freezing at 0.5C, ending the run of consecutive sub-zero days at nine.

It'll be sub-zero again tomorrow though, as today's min is -5.6C.

Be worth checking that figure again when it is confirmed.

I've seen a day lose half a degree before now

[damianslaw]

Carol Kirkwood on the One Show made some quite startling statements today, she said we are seeing the coldest spell of weather since Jan 1987 and before then we have to go back to 1740 - I'm not sure what script she was reading from but she seems to have forgotton Jan 1963 and 1940 and Feb 1929 and winter 1894/95 and infamous winter 1813/1814 - I'm sure there have been colder spells in between 1740 and 1987 compared to now- but I could be wrong.

How does the last 10 days compare with the first 10 days of Jan this year?

[paul tall]

She will have been instructed by The Climate Change Industry to really ram home just how cold the weather is, even if slightly stretching the truth.

Now they realise that cold spells are not a thing of the past as they were stating a while back, they need to use cold spells to their advantage to keep The Climate Change Industry running - coldest spell for 300 years, and oh by the way you can expect more regular extremes like this as THE CLIMATE CHANGES (cheque please).

[kold weather]

Not going to be alot in it Damianslaw, they probably will come out with very similar values...

That being said tomorrow could well end up even more impressive then today, mins already widely into the -8/9/10C range and we'll probably shave another couple of degrees off before sunrise so don't be surprised if we get a min of -7C or lower tomorrow in the CET estimate, no reason if thats the case why we can't get close to -4C tomorrow (well today really!)

Models are slowly weakening the so called 'milder' spell and indeed now the models show what could still be described as a cold set-up for the weekend, though certainly not on the same level as this current week....should still easily be below 0C by Mid month and with a possible new cold shot coming down we really may well have the risk of a sub 0C month...

That being said sub 2C is looking more likely and sub 3C is looking just about odds on...but in theory still more then makeable under a certain set-up if the models are wrong about the cold...now anything above 3.5C is looking unlikely...so looks like we are going to have another December well below average...the 3rd in a row!