December CET

[Cymro]

What I dont understand is why we trust these old historic figures. What's to say that they are accurate? Where were they recorded because they certainly can't be classed as CET (Central England Temperatures) Because the measuring stations and what have you have changed. I would say that we should only really compare with reliable records that are comparable with the ones we have now.

[Stu_London]

Just to clear this up, because I'm a little unsure. Are the above 'hits' you've researched all for the CET mean being below zero over this specific three day period? And if so, does this mean that a CET 'ice day' only constitutes the mean being below zero and not the the CET max being sub-zero too?

Looking at the data from 1882 where we have maximums and minimums for each days, there hasnt been a single year where both the minimum and maximum have been below 0c for each of the 3 days (1962 came close but boxing day had a max of 1C)

A reasonable chance that 2010 will set a record in this respect

What I dont understand is why we trust these old historic figures. What's to say that they are accurate? Where were they recorded because they certainly can't be classed as CET (Central England Temperatures) Because the measuring stations and what have you have changed. I would say that we should only really compare with reliable records that are comparable with the ones we have now.

I agree there is some doubt.

However, they give us an idea as to what periods were cold and what periods were not.

The key period for me is 1785-1830 (encompassing the Dalton Minimum period). Suggests that grand minimums not only had colder winters but longer winters also.

If we are at the start of a comparable minimum, then 2009 and 2010 fit that profile quite nicely, although they are no where near providing proof of a new trend.

[Optimus Prime]

Ok fair enough the ECM and UKMO would blast the CET downward. Don't have a clue where the CET will end up. Possibly as tropical :sarcasm: as 1.5c but possibly as frozen as -2.0c. Of cvourse I'd love it to come in as low as -2.0c just for mauling the previous record setters. I'm just glad I was the one hosting this thread as it's legendary.

[Beazle]

Thank you TWS.

I have real concerns about the Met Offices's CET figures being "official" for precisely the same reasons previously given by Eden. I much prefer and trust Eden as a more accurate continuation of Manley despite Parker's work. For me at least, Eden's current figure of 0.9 will do.

[West is Best]

I know this isn't in the CET zone as such but Altnaharra has not risen above -18C all day and is -19C at 15h00. If cloud doesn't roll in it's going to be pushing down in the -20's tonight. I doubt it will reach the British record of -27.2C but it may not be a million miles away.

[trickydicky]

I know this isn't in the CET zone as such but Altnaharra has not risen above -18C all day and is -19C at 15h00. If cloud doesn't roll in it's going to be pushing down in the -20's tonight. I doubt it will reach the British record of -27.2C but it may not be a million miles away.

The maximum there today of -17.5, if comfimed, will be the lowest ever maximum recorded, beating the -15.9 at Fyvie Castle on 29th December 1995.

[Isolated Frost]

I predict:

-0.4C to the 20th

-0.6C to the 21st

-0.7C to the 22nd

-0.7C to the 23rd

-0.8C to the 24th

-0.9C to the 25th

-0.8C to the 26th

-0.7C to the 27th

-0.5C to the 28th

-0.5C to the 29th

-0.4C to the 30th

-0.2C to the 31st

-0.4C after adjustments

Woop! I've got the first two right, I might get the whole thing.

Guesswork >> Ensembles.

[Optimus Prime]

Nope lowest ever maximum was -19.1c on 10th January 1982 at Braemar. Wasn't an overly cold month though.

[johnholmes]

An Ice Day is when the maximum temperature fails to reach 0C, in a 24 hour period from 09z-09z.

From Met O Glossary

CET mean is just what the label says, CET MEAN, sum of max+min divided by 2

So you can have two different results depending on which you are using. The first is the official one but if you clearly state what you are using as the base line then everyone knows what is meant.

[kold weather]

Ok fair enough the ECM and UKMO would blast the CET downward. Don't have a clue where the CET will end up. Possibly as tropical :sarcasm: as 1.5c but possibly as frozen as -2.0c. Of cvourse I'd love it to come in as low as -2.0c just for mauling the previous record setters. I'm just glad I was the one hosting this thread as it's legendary.

Even 1.5C is now totally out of the question, even one of the mildest last weeks would not get us upto 1.5C from where we likely be by Boxing day....

[trickydicky]

Nope lowest ever maximum was -19.1c on 10th January 1982 at Braemar. Wasn't an overly cold month though.

See, thats what i thought but: http://www.metoffice.gov.uk/climate/uk/extremes/monthly_temperature_country.html#lowest_daily_maximum_scotland

[Optimus Prime]

See, thats what i thought but: http://www.metoffice...aximum_scotland

In that case the records been broken. Take a look at Northern Ireland Lowest Daily Maximum. Will be 4/12 cold records broken since 2000 once the've updated that grid. Only 1 for England, October 2008.

[West is Best]

So to be clear, we have just witnessed the coldest day ever recorded in the United Kingdom?! That's right then? Goodness me.

That certainly seems to have been the previous UK record: -15.9C.

So if -17.5C is confirmed that smashes it.

Edited December 22, 2010 by West was Best

[Mark Bayley]

I'm guessing the UKMO would lead to the coldest December on record! To me thats more important than the snow. Having the chance to say I lived through the coldest December on record

[kold weather]

UKMO probably is colder then Feb 86 as well so that would probably give a sub -1C .

12z GFS is still going for a breakdown but as West said yesterday its still putting it back, now doesn't get much less cold till the 29th (the 28th is still reasonably below average!) and even after the 28th the GFS is much less mild then the 06z run...

Probably something like -0.5C if the 12z comes off...

[Thundersquall]

Wow, minus 0.27C! When was the last time the CET for December was negative degrees C?

I predict this temperature to rise a little after Boxing Day, so am going to plump for bang on 0.0C.

[West is Best]

Altnaharra -19.9C at 17h00.

Is the UK lowest record under threat? So much depends on cloud cover, wind etc. The slightest changes and it will lift. But if the conditions remain static it could surely get to -25C?

[Helvellyn]

am i right in thinking altnaharra is a relatively new station?

[Cymro]

If things carry out as planned I suspect Altnaharra could generate a new british record. To second that here it is currently -7!! My record was last kanuary at -18. And it didnt get to -5 even till 8pm that night.

[Supercell]

Altnaharra -19.9C at 17h00.

Is the UK lowest record under threat? So much depends on cloud cover, wind etc. The slightest changes and it will lift. But if the conditions remain static it could surely get to -25C?

Unfortauntely the fog has set in and that's warmed the temp to -18.6C at 18:00.

[paul tall]

See, thats what i thought but: http://www.metoffice.gov.uk/climate/uk/extremes/monthly_temperature_country.html#lowest_daily_maximum_scotland

The Met Office are wrong.

Everybody knows the -19.1 at Braemar is the lowest max.

[The PIT]

Didn't realise Scotland was in the CET zone. Oh it isn't so dunno what it's doing in the CET thread.

With the warm up already sneaking in it's going to be a struggle to too record the coldest ever December. Need some quiet clear still nights and I'm not sure those on the cards. Will the high be a cold clear one or cloudy one with night temps close to day temps.

[Stu_London]

Didn't realise Scotland was in the CET zone. Oh it isn't so dunno what it's doing in the CET thread.

With the warm up already sneaking in it's going to be a struggle to too record the coldest ever December. Need some quiet clear still nights and I'm not sure those on the cards. Will the high be a cold clear one or cloudy one with night temps close to day temps.

12z GFS would bring an outcome of -0.6C for the CET before adjustments. Most of this is in the high resolution part of the run now.

10% chance of something above 0C

50% chance of the record going

[Cymro]

Didn't realise Scotland was in the CET zone. Oh it isn't so dunno what it's doing in the CET thread.

With the warm up already sneaking in it's going to be a struggle to too record the coldest ever December. Need some quiet clear still nights and I'm not sure those on the cards. Will the high be a cold clear one or cloudy one with night temps close to day temps.

Um the CET thread is used generally to talk about the CET and records across the UK regardless of the observation stations! How rude to Scotland (with some exceptionally low temperatures). In that case would you argue that any Northern Ireland, Northern England, Scotland, Or Wales record low temperature/ general average would not be welcomed in this thread?

Why not just limit to the people of Central England because thats what the CET means!.

[Optimus Prime]

Didn't realise Scotland was in the CET zone. Oh it isn't so dunno what it's doing in the CET thread.

Didn't realise, as a human being you were so perfect. Apologies.