January CET

[Snowyowl9]

Last January was a very cold start with an ice day here the same as this year not quite as cold though.

3 ice days last January here 3rd and 6th which was bitter same as the 1st.

[Snowly does it]

Well the first days worth of data has come in now.

1st of Jan came out at -0.3C so we start off 2010 with an ice day. Last nights mins came in at -2.8C though todays maxes may be a little higher around 3-4C so probably a slightly above 0C day tomorrow, though today and tomorrow look like being the mildest day in the next 10-12 days more then likely and they will still be well below average anyway.

I'll make a stats update with regards to other Jans later on today.

Some quite surprising Maxima around today - some 5s on display in the CET area so could be a 1.5 or so today for the CET zone. Should be back under zero fairly soon though!

[kold weather]

Yep the Irish sea seems to have helped the temps get a little higher, as well as a stronger troughthen expected which resulted in probably slightly milder uppers then the models were expecting, seems to have made the difference.

Mins last night were -2.8C so even if we were to get a 5C max I'd have though about 1C is the likely mark...still way below average but probably the mildest day of the cold spell I suspect.

[Weather-history]

Also worth noting that since the 11th we have averaged 1.8C

That was based on provisional figures, with the updated figures it turned out to be 1.4C and this made it the coldest 11th-31st December period since 1981 even surpassing 1995

11th December -1st January CET: 1.3C

[kold weather]

Yep I have had to alter all my data because of that, but yep dropping away nicely, as you say Mr.Data down to 1.34 so certainly a very impressive cold spell...

Also that alteration makes it much more possible to get a sub 0C rolling 20 day CET as well...a 30 day period below 1C also looking more then possible...down to 2.85C and going to see some very large drops as we get the ice days come in next week and lose the very mild early December days.

[Stu_London]

This post is just for fun but,

should the 12z verify then we would be at about -1.6C at the end of the higher resolution (10th) and back to -1.2C by the end of run (18th).

My concern is that the minimas might be underdone under slack flows and snow cover so we could actually see a bit lower than that (my figures assume a lowest minimum of -5C)

If we were at -1.2C by the 18th then to avoid an ice month we would need 1.6C from the 19th.

To get to 1C we would need 3.9C from the 19th

to get to 2C we would need 6.4C from the 19th

To get to 3C we would need 8.8C from the 19th

There is some talk of a reload in the model discussion - personally I think the best chance of an ice month would be a for hp to sink over us from scandinavia for the final 3rd of the month.

[kold weather]

Yep Stu quite an insane run from the 12z!

Also as I said before elsewhere, worth watching just how low it goes later this week because we have a real shot at the coldest first 10 days in the last 100 years, since most of the legandary Jan's tended not to get going till after the 10th....

I also agree with you Stu in the fact that the mins could well be underdone if we get the set-up and the snowfalls as progged, the low resolution part of the run very likely will under-estimate the mins.

The fact we are even talking about an ice month shows just how mental the models are at the moment!

Anything above 3C right now looking very unlikely given the models are now extending the cold spell out to the 15th broadly...

[damianslaw]

I think maxes in the CET zone today were roughly between the 3-5 mark. It was interesting watching my car themometer yoyo between 1 and 5 degrees as I travelled on a rather roundabout route from Ipswich to Kendal through the east midlands and west yorkshire. It hit 4 degrees close to Leicester then fell to 1 degree near Keighley as I hit the high ground.

Today certainly looks like being the mildest day of the upcoming very cold spell.

[kold weather]

Yesterday came out surprisingly cold at 0.5C which takes the CET upto 0.1C for the first 2 days...

Tuesday onwards should see some very cold days indeed, with even the Beeb going for ice days in the heart of London and therefore probably will see several days down to about -3/4/5C I'd imagine...

Therefore even if the set-up does breakdown before the 15th as hinted at by some of the models we should still be below 0C...

[kold weather]

Here is the updated CET tracker:

Data from 1-2nd:

Jan 1979--- -3.25c (-0.4c)

Jan 1997--- -2.2c (2.5c)

Jan 1868--- -1.4c (3.9c)

Jan 1940--- -1.3c (-1.4c)

Jan 1963--- -0.8c (-2.1c)

Jan 2009--- 0.1c (3.0c)

Jan 2010--- 0.1c

Jan 1894--- 0.95c (3.2c)

Jan 1985--- 3.05c (0.8c)

So as we can see Jan 10 is at the same point as 09 is at the moment, I'd imagine by the 10th Jan 2010 will be very close to the top of that list...

[Snowly does it]

Yesterday came out surprisingly cold at 0.5C which takes the CET upto 0.1C for the first 2 days...

Tuesday onwards should see some very cold days indeed, with even the Beeb going for ice days in the heart of London and therefore probably will see several days down to about -3/4/5C I'd imagine...

Therefore even if the set-up does breakdown before the 15th as hinted at by some of the models we should still be below 0C...

Kold, where are you getting the updates from? The site doesn;t seem to be showing anything for 2010 when I look

[Nick L]

Yeah, I can't find anything either, poor show from the Met Office!

The CET will take a battering tonight, -5c here already and still falling.

[kold weather]

There you go:

http://hadobs.metoffice.com/hadcet/cet_mean_est_2010

Worth noting that we have a real shot at getting the coldest first 10 days of Jan since 1900...we only need to get down to -0.9C and a few bitterly cold days would take us some way to where we need to go to reach that target...

I think that would go to show just how exceptional this cold spell really could be, the coldest for the time of year since 1894 possibly?

[Weather-history]

There you go:

http://hadobs.metoffice.com/hadcet/cet_mean_est_2010

Worth noting that we have a real shot at getting the coldest first 10 days of Jan since 1900...we only need to get down to -0.9C and a few bitterly cold days would take us some way to where we need to go to reach that target...

I think that would go to show just how exceptional this cold spell really could be, the coldest for the time of year since 1894 possibly?

Here's a list I posted on Ukweatherworld earlier today

Sub-zero 1st-10th January periods for the CET

1774: -1.1C

1777: -1.5C

1780: -0.6C

1784: -0.7C

1789: -2.2C

1794: -0.1C

1795: -2.6C

1799: -0.1C

1802: -0.3C

1811: -1.8C

1814: -3.0C

1820: -2.5C

1841: -2.0C

1842: -0.3C

1850: -0.1C

1861: -1.0C

1864: -2.1C

1868: -0.1C

1879: -1.2C

1887: -0.5C

1891: -1.1C

1893: -2.0C

1894: -1.8C

1941: -0.8C

1963: -0.6C

1979: -0.5C

1997: -0.6C

2009: -0.4C

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

That would really put this cold spell into perspective if the first 10 days of Jan were to be the coldest in 100 years!

Edited January 3, 2010 by RAIN RAIN RAIN

[Snowly does it]

There you go:

http://hadobs.metoffice.com/hadcet/cet_mean_est_2010

thanks!

[cheeky_monkey]

I think maxes in the CET zone today were roughly between the 3-5 mark. It was interesting watching my car themometer yoyo between 1 and 5 degrees as I travelled on a rather roundabout route from Ipswich to Kendal through the east midlands and west yorkshire. It hit 4 degrees close to Leicester then fell to 1 degree near Keighley as I hit the high ground.

Today certainly looks like being the mildest day of the upcoming very cold spell.

dont take car thermometers as a true guide... temps are generally 1-1.5c colder than shown during cold spells..due to heat given of by the road the ambient engine temperature and exhausts.

[kold weather]

Maxes today look to have been between 0-2C, so pretty certain to get a CET ice day mean today.

Tomorrow could well come out as a very cold day indeed, mins already lower then that last night and I'd imagine we are looking at a CET min of -5/6C and if thats the case then a day between -2/3C looking odds on and that will really help to drag the CET down...as well as increasing our chances of getting that target of the coldest start for over a 100 years.

[damianslaw]

dont take car thermometers as a true guide... temps are generally 1-1.5c colder than shown during cold spells..due to heat given of by the road the ambient engine temperature and exhausts.

Thanks for the post, yes I always have questioned the true accuracy of car thermometers. There have been many mornings recently when it has clearly been at 0 degrees or below yet the thermometer seems to have been stuck on 1 or 2 degrees.

If your downward correction is right then we will have only recorded a max of -1 degree here, the thermometer never getting above 0 degrees as I travelled through the southern lakes this afternoon.

[kold weather]

The 18z suggests we will still be close to 0C by the 20th, if thats the case then a sub 3C will be nailed on...

I think at the moment anyone who went above 3C is going to be quite some way out....

[Guest]

There is still the rest of the month to go and in Jan 1963 there was much more snow lying in the SE so I remain to be convinced.

[Roger J Smith]

I would not be surprised to see days in the -5 to -3 C range on the daily CET later this week, and I would be really surprised if the monthly average made it above 1.0 before the 20th if the models are not totally wrong about future evolution ... and I think there will be reasonable snow cover after this week too. Wouldn't it be astounding if the month could remain below zero? I think we're seeing that it's only a question of duration, not intensity.

Most of the really cold months seemed to produce a week to ten days in the -6 to -8 C range, and I don't see that as totally beyond reach either if snow cover is established followed by high pressure.

[Weather-history]

A pretty good chance of it being the coldest first half to winter (1st December-14th January) since 1981-82

1st Dec 1996-14th Jan 1997 CET: 2.3C

1st Dec 1981-14th Jan 1982 CET: 0.2C

[kold weather]

I think its quite possible Roger, I think given the synoptics progged something below 2C now looking very probable, a slack SE flow with snowcover present will no doubt be able to give those -5/6/7C readings that we see at times in those severe months you mention...

Yesterday came in at -0.8C so we are now at -0.2C for the first 3 days.

Last night mins ame in at -6.1C...therefore todays maxes seem somewhat more surpressed then was forecast...I'd imagine the CET will get an ice day therefore something around -3C seems quite probable which will send the CET down quite some way and get us on our way towards the needed -0.9C...

[Nick L]

I think its quite possible Roger, I think given the synoptics progged something below 2C now looking very probable, a slack SE flow with snowcover present will no doubt be able to give those -5/6/7C readings that we see at times in those severe months you mention...

Yesterday came in at -0.8C so we are now at -0.2C for the first 3 days.

Last night mins ame in at -6.1C...therefore todays maxes seem somewhat more surpressed then was forecast...I'd imagine the CET will get an ice day therefore something around -3C seems quite probable which will send the CET down quite some way and get us on our way towards the needed -0.9C...

Still -3c here, so my max will be roughly -2c, possibly -1.5c. Either way, it's bitterly cold.

Makes a nice change though to be looking at a potentially nailed on sub-3c month!

Edited January 4, 2010 by nick2702