344 replies to this topic

[Mark22]

Thanks guys. That was a massive help.

[The PIT]

Back to rapid rises here again after a pause this weekend. I'm on 2.7C now up from 2.3c yesterday.

[BornFromTheVoid]

2.6C to the 21st
http://www.metoffice..._info_mean.html

Yesterday was 7.3C. Minimum today is 8.0C while maxima will probably be a little over 10C, so we'll probably be around 2.9C tomorrow.
After that, with the 12z GFS, the CET will be at
3.3C to the 23rd (12.7)
3.7C to the 24th (12.0)
3.9C to the 25th (8.1)
4.0C to the 26th (7.3)
4.3C to the 27th (12.0)
4.6C to the 28th (12.3)
4.7C to the 29th (8.9)

Could end up very close to the 1981-2010 average after corrections.

[damianslaw]

Looks like a sub 4 degree CET is becoming increasingly less likely, with downward corrections something in between 4-4.5 degrees probably most likely so a very average CET despite the sub zero first half. It will go down as a month of two halves very much like what happened in 2009 when the cold first half was cancelled out by the very mild second half.

Alos looks like being a very dry Feb for many parts of england and wales (so here mind!) - Feb can be a very dry month and the driest of the year in some places something which still surprises some people.

[Don]

damianslaw, on 22 February 2012 - 22:25 , said:

Looks like a sub 4 degree CET is becoming increasingly less likely, with downward corrections something in between 4-4.5 degrees probably most likely so a very average CET despite the sub zero first half. It will go down as a month of two halves very much like what happened in 2009 when the cold first half was cancelled out by the very mild second half.

Alos looks like being a very dry Feb for many parts of england and wales (so here mind!) - Feb can be a very dry month and the driest of the year in some places something which still surprises some people.

I'm going to be too low yet again with my CET guess, this time by around 1C. I think Feb 2012 will turn an overall CET value very close to that of 2009 (4.1C), although if anything it will probably be slightly higher. Certainly wasn't expecting this two weeks ago!

[Scorcher]

Could be a huge rise after today- if anything GFS may be underestimating the mildness with most places staying in or close to double figures overnight. After 10 days I was seriously concerned about my estimate of 5.0C but I might not be too far off now after all.

[North-Easterly Blast]

This February could be a record breaking month for the largest increase in CET from the first half to the second half. The largest increase ever occurred in Feb 1799, where the second half was 7.8*C warmer than the first half. The first half of that month came in at -1.1, and the second half at 6.7. In winter 2010-11 we saw the most pear shaped winter on record, so if this February turns into the largest increase ever from the first to the second half, then the most pear shaped February on record will have occurred in the winter following on from the most pear shaped winter season on record.

Also another possible record is that Feb 2012 could turn out to record the warmest second half of February since before 1772. The warmest second half of February ever so far was in 1926, which saw a CET of 8.4*C.

[Scorcher]

I'd imagine today will be close to a record for a February daily CET value as well, have to wait and see.

[North-Easterly Blast]

Scorcher, on 23 February 2012 - 16:10 , said:

I'd imagine today will be close to a record for a February daily CET value as well, have to wait and see.

Hadley has the minimum down as 8.6, and the maxima I would suspect should be around 15.5. It is probable that today will come out with a daily CET over 12*C, but I doubt that it will reach the warmest CET day ever in February, which was 12.9 on Feb 4th 2004.

[Scorcher]

North-Easterly Blast, on 23 February 2012 - 16:53 , said:

Hadley has the minimum down as 8.6, and the maxima I would suspect should be around 15.5. It is probable that today will come out with a daily CET over 12*C, but I doubt that it will reach the warmest CET day ever in February, which was 12.9 on Feb 4th 2004.

Hmm ok I was expecting the minimum to be higher than that, can't see it happening then. That's amazing that the record CET day occurred at the beginning of the month in 2004.

[North-Easterly Blast]

We have come close to average for the CET in February four times in the last ten years, but only on one occasion recorded a colder than average February, in 2010. Three of the occasions we have come close to average for the CET were down to bad luck that we didn't record a colder month.

Feb 2005 was dominated by northerlies and easterlies persistently after the 12th, and saw some wonderful easterly synoptics from the 20th onwards, later backing northerly, yet the synoptics failed to bring anything particularly cold, and the average for the last nine days was 1.5. With the coldest possible synoptic setup, I would have expected a well sub zero last nine days, but it wasn't. Given the synoptics of Feb 2005, it was a big let down that the month recorded a CET that was still a shade above average, when the synoptics ought to have produced a much colder month.

Feb 2006 again saw an easterly setup at the same stage in the month as 2005, but this was even less potent than the Feb 2005 easterly, and the CET was over 3*C in this nine day spell, and some days in that spell even failed to come in below average. These late Feb 2006 synoptics should have produced colder temperatures than they did; as such it was a let down that the CET for that month was still close to the older 1961-90 and 1951-80 averages, when the synoptics later in the month ought to have been cold enough to bring the month's CET down to less than 3 degrees.

Feb 2009 saw a cold snowy spell in the first half, yet went belly up in mid-month and gave way to a very mild second half with the overall result that the month's CET was in the end close to the average, or even slightly above the older sets of averages.

Now Feb 2012 has gone the same way as Feb 2009, and even could well exceed the pear shapedness of Feb 2009, and will again fail to bring in a colder than average month, by the older 1961-90 and 1951-80 standards at least.

What does it take to get a colder than average February;we managed it in 2010, but how rare was that?

[cheeky_monkey]

cold Februaries were quite common in the 60s 70s and early to mid 80s..since then apart from 1991..there hasnt been a very cold February..recently the cold January bogey has been broken by Jan 2010..and December has never really strayed from the path.

[North-Easterly Blast]

cheeky_monkey, on 23 February 2012 - 18:37 , said:

cold Februaries were quite common in the 60s 70s and early to mid 80s..since then apart from 1991..there hasnt been a very cold February..recently the cold January bogey has been broken by Jan 2010..and December has never really strayed from the path.

Yes it is certainly true that the mildness in the 1990s and 2000s winters was loaded in January and February whereas December often tended to be close to the long term average. In fact in the last 20 years, December has been at least 1*C below the long term average (by 1961-90 / 1951-80 standards) on seven occasions. Whereas in the last 25 years, January has only been at least 0.5*C below average on five occasions, and 1*C or more below average on two occasions. Also in the last 25 years, February has been 0.5*C below average on only four occasions, and 1*C or more below average on three occasions.

[Snow? norfolk n chance]

snow? norfolk n chance, on 22 January 2012 - 18:53 , said:

settled ish first half, but not cold like 14-17 Jan, Atlantic dominated 2nd half, 5.1C

something like 2.0C first half, 7.1C 2nd half

22nd Jan, not looking far out I dont think, maybe too low though 5.1C, unusual for me to predict winter CET's too low

[Nigerian Prince]

15.0c thats the maximum here at Battersea,London its now 12.3C, and falling, under clear skies of course, so the minimum should be lower tonight,yes, quite an amazing end to February, its been a long time since we had a February that was quite below average, a regular occurance, before 1987, in the years before that, you could almost guarantee( even in the milder years )an Easterly developing in the second week of February. January as not change much in nature, its as got milder, but by not a great ammount, it was nearly always a mild month in the past. December as actually got colder in general, strangly enough, many Decembers in the 1980s were very mild, 1981 being the main exception to this. One thing is for sure,since September the sequence of mild of month dominated by southerly, westerly, winds is incredible, I can not remember seeing a period like it, since September high pressure as stayed to the South West, South and Southeast with little or no break, I know that many places in the South and South East, and Central England had 2 weeks of Easterly winds end of January, February, but for many in the Southwest, Ireland, and Western Scotland, there as been little or no break from this dominant weather pattern.

[North-Easterly Blast]

2006-07 was a similar match to the last six months in terms of persistent warmth at the same time of year (autumn and winter) though Jan and Feb 2007 were still quite a bit milder than this year.

A year in the more distant past which was similar to the last nine months or so was in 1898-1899. In 1898 the July was on the cool side, but like in 2011, in July 1898 the mean minimum was low but the mean maximum wasn't especially so. In 1898 the autumn was on the warm side, though less so than in 2011, and the winter of 1898-1899 was very mild with little in the way of cold spells, and little snow, and even milder overall than winter 2011-12 will turn out.

OK, the weather in the last nine months may not match the weather from June 1898 - Feb 1899 exactly month by month, but those nine months of that year bear striking similarities to the same period during these last nine months..

[damianslaw]

I'm surprised how mild maxima got up to today - we didn't have wall to wall sunshine and a deep seated southerly - I'm sure we have had many similiar synoptics set ups during many Febs which failed to deliver maxima of 18 degrees.

Feb in recent years has often been a month of two contrasting halves, 2009 saw a cold first half and very mild second half - like this year, 2008 saw an unsettled first half followed by a very dry sunny second half, 2005 and 2006 saw colder second halves and mild first halves. Feb 2010 was consistently cold - nothing exceptional but it was a decent winter month, but such months have been very rare in the last 25 years, even 1991 ended with a mild last week.

This feb cet value masks a month of two very contrasting halves with hardly any average conditions, just cold/very cold, or mild/very mild. This winter also must go down as one of the most least northerly/easterly ever, with winds predominantly coming from a west to southeast direction, with very shortived northwesterly winds - can't remember the last true northerly - probably last July - when they are no good to anyone.

[North-Easterly Blast]

damianslaw, on 23 February 2012 - 22:45 , said:

I'm surprised how mild maxima got up to today - we didn't have wall to wall sunshine and a deep seated southerly - I'm sure we have had many similiar synoptics set ups during many Febs which failed to deliver maxima of 18 degrees.

Feb in recent years has often been a month of two contrasting halves, 2009 saw a cold first half and very mild second half - like this year, 2008 saw an unsettled first half followed by a very dry sunny second half, 2005 and 2006 saw colder second halves and mild first halves. Feb 2010 was consistently cold - nothing exceptional but it was a decent winter month, but such months have been very rare in the last 25 years, even 1991 ended with a mild last week.

This feb cet value masks a month of two very contrasting halves with hardly any average conditions, just cold/very cold, or mild/very mild. This winter also must go down as one of the most least northerly/easterly ever, with winds predominantly coming from a west to southeast direction, with very shortived northwesterly winds - can't remember the last true northerly - probably last July - when they are no good to anyone.

The first half of Feb 2006 wasn't that mild; in fact in 2006 the second half was slightly milder than the first half. You are correct about Feb 2005 though. I can also add another contrasting Feb to the list - 2004. That year the first half of Feb was very mild, with an exceptionally mild first week. It then turned colder from the 20th, resulting in Feb 2004 seeing a second half about 5*C colder than the first half.

Regarding this winter and how it will turn out, yes it has been significantly milder than the last three, although not as mild as 2006-07 and 2007-08. Although on one hand even despite not being cold, the post Xmas part of winter 2011-12 could turn out to be slightly colder overall than the post Xmas part of winter 2010-11, and the two week cold spell we got this winter from the end of Jan through until almost mid Feb was colder than anything that winter 2010-11 delivered after Christmas. Basically winter 2011-12 has not been much different to 2010-11 apart from being without a cold spell to begin with. Most parts of the country have seen below average snowfall, and a number of areas have seen little snowfall, but if anything the post Xmas part of winter 2010-11 saw very little snow and was virtually snowless for most of Britain.

Edited by North-Easterly Blast, 23 February 2012 - 23:26 .

[West is Best]

North-Easterly Blast, on 23 February 2012 - 23:13 , said:

Basically winter 2011-12 has not been much different to 2010-11 apart from being without a cold spell to begin with.

Oh I'm sorry but I really can't let that comment slip through unchallenged!

Winter 2010-11 did indeed have a mild second half but it delivered the first sub-zero CET month for a quarter of a century and was the coldest December for over 100 years. At -0.7C for the whole month that was incredibly cold. It was also widespread.

As has been pointed out, the little cold snap in the eastern half of the UK this month hardly touched the far west.

The CET last winter despite the mild February was 3.1C. This year's CET is going to come out somewhere close to 5.1C which is a full 2C warmer than last year, a big amount for meteorological winter. Even January 2011 will be colder than anything winter 2011-12 will have produced if, as expected, the one colder offering this year rises up to near 4C.

And I haven't even mentioned the snowfall, which in 2010-11 was both intensive and extensive. Many parts of the UK this winter have seen nothing at all, and those who did saw something fleeting for a few days.

I couldn't leave that unchallenged because I think it's very wrong. Empirically winter 2010-11 was far colder.

[North-Easterly Blast]

West is Best, on 24 February 2012 - 05:50 , said:

Oh I'm sorry but I really can't let that comment slip through unchallenged!

Winter 2010-11 did indeed have a mild second half but it delivered the first sub-zero CET month for a quarter of a century and was the coldest December for over 100 years. At -0.7C for the whole month that was incredibly cold. It was also widespread.

As has been pointed out, the little cold snap in the eastern half of the UK this month hardly touched the far west.

The CET last winter despite the mild February was 3.1C. This year's CET is going to come out somewhere close to 5.1C which is a full 2C warmer than last year, a big amount for meteorological winter. Even January 2011 will be colder than anything winter 2011-12 will have produced if, as expected, the one colder offering this year rises up to near 4C.

And I haven't even mentioned the snowfall, which in 2010-11 was both intensive and extensive. Many parts of the UK this winter have seen nothing at all, and those who did saw something fleeting for a few days.

I couldn't leave that unchallenged because I think it's very wrong. Empirically winter 2010-11 was far colder.

Winter 2010-11 was the most pear shaped winter on record. It was completely without precedent to see such an extreme pre Xmas freeze up to deteriorate into next to nothing when Xmas was barely over. In fact after Dec 27th conditions were average at best, and any cold spells were due to high pressure sat over the UK, and not deep cold Arctic air. February was then very mild and devoid of anything cold. Something like winter 2010-11 had never happened before. Put it this way, take out the period 1st - 27th Dec 2010 out of the equation, then the entire post Xmas part of winter 2010-11 has a CET of 5.0, not the 3.1 that it ended up. It shows how a winter can be notable for having a notable severe spell in an otherwise average to mild winter, and not a cold winter overall; a bit like 1986-87, take out two weeks alone from the 7th - 20th Jan, and you add 1.1 to the overall CET, making it 4.6 rather than 3.5.

Lets look at winter 2010-11 to see how pear shaped it was. Despite January returning a CET close to the 1961-90, 1951-80 and older averages, it was 4.4*C warmer than the previous December, making it the third largest increase from December to January on record. The 7.1*C increase from December to February in the same winter is by some way the largest on record.

If Feb 2012 comes out with say a CET of 4.0, which seems possible; Jan 2012 had a CET of 5.4, then the average for Jan - Feb 2012 will be 4.7, which will be slightly colder than Jan - Feb 2011, which had a CET of 5.0 combined. So there is still a possibility that the post Xmas part of winter 2011-12 will be slightly colder overall than the post Xmas part of winter 2010-11. So on one hand two thirds of winter 2011-12 could turn out to be slightly colder overall than the same two thirds of winter 2010-11, making the only difference being that 2011-12 was without the cold spell pre Xmas compared to 2010-11.

Edited by North-Easterly Blast, 24 February 2012 - 07:47 .