Metomania

Sorry, but this way lies madness methinketh. We're playing with fire. There is absolutely no guarantee that this warm-up will actually shut down the gulf stream. It's one theory that is as yet totally untested. Pinning our hopes that ice-melt will stop the gulf stream is like a rival team hoping the winning driver is going to run out of petrol on the peunultimate lap. It might happen, but it's a hell of a risky strategy.

Indeed - I'm within a stone's throw. Great site, and good people there!

Great link Devonian - says it all, so you don't need to back down. You are clearly right to have said what you did. That graph within the link is deeply shocking. Here it is in all its awful glory: (p.s. I take it you are in Devon? I'm in Exeter ...)

Hi Carinthian. Whilst observations are always very useful, and make a great contribution to scientific endeavour we need as extensive and objective a means for measurement as possible. I've just posted two graphs above that are very difficult to argue with, and a report from the Masachussets Insitute who are researching in this area. I'm afraid, notwithstanding your 'observations' it does look as if we are in uncharted territories in terms of ice-melt now this year.

Yes, and I agree. Shocking report in today's Telegraph about sea ice melt in the arctic circle. The Oceanographic Institute at Massachusetts reports water as warm as 7C at the moment in parts of the shelf from the Bering Sea to the south - more than 6C higher than at the same time two years ago. Ice melt this extensive, this early in the season, is shocking. Rather than listening to 'oh yes it is, oh no it isn't' posts from cold rampers vs mild rampers, the facts speak for themselves. These graphs are pretty shocking, showing that we're indeed about to see the lowest ice levels in the northern hemisphere this summer, and unprecedented ice melt. GW incontrovertible on this sort of evidence ...

As far as we know there has never been such a steep temperature increase on this planet. No archaeological or palaeontological proofs can be found for anything so unprecedentedly sharp as the warm up in the twentieth century. With the ice caps melting faster than ever (yet another bleak report out today about the arctic ice caps melting - 6C above average in some places) you certainly cannot rely on snow fall in this way. To point out the obvious, the heavy ppn this year in the Rockies may have fallen as snow high up, but fell as unseasonal rain lower down. You only have to ask residents of the mid-west US or places like Calgary and they would gladly tell you how bizarrely snow-free this winter was for them. I know where you are coming from with this, but your application of a theory about cool-down to the actual facts looks to me like you end up simply distorting those facts.

Indeed! B)

Interestingly, because people might not realise this, the huge snow depths in the Rockies have coincided with massive warm anomalies this winter. It has been the warmest winter in the Rockies in living memory, but with big snow depths in some resorts. So don't let anyone dare, even dare, start dragging ice age theories into that!

As a matter of interest, why? Do you not like spring?

Just crossed the 7C mark on NW. (Philip's 6.6C was yesterday) Touch and go whether we'll get to 8C by Monday night. My only slight disagreement with Stratos Ferric's otherwise excellent posts is that some serious warmth is beginning to show up on the model outputs now. It's remarkable just how quickly a month can turnaround. Whilst a cool outcome is still possible, it's not at all implausible that we could have something well into the 9's, and even into the record-breaking zone of the 10's. A long way to go, and really anything can happen. The models suggest warmth ahead though.

Is the total lack of interest on NW in this story, which is running as a headline on lots of news channels, because: - No-one here agrees? - Most people here don't want to agree? - Most people do agree, but don't want to think about it? Or a combination of these, or none?!

Others may have some views, but it's ok as long as we just make clear it's really tentative and rough. The uncertainty though is what makes this monthly CET thread (and now I see an annual one creeping in!) such a piece of fun. It's a bit of a lottery really! It all makes the Met Office winter forecast so impressive ...

Yes. Don't use it for long-range temperature guestimates. Seriously, model outputs are wayward enough past T+5 days on synoptics. To try and use them to second-guess actual temperatures that far out, and then state 'this is what the CET will be' is about 4 leaps of faith too far. If forecasters caution about synoptic certainty at that range, it is quadruply dangerous to use them for temperature certainties.

SB I have to question your ability to make definitive statements about temperatures in the future. Using the GFS runs in the way you do is very inaccurate. The CET is now rising fast. Philip had it at 6.3C to yesterday (not 6.1) and the NW tracker which is several hours ahead is approaching 6.7C. The tracker CET should be somewhere around 8C by the end of the Easter weekend, or average. Thereafter we will need to see what the synoptics produce, but if second-guessing synoptics that far ahead is fraught enough, stating temperatures is folly.

As I said, it should be near average which is either 7.9C or 8.1C depending on which benchmark you use. I'd agree that 8.5C might be a tad much. Night-time temps don't look particularly cold to me. GFS always under-estimates temps in these conditions. Edit - Mike W: I have no idea what your post means?!

Yes I'd agree that 8.5C might be pushing it. I suggested it might be around about average by the end of the Easter weekend. As you'll know the averages for April are as follows: 1961-1990 7.9 1971-2000 8.1 1906-2005 8.1 Something around 8C by Monday night looks fairly reasonable to me.

Is it only 4 weeks since people were saying the same thing about March?! Unlike March, I can't see an awful lot to support such an assertion. Even the cool-looking 0z and 6z runs need to be taken with a lot of caution because there is considerable scatter with control on the cold side. The likelihood of the CET being back up to near average by the end of the Easter weekend is, as Roger points out, still considerable. Much will therefore depend on the final week of the month - a week which statistically is less likely to be as cold as the first week of the month. Somewhere in the range 7.5C to 10C looks likeliest from this point, but there is very little at this stage to justify comments about coldest in last 60 years. I don't incidentally usually like criticising other forecast sites, but the TWO CET is beyond a joke. They seem to adjust their figure in the most arbitrary manner, and the result is consistently the most inconsistent "CET" in the business, which bears no relation at all to the official Hadley CET, nor to that of Philip Eden. The fact that they even dare to call it 'CET' adds insult to injury ....

No I put a sentence saying that we don't know the Hadley figure for February yet, and that caution was needed on that front. However, the 3.8C is based on Philip Eden calculating the Hadley figure. He not only gets their info but knows the method they use for adjustment so he can normally tell us what the Hadley figure will be. For February he reckons 3.8C and for March 5C.

Sorry, I missed this excellent post and never responded. Whilst I would often agree with this in statistics I am not sure climatology makes it quite so clear-cut. The issue revolves around what 'short-term' means in metereology doesn't it? Except for the exceptional warm up at the end of the C20th patterns in climatology are surely measured over decades? There is little doubt that the 1961-1990 mean is 'unfairly' cold, but that the 1971-2000 is also rather warm. It's true these might be indications of patterns, in which case climate change is measurable over what would be considered in metereological terms incredibly short time-spans. But I do take your point. On balance I rather like Philip Eden's suggestion of using the 1971-2000 mean, but also referencing how this compares to the last 100 years.

It has indeed been very interesting to see the record breaking run of mild months broken, but I think we need to be a bit careful about hyperbole here. In that sequence stretching back a year and a half, some months were actually very close to being average e.g. February 2005 at 4.3C was statistically average; May 2005 was average against the last 100 years; August 2005 was average to the 1971-2000 mean; whilst October 2004 was actually below the 1961-1990 average so the sequence on that scale was never 18 months anyway. The last 5 months have been interesting as I say, but none of them has fallen into the 'well below' average category (the correct metereological term I believe rather than 'a fair bit' ) except March 2006 against the 1971-2000 mean (but not the other two means). 3 of the 5 months are indisputably statistically below average (but not well below), with February below against two means but not the other. We need to bear in mind too that neither February nor March have been published by the Meto Hadley department as yet, not that there will be any doubt that March will come in below. November 2005: 6.2C which is 0.3C below the 1961-1990 average; 0.7C below the 1971-200 average; 0.3C below the 100yr rolling December 2005: 4.4C which is 0.2C below the 1961-1990; 0.8C below 1971-2000; 0.3C below 1906-2005 January 2006: 4.3C which is 0.5C above the 1961-1990; 0.1C above the 1971-2000; 0.4C above 1906-2005 February 2006 3.8C which is the same as the 1961-1990; 0.4C below the 1971-2000; 0.1C below the 1906-2005 March 2006: 5.0C which is 0.7C below the 1961-1990; 1.3C below the 1971-2000; 0.9C below the 1906-2005 Overall winter 2005/6: 12.5C which is: 0.3C above the 1961-1990 average (12.2C) 1C below the 1971-2000 average (13.5C) 0.2C below the 100 yr rolling 1906-2005 average (12.7C) As for April ... expect a significant rise in the CET over the next week or so. It obviously statistically rises as the month progresses because the thermal gradient is so much steeper as the month passes, and the synoptics are lined up for a rise of some proportion now. For April to come in below average will need a really cold spell after the next week of westerlies. Ironically it is settled high pressure that can help peg it back because notwithstanding the warm days, at this time of year sharp frosts are still very possible and these can really knock the CET down. For the next week minimum temperatures are likely to be high, and this will cause the steep CET rise.

It is too early to make a statement like that. We are now set for a week of mild conditions, and without air frosts likely the mean will rise fast. The final 10 days will decide the month, and at this stage it looks warm so an above average month is very much still on.

Just wanted to pick up on one other statistical point that was put around. It was suggested that March has a greater temperature variation than any other. I cannot at the moment judge that, but in terms of the warmest and coldest examples of months in the last 100 years, March is nowhere near the most variable month. That honour belongs to January, closely followed by February. May and June are the months with the least statistical deviation from the mean. Here are the greatest variations over the past 100 years between the warmest and coldest of any given month: January: 9.6C February: 9.2C March: 6.5C April: 5.1C May: 4.4C June: 4.3C July: 5.8C Aug: 6.3C Sep 4.9 Oct: 6.5C Nov: 7.3C Dec: 7.8C This may be a game with statistics, but it does suggest that historically there is less 'to play for' between April and September. It suggests that English summers are relatively consistent. English winters are not. (But we probably all knew that!) Sorry Philip - I was typing this up whilst you posted your infinitely more important post. Didn't mean to steal your thunder (or daffodils).

Astonishing! What a great forum this is!

1996 at 4.5C. Before then there were a string of cold Marches in the 1980's. Between 1979 and 1987 there were no fewer than 6 sub 5C March months: quite incredible. In 2001 it was close at 5.2C Hadley CET can be viewed here: http://www.meto.gov.uk/research/hadleycent.../HadCET_act.txt

There's a few of 'em around these parts! Philip Eden has just made the very sensible point that where he can he uses the latest 30 year rolling average + he puts a stat comparing it with the last 100 years' figure as well. He put it better than that in the March CET thread. It seems a good idea as it avoids too much confusion. I cannot really see why a couple of days latitude shouldn't be given. It hardly gives anyone very much advantage to have a day or two extra. It would only be if you got to the middle of the month that it might become unfair! Or if you change it half way through!