January CET

[North-Easterly Blast]

I don't think of late Nov/early Dec 2008 as a good example of cold zonality in the January 1984/December 1993/March 1995 sort of way, the cold was delivered primarily by a succession of northerly outbreaks (and I think the same could be said of 5-15 February 2009 which, although featuring a strong Atlantic influence, had airmasses mainly coming down from the north). The nearest approach was probably the second half of January 2009 which delivered a fair amount of snow to upland parts of the west, including SW England, though falls and accumulations of snow at low levels were very limited. I don't agree with the notion that late Nov/early Dec 2008 didn't deliver as much snow as December 1993 and March 1995- I thought the amounts and geographical distribution were quite similar to the December 1993 case in particular.

You need to remember though that the period 12-26 January 1984 was the "cold zonality" equivalent of the easterly of 11-14 January 1987- i.e. probably the most extreme case of the entire twentieth century, and most of the cold zonal weather of the past has given only short-lived snowfalls to low ground. The February 1970 instance was bolstered by a subsequent spell of northerlies around midmonth which locked in the cold air.

To be honest I would quite fancy a climate where temperatures and precipitation were inversely related all year round with a lot of cold zonality and with anticyclonic spells often being mild and sunny, but both of those have always been the exception rather than the rule in UK winters. Interestingly that sort of consistent inverse relationship does seem to hold in the east and south of the South Island of New Zealand but their equivalent of cold zonality only tends to bring snow to higher ground due to their lower latitude.

I really do think also that the period 25th Nov - 9th Dec 2010, for so early in the winter season, was equally as unprecedented as seeing an easterly in the mid-winter period like 11th - 14th Jan 1987, or seeing a prolonged freeze up without a break like the one from Dec 23rd 1962 to March 3rd 1963. The extreme cold seen from Nov 25th to Dec 9th 2010 was definitely one of, if not a record breaker of a cold spell so early in the winter season. If an extreme cold spell at equal levels to this was to occur in January or February then it wouldn't have been quite so extreme.

Surely the period from Nov 25th to Dec 9th 2010 is the coldest two week spell ever to occur in late November and during the first half of December. Quite possibly I would have thought that the period 25th Nov to 24th Dec 2010 is the coldest pre-Christmas month on record. If this can happen then why is it not possible for the UK to witness a winter comparable to 1962-63 where deep cold sets in just before Christmas, never to relent or loose its grip until early March? Given the extremity of the early season cold this winter also why can cold zonality not return? Even in the past it has been unheard of to get cold zonality lasting for a whole month. Even in the first half of Jan 1984 the zonal flow was really quite mild for England at least with a few northerly topplers. It was around the 13th / 14th Jan 1984 that the famous event of cold zonality developed and lasted for two weeks, giving frequent and heavy snowfall to most of the country, and snow lay in many areas for a week or more (that was with very little northern blocking in sight and a positive NAO / AO).

Re the Jan 1987 easterly. I think that the Feb 1991 easterly was possibly one of the most extreme cases of the quantity, how heavy and widespread the snowfall was. It was a little less extreme than the Jan 87 easterly for coldness, but the Feb 91 easterly brought overall, more heavy blizzards to a wider area of the UK than in Jan 87.

Re - cold zonality: February 1970 saw a good deal of cold zonality with little in the way of northern blocking although there was a northerly spell around mid-month. That month however did deliver reasonable snowfall from a cold zonal polar maritime setup. You have not made any points to February 1968, that month saw fairly widespread snowfall from cold zonality around the 6th / 7th.

To get a zonal flow of the cold variety you need the Atlantic depressions tracking NW-SE, even with pressure low to the N / NW, with the Azores High well out west and pressure mostly low over Biscay / Europe. In the last 20 years or so, what we have seen is for the track of zonal flows to be more SW-NE, for pressure to be higher over Biscay / Europe, and more low pressure is always moving in this track cutting off the polar maritime feed between passing lows. If northern blocking more typical of the pre 1988 era can make its appearance again in the last two years, then why can cold zonality of this type described happen again?

Suspect we will see the peak CET value for January occuring on Sunday, thereafter a slow decline becoming more marked during the latter part of the month. I am still expecting a month either very near average or a bit below.

This week does indeed look a very mild one for January, but nothing unusual, in fcat in recent January's weeks like this were quite normal, 2005, 2007, 2008 and even the mid period of 2009 saw very mild January weeks. Indeed it is a rare feat not to see at least one mild spell of weather in Jan lasting min of 5 days. Even last Jan we saw a relatively mild spell in the second half of the month.

The upcoming spell of weather reminds me a little of the infamous wet spell in Nov 2009, thank goodness we have had a dry spell of weather, otherwise plenty of severe flooding would be on the cards.

We may have seen milder weather during the second half of last Jan, but it was generally not much milder than average and certainly nothing like the mild spell coming up in these next few days.

[Lettucing Gutted]

The CET is going to race upwards in the next 7 days, looking very mild indeed with some days probably averaging close to 10C, probably be upto 5.5-6C by the 20th. Hints of something decently colder developing beyond then but the damage will likely be done by then and its going to require a pretty decent cold spell to end up much below average.

IMO between 4-5C looks the most likely call...

Sod's law. I punt below average and I end up too low! By the way it looks like December 2010-January 2011 will see the biggest December-January increase on record perhaps even beating the December 1673-January 1674 increase from 0.5C upto 5C.

Edited January 12, 2011 by Craig Evans

[paul tall]

Looking at those 1981-2010 averages it is worth pointing out that there was no unusually severe January in that period (last such were Jan 1979 and Jan 1963) while we had December 2010 and February 1986 to pull down the average for both those months. Obviously we are talking tiny fractions here but you'd expect December to be rather more clearly the mildest winter month and for February to be very slightly less cold than January.

When does the new reference period come into operation?

Never.

The Met Office will continue to use the 61-90 averages, just as some other countries irritatingly still do, because it was a cold period. Suits the climate change industry, know what I mean?

[North-Easterly Blast]

Looking at records, to look at Decembers similar to Dec 2010, there were 15 "very cold" Decembers in the CET record (excluding Dec 2010) that recorded a CET of less than 1*C. Whilst this may not be quite as low as Dec 2010 all Decembers below this figure have been very similar to Dec 2010. Out of all these 15 Decembers, only one of the following Januarys recorded a CET above 3.5*C (which was 1875 at 6.4*C), and the average CET of all the 15 Januarys that followed a very cold (sub 1*C) December is 2.0*C. So the odds of getting a mild January after a very cold December appear to be low according to what history tells us. 1874-1875 was very much topsy turvy, after the very cold Dec and very mild Jan, Feb was a much colder month again at 2.3*C.

[kold weather]

Still not an easy call as to what will happen this month, I think unless something gets pulled out of the bag so to speak in the last 7-10 days of the month the range we are IMO highly likely to be looking at is 3-5.5C...think anything outside of that range is unlikely IMO...

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

Sod's law. I punt below average and I end up too low!

If you had done your usual 8C punt you would have been closer than most!

[Weather-history]

Sod's law. I punt below average and I end up too low! By the way it looks like December 2010-January 2011 will see the biggest December-January increase on record perhaps even beating the December 1673-January 1674 increase from 0.5C upto 5C.

December 1874 to January 1875 is the record.

An increase of 6.6C

It would require January 2011 to have a CET of 6.0C to beat it.

[North-Easterly Blast]

December 1874 to January 1875 is the record.

An increase of 6.6C

It would require January 2011 to have a CET of 6.0C to beat it.

This is still possible given the output of the models at present; although there are some signs of high pressure building in over the UK next week there seems little prospect of any change in low heights to the north of the UK, and there doesen't appear to be a great deal of sign in the models to say that we are not in a mild zonal Bartlett Jan 2008 pattern. However, it is rare for January to be mild overall after a very cold to exceptionally cold December. Out of all the 15 Decembers in the records that had a CET of less than 1*C, history tells us that in fact Jan 1875 is the only January that even got above 3.5*C following a very cold December (CET less than 1*C). In fact, including Jan 1875, the average CET of the 15 Januarys that followed a sub 1*C December is 2.0*C. So it will certainly be disappointing if January is a mild month overall given the December that we have had, and will make quite possibly Winter 2010-11 join the list of pear shaped winters like 1996-97, 1944-45 etc, and definitely if February also isn't up to much. If the rest of the winter delivers nothing special, then a large proportion of winter 2010-11 will still have been rubbish.

I certainly wonder if we can ever see a winter again that has a decently mild December followed by a much colder January and February, which more so than anything else, is THE pattern that has been MOST UNHEARD OF in the post 1988 era. Winters 1985-86 and 1984-85 were good examples, as was 1986-87, and further back 1954-55 was the most perfect example (a milder December than any post 1988, and a pretty good Jan and Feb). 1953-54 was another example, 1955-56 was also pretty similar too. Winter 1978-79 also bore some similarity to this to a lesser degree; Dec 1978 (3.9) (not that mild, but still the mildest December in the sub 2*C winters in the 1900s), was still followed by a considerably colder January and February.

Edited January 13, 2011 by North-Easterly Blast

[Kentish Man]

Hadley is on 3.7C today (Jan 1 - 12)

Looking at that 1874/75 example it was certainly an odd winter. After a chilly 5.6C in Nov, a severe - 0.2C in Dec and a very mild 6.4C in Jan the CET fell back to only 2.2C in Feb and still only 5.1C in March. There can't be many years where January is the mildest of the five from November to March.

[BornFromTheVoid]

Going by the GFS 12z we'll be at,

4.2C to the 13th,

4.9C to the 15th,

5.4C to the 17th,

5.1C to the 19th,

4.9C to the 20th.

[Optimus Prime]

I certainly wonder if we can ever see a winter again that has a decently mild December followed by a much colder January and February,

Oh please no more of this superstitious stuff please. I think it's rather silly to think up something like that.

[ZONE 51]

3.8c 0-: the 0.8c i think is a bit low! Bit late now though..

[Weather-history]

.

I certainly wonder if we can ever see a winter again that has a decently mild December followed by a much colder January and February,.

Have no lessons be learnt? You can't strait-jacket the weather.

We have the "will we ever see a sub 3C CET month?" We saw 3 in one year.

"Will we ever see a sub-zero CET month again?" Yes we did.

Now logic tells me that a sub-zero CET month should be harder to achieve than a mild December followed by a colder January and February. I fail to see why you can't extrapolate this logic?

I think the problem here is, is that its never enough for some people. Wasn't it enough that we lived through the coldest December for over 100 years that no one alive has experienced? The most severe pre-Christmas 30 day cold spell for probably over 300 years?

Look at 1985-86, that had a very mild December and very cold February, what difference does it make where it comes as long as it does comes if you want really cold weather. To me, it made it very festive and fitting with the run-up to Christmas being cold and snow on the ground.

I think its absolutely ridiculous for people to expect continuous severe cold ala 1962-63 style.

Here are winter examples of two very cold months with a much milder third month

1870-71

Dec: 0.6

Jan: 0.5

Feb: 6.1

1879-80

Dec: 0.7

Jan: 0.9

Feb: 5.8

Edited January 14, 2011 by Mr_Data

[North-Easterly Blast]

Have no lessons be learnt? You can't strait-jacket the weather.

We have the "will we ever see a sub 3C CET month?" We saw 3 in one year.

"Will we ever see a sub-zero CET month again?" Yes we did.

Now logic tells me that a sub-zero CET month should be harder to achieve than a mild December followed by a colder January and February. I fail to see why you can't extrapolate this logic?

I think the problem here is, is that its never enough for some people. Wasn't it enough that we lived through the coldest December for over 100 years that no one alive has experienced? The most severe pre-Christmas 30 day cold spell for probably over 300 years?

Look at 1985-86, that had a very mild December and very cold February, what difference does it make where it comes as long as it does comes if you want really cold weather. To me, it made it very festive and fitting with the run-up to Christmas being cold and snow on the ground.

I think its absolutely ridiculous for people to expect continuous severe cold ala 1962-63 style.

Here are winter examples of two very cold months with a much milder third month

1870-71

Dec: 0.6

Jan: 0.5

Feb: 6.1

1879-80

Dec: 0.7

Jan: 0.9

Feb: 5.8

1985-86 was not devoid of cold until late January. Yes it was very mild up to Christmas 1985, but then there was some cold weather in the last week of December that continued more or less until around the 10th of January 1986, and there was a reasonable snow event further north in the first part of Jan; there was then a milder spell again through mid-January, before it turned cold again around the 25th / 26th Jan, which went on to last into early March - so we we had already seen some cold and snow by this present point in the 1985-86 winter.

I can also point out that Dec 1985 looked on course to rival the mildest December ever (the CET was 8.1 to the 24th), but in the last week the cold was intense enough to shave 1.8*C off the CET, and in the end the month didn't even make the 20 warmest Decembers ever.

At least in the above two years (1870-71, 1879-80) the cold lasted for most of January too, and it was only February that was a poor month - in other words a bit like the summer of 2010 where June and July were mainly warm, and it was only August that turned cooler, so two thirds of summer 2010 were warm overall rather than one third.

The point that I am making is that if the scenario was to arise of the whole of January and February this winter remaining largely mild and mostly snowless then winter would have effectively ended on December 27th and two thirds of this winter would still have been poor. I think that pre Christmas there is more to life in that you are busy preparing for Christmas / shopping, writing Xmas cards etc, and if we have to go from Christmas all the way through to early March without a sniff of cold I find it is a painfully slow two months or more to get through.

Personally my first choice would be to have cold spells spread throughout the winter period (rather than concentrated at one end or in one quarter or third) then there is always something exciting to watch for from early December to early March even if it is not cold all the time - last year was pretty good - there was some cold weather close to the festive period (it started a week before), and severe cold in the first half of January; although the intense cold never really returned after mid January, Feb 2010 still turned out to be colder than average and still had one or two snow moments. 1995-96 was reasonable too - there was some cold from around the 5th Dec which lasted on and off for most of the month, and after a mild first three weeks to Jan, there was another cold spell in the last third of Jan lasting into the early part of Feb; that month then remained on the cold side.

My second choice would be to have a month long cold spell similar to pre Christmas this year from around mid-January to mid-February, even if the rest of the winter is average, as it helps to fill up tthe wo months after you have had Xmas before spring is on its way. Prior to Christmas as I mentioned before there is always Christmas to look forward to, and once Christmas is gone there is nothing to do in life until spring and March / April arrives, and I find it unthinkable to have winter ending when Christmas is hardly out of the way and to have to get through two long months of mild dross before spring is in the air.

Edited January 14, 2011 by North-Easterly Blast

[Nick B]

1985-86 was not devoid of cold until late January. Yes it was very mild up to Christmas 1985, but then there was some cold weather in the last week of December that continued more or less until around the 10th of January 1986, and there was a reasonable snow event further north in the first part of Jan; there was then a milder spell again through mid-January, before it turned cold again around the 25th / 26th Jan, which went on to last into early March - so we we had already seen some cold and snow by this present point in the 1985-86 winter.

I can also point out that Dec 1985 looked on course to rival the mildest December ever (the CET was 8.1 to the 24th), but in the last week the cold was intense enough to shave 1.8*C off the CET, and in the end the month didn't even make the 20 warmest Decembers ever.

At least in the above two years (1870-71, 1879-80) the cold lasted for most of January too, and it was only February that was a poor month - in other words a bit like the summer of 2010 where June and July were mainly warm, and it was only August that turned cooler, so two thirds of summer 2010 were warm overall rather than one third.

The point that I am making is that if the scenario was to arise of the whole of January and February this winter remaining largely mild and mostly snowless then winter would have effectively ended on December 27th and two thirds of this winter would still have been poor. I think that pre Christmas there is more to life in that you are busy preparing for Christmas / shopping, writing Xmas cards etc, and if we have to go from Christmas all the way through to early March without a sniff of cold I find it is a painfully slow two months or more to get through.

Personally my first choice would be to have cold spells spread throughout the winter period (rather than concentrated at one end or in one quarter or third) then there is always something exciting to watch for from early December to early March even if it is not cold all the time - last year was pretty good - there was some cold weather close to the festive period (it started a week before), and severe cold in the first half of January; although the intense cold never really returned after mid January, Feb 2010 still turned out to be colder than average and still had one or two snow moments. 1995-96 was reasonable too - there was some cold from around the 5th Dec which lasted on and off for most of the month, and after a mild first three weeks to Jan, there was another cold spell in the last third of Jan lasting into the early part of Feb; that month then remained on the cold side.

My second choice would be to have a month long cold spell similar to pre Christmas this year from around mid-January to mid-February, even if the rest of the winter is average, as it helps to fill up tthe wo months after you have had Xmas before spring is on its way. Prior to Christmas as I mentioned before there is always Christmas to look forward to, and once Christmas is gone there is nothing to do in life until spring and March / April arrives, and I find it unthinkable to have winter ending when Christmas is hardly out of the way and to have to get through two long months of mild dross before spring is in the air.

Hmmm... no offense meant personally (no, really!), but 'unthinkable' is surely a bit over the top?!

Unthinkable would be having one's clifftop house washed away by a flash flood and losing one's family. Unthinkable is not, repeat not, the idea of a couple of milder months of weather in a winter which will now stand out as having a notably cold and snowy beginning overall. Actually we are only half way through and no-one knows how it may end. So I think a sense of proportion and perspective could be injected... It's only the weather, interesting and diverting to predict, obviously can have major consequences but we can't change it anyway.

[Kentish Man]

Er yes anyway we had a substantial 0.4C rise in the CET today taking it to 4.1C (Jan 1 - 13).

[summer blizzard]

Er yes anyway we had a substantial 0.4C rise in the CET today taking it to 4.1C (Jan 1 - 13).

Assuming that we stop short of 6C i think that given high pressure very close to us we are likely to record some low minima especially, thus i think the finishing zone will be in the 3.5C-4C range, slightly below average.

[Upgrade]

once Christmas is gone there is nothing to do in life until spring and March / April arrives

someone needs to get perspective!

[damianslaw]

Much colder minima next week with widespread mins around or below zero for the CET zone will prevent any further rising of the CET from Monday I imagine, I still think we will finish bwlow average rather than above and potentially a fair bit below average.

[kold weather]

It does seem to me that there is an increasingly good chance of us ending up below average, its not going to be much below average unless we develop another set-up like we had in December but there is enough hints to suggest a reasonable shot at below average now.

[BornFromTheVoid]

CET is 4.6C to the 14th

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

Yesterday was 10.0C. Minimum for today is 6.2C and max temps look like being around 11C, so around 4.8C by tomorrow.

Going by the 06z GFS, we'll be at

5.2C to the 17th,

5.0C to the 19th,

4.6C to the 21st,

4.4C to the 22nd.

[damianslaw]

CET is 4.6C to the 14th

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

Yesterday was 10.0C. Minimum for today is 6.2C and max temps look like being around 11C, so around 4.8C by tomorrow.

Going by the 06z GFS, we'll be at

5.2C to the 17th,

5.0C to the 19th,

4.6C to the 21st,

4.4C to the 22nd.

I suspect the CET will take a bit more of a knock than those projections - by the middle of next week the CET zone will be seeing maxes of no higher than 5 degrees and mins of 0 and below - average values will be 2-2.5 means or lower, later next week every chance freezing fog could develop and really suppress maxes.

The sun is still very weak and will do little to help raise temps during the day and with light winds and clear skies the nights could become very cold.

The charts show a similiar bearing to what we saw in late January 1992, which brought lots of freezing fog and generally quite cold weather - nothing severe but notable all the same.

[BornFromTheVoid]

I suspect the CET will take a bit more of a knock than those projections - by the middle of next week the CET zone will be seeing maxes of no higher than 5 degrees and mins of 0 and below - average values will be 2-2.5 means or lower, later next week every chance freezing fog could develop and really suppress maxes.

The sun is still very weak and will do little to help raise temps during the day and with light winds and clear skies the nights could become very cold.

The charts show a similiar bearing to what we saw in late January 1992, which brought lots of freezing fog and generally quite cold weather - nothing severe but notable all the same.

Only 1 day of the 06z had a mean below 0, and that's what you'd need by now to knock more that 0.2C off per day.

Todays maxima look like they averaged above 11C so we will probably be at 4.9C by tomorrow instead of 4.8C.

The 12z has high pressure centered over the BI more than the 06z so despite today, it would end up with the same CET figure by the 22nd.

I'd say 3.9C-4.4C by the 25th.

[summer blizzard]

From the 18th-25th both the GFS and ECWMF give a comfortably below average period though they digress in the latter timeframe because ECWMF brings in a northerly while GFS maintains high pressure over the UK. Minima will be the main story here, though maxima will also be below average. We should be below 4.4C by the 25th, so provided there is no real mild spell we have another below average month.

[ZONE 51]

The cold is coming and is staying put, should make 3.0c i would think or about..