January C.E.T

[SP1986]

Sub 2's, since 1900:

1987 0.8

1985 0.8

1979 -0.4

1963 -2.1

1959 1.6

1945 0.4

1942 0.9

1941 0.5

1940 -1.4

1929 1.3

1917 1.6

Not actually very many over 107 years.

Interesting stats there LP. Interesting how they became quite frequent around the '40's then occurred at least once a decade until 1980's.

Note the big gap between 1929 and 1940 - thats said thats almost still decadal.

So we should either have recieved a sub 2C CET reuturn by now or weve still yet tohave the mechanism - which I think would have been this year to coincide with the solar minimum but it hasnt occurred.

I too wonder if sub 2C is realistically possible in our lifetime.

[LadyPakal]

Sub 3's over the same period:

1997 2.5

1987 0.8

1985 0.8

1982 2.6

1980 2.3

1979 -0.4

1977 2.8

1966 2.9

1963 -2.1

1959 1.6

1955 2.6

1954 2.9

1952 2.7

1947 2.2

1946 2.7

1945 0.4

1942 0.9

1941 0.5

1940 -1.4

1933 2.2

1929 1.3

1919 2.9

1917 1.6

1908 2.5

Just a quick note - used the CET analyser (by Bottesford) for these.

Edited January 16, 2008 by LadyPakal

[cheeky_monkey]

statistically it is like tryin to throw a six..the odds are 6-1 each time you throw a dice...no matter how many times you have thrown the dice before and not thrown a six...so if a sub 2 Jan is a 10-1 shot ..evry jan will be 10-1 against it being sub 2 regardless of how many years we have wait for or how few.

Edited January 16, 2008 by cheeky_monkey

[Stu_London]

You only need to look at the December 2007 cold spell to realise that sub 2 is more than possible

They were pretty rare anyway so warming and unfavorable winter sypnotics just make them even more rare things - however to say they are no longer possible is a bit foolish

[SP1986]

You only need to look at the December 2007 cold spell to realise that sub 2 is more than possible

They were pretty rare anyway so warming and unfavorable winter sypnotics just make them even more rare things - however to say they are no longer possible is a bit foolish

Yes if you were working on a small scale rolling average sub 2C is possible as anomaly but based on a months CET in winter, I fear all is lost for winters in the next 100 years. After that who knows?

Nothings impossible, and as such I dont think anyone in the thread has actually said they are no longer possible but its becoming increasingly difficult to achieve in a monthly or seasonal timescale.

Besides you vould probably similarly say that the beginning of December hitting 17C and a minimum of 10C means that a December CET of 10C is possible. Its very unlikely and I believe it has as much chance as sub 2C for the month

[Snowly does it]

statistically it is like tryin to throw a six..the odds are 6-1 each time you throw a dice...no matter how many times you have thrown the dice before and not thrown a six...so if a sub 2 Jan is a 10-1 shot ..evry jan will be 10-1 against it being sub 2 regardless of how many years we have wait for or how few.

I agree thus far however, if you believe in climate change and that we are warming, the natural conclusion is that the 10-1 shot becomes more and more long odds each year to the point where it becomes an extreme longshot (thats what I believe the case to be now)

If you do not subscribe to climate change and warming then of course your outlook will be different.

[Jonnie G]

I agree thus far however, if you believe in climate change and that we are warming, the natural conclusion is that the 10-1 shot becomes more and more long odds each year to the point where it becomes an extreme longshot (thats what I believe the case to be now)

If you do not subscribe to climate change and warming then of course your outlook will be different.

I agree that cold January has become a much longer shot, and the world is warming, but I don't think global warming is the reason for this change. Somebody suggested (was it Len?) that we are seeing the results of stratospheric cooling caused by ozone depletion by cfcs, resulting in a strong polar vortex setting up over Greenland each winter. This is the thing that's changed... the persistence of that vortex. Scandinavia has had some ridiculously mild seasons of late - probably +10C in parts so far this winter, and this is of course an issue of synoptics rather than warming. The reasons behind the synoptics are a different matter, but I'd favour the ozone depletion idea over warming at the surface, or perhaps a cyclical process of some kind.

Besides you vould probably similarly say that the beginning of December hitting 17C and a minimum of 10C means that a December CET of 10C is possible. Its very unlikely and I believe it has as much chance as sub 2C for the month

No offence but that statement is absolutely ridiculous.

[Snowly does it]

I agree that cold January has become a much longer shot, and the world is warming, but I don't think global warming is the reason for this change. Somebody suggested (was it Len?) that we are seeing the results of stratospheric cooling caused by ozone depletion by cfcs, resulting in a strong polar vortex setting up over Greenland each winter. This is the thing that's changed... the persistence of that vortex. Scandinavia has had some ridiculously mild seasons of late - probably +10C in parts so far this winter, and this is of course an issue of synoptics rather than warming. The reasons behind the synoptics are a different matter, but I'd favour the ozone depletion idea over warming at the surface, or perhaps a cyclical process of some kind.

I don't have much of a firm view on what is causing c change and g warming just that they are happening, so the above could be so, yes. However whichever the case, given that I believe things have changed, I must therefore conclude that a sub 2 month would be, in the current climate, rather less expected than a 20c month - I'd put it alongside a 21c month in likelihood.

[acbrixton]

If you look at the figures around the 1860s to 1880s, December was a colder month than February on average.

1861-90 February average: 4.5

1861-90 December average: 3.8

Fascinating Mr D.

1. February in 1861-90 was milder than 1971-2000;

2. I wonder if the cold Decembers may have been linked to the frequency of 'smogs' in that month where, of course, there is the least daylight?

regards

ACB

[Jonnie G]

I don't have much of a firm view on what is causing c change and g warming just that they are happening, so the above could be so, yes. However whichever the case, given that I believe things have changed, I must therefore conclude that a sub 2 month would be, in the current climate, rather less expected than a 20c month - I'd put it alongside a 21c month in likelihood.

I couldn't agree with those odds - I feel that in the current climate sub 2 wouldn't be that hard to achieve in February if we could get mainly polar air and an anticyclonic spell, such as mid feb - mid march of both 2005 and 2006 only a fortnight earlier. Also a cold December with an inversion might manage sub 2, but for now I'm afraid the mid winter period of January has become a write off. On the other hand, a 20 month has never happened, never mind 21 so as I say, I couldn't agree with those odds.

[Snowly does it]

I couldn't agree with those odds - I feel that in the current climate sub 2 wouldn't be that hard to achieve in February if we could get mainly polar air and an anticyclonic spell, such as mid feb - mid march of both 2005 and 2006 only a fortnight earlier. Also a cold December with an inversion might manage sub 2, but for now I'm afraid the mid winter period of January has become a write off. On the other hand, a 20 month has never happened, never mind 21 so as I say, I couldn't agree with those odds.

OK, thats fair. I stick by them myself, I guess time will tell! (I will be thrilled to be proved wrong)

[wysiwyg]

I don't have much of a firm view on what is causing c change and g warming just that they are happening, so the above could be so, yes. However whichever the case, given that I believe things have changed, I must therefore conclude that a sub 2 month would be, in the current climate, rather less expected than a 20c month - I'd put it alongside a 21c month in likelihood.

20 or 21 would be a heck of an anomoly but we are talking about a chaotic system so who really knows?

[Snowly does it]

20 or 21 would be a heck of an anomoly but we are talking about a chaotic system so who really knows?

Well, we've had a 19.7 recently.... I'd say 20 is on the cards, 21 is pushing it (but was kind of the point as so is 2 it would appear these days!) Still, we'll see I suppose

[SP1986]

No offence but that statement is absolutely ridiculous.

Ridiculous? that wouldn't happen to be because you dont believe in GW would it? For many of the faults in my post you equal them in your intentions.

However lets keep this civilised. The point I was trying to make was not literal, but simply by saying that if you apply any cold spell in order to assert that a sub 2 month maybe recorded then it is equally as wise to take note that in the same logic, a mild spell such as the one we experienced in early December could just as equally signal a warming trend - but it doesn't because it is just part of the month and therefore doesn't represent the whole month.

That doesn't take into account the fact that all data and evidence shows a warming trend and one that will prove that getting a sub 2C CET in a month is difficult and its not as if anyone said its impossible. Nothing ridiculous about that is there? Unless of course you do want to provide some theory to the contrary.

[wysiwyg]

Well, we've had a 19.7 recently.... I'd say 20 is on the cards, 21 is pushing it (but was kind of the point as so is 2 it would appear these days!) Still, we'll see I suppose

Hehe as I said a heck of an anomoly only two values in the whole Hadley mean series exceed 19c but totally agree that a twenty is reasonable to expect and not just due to GW - law of averages and chaotic weather say it could happen as well.

[Jonnie G]

Note the big gap between 1929 and 1940 - thats said thats almost still decadal.

I too wonder if sub 2C is realistically possible in our lifetime.

Note the even bigger gap for January CET between 1900 and 1917....infact it's between 1897 (1.6C) and 1917 (1.6C).

Besides you vould probably similarly say that the beginning of December hitting 17C and a minimum of 10C means that a December CET of 10C is possible. Its very unlikely and I believe it has as much chance as sub 2C for the month

I didn't realise that your comment that a December CET of 2C was as likely as 10C was not meant to be taken literally.

[Jonnie G]

a mild spell such as the one we experienced in early December could just as equally signal a warming trend - but it doesn't because it is just part of the month and therefore doesn't represent the whole month.

That doesn't take into account the fact that all data and evidence shows a warming trend and one that will prove that getting a sub 2C CET in a month is difficult and its not as if anyone said its impossible.

The point abouth the examples from mid feb - mid march '05 and '06 that I quoted to SM is that they were each a month long, but I agree that getting a sub 2 month is now difficult.

As an aside, I noticed that of the sub 2 Januarys quoted by LP, 3 were sub 2, 5 were sub 1 and 3 were sub zero. It seems that once your sub 2, you're more than likely to be sub 1 also.

Edited January 17, 2008 by Jonnie G

[Jonnie G]

Ridiculous? that wouldn't happen to be because you dont believe in GW would it?

If you read my response 259 to SM you will see that I do believe in GW.

[Stratos Ferric]

why is sub 2 a gonner in our life time or sub 3 a big ask??? i dont agree at all and i dont see how either?

It's a long time since we had one. Even without GW going on in the background the stats alone would suggest something's amiss; the fact that we have GW makes the dearth of cold winter months seem rather corroborative, and tends to wipe away any smear that suggests this is merely 'bad luck'.

The point abouth the examples from mid feb - mid march '05 and '06 that I quoted to SM is that they were each a month long, but I agree that getting a sub 2 month is now difficult.

As an aside, I noticed that of the sub 2 Januarys quoted by LP, 3 were sub 2, 5 were sub 1 and 3 were sub zero. It seems that once your sub 2, you're more than likely to be sub 1 also.

I doubt that either of the period you cite was sub 3 (though I stand to be corrected - I'm away from my daily data files at present), but even if they were there's only one way of permutating 30 cold days into a month, and therein lies the rub. It's safe to assume that in the past it was not mere serendipity that allowed cold period always to align with a calendar month, where now they do not. Rather, there will have been periods of cold of longer duration - significantly longer in some case - meaning that it was much easier to land a calendar month sub 3. Not only is GW reducing intesity of cold, it is reducing persistence, and again I say it - all of this is exactly what you would expect if the PF migrated north by 2-3 degrees or so.

Not sure that once 3 is breached much colder becomes likely. SMs stats might be inadvertently selective, but I know for sure that a CF distribution of average t for any month will be close to a normal curve. The colder you go the less likely the outcome becomes.

You only need to look at the December 2007 cold spell to realise that sub 2 is more than possible

They were pretty rare anyway so warming and unfavorable winter sypnotics just make them even more rare things - however to say they are no longer possible is a bit foolish

Strange comment to make Stu when December came in at 4.9C. You cold equally as well argue (on the basis of the start to the month and the end) that 9C is in bounds. It's the same argument as I had with WiB during autumn when he was playing the "but if it IS cold by mid month then a very cold outcome becomes more likely". The argument falls down because the longer any spell of weather goes on for, the less likely it is to endure. Half a cold month proves nothing other than that half a cold month is still possible. I can run a mile in 5'30" when I'm in full training, but I sure as hell can't run two miles in 11'00". That's how it seems to be with the weather nowadays I'm afraid. To be sure of a cold calendar month, you really need the weather to be capable of staying very cold for 40 days or so. It simply doesn't happen any more, not nearly, not for a long time.

[Roger J Smith]

That was an interesting post by Mr Data -- I had a look at Toronto records to see if the same phenomenon showed up there. February in Toronto averages about 2 C colder than December and just barely a fraction above January. Sometimes in the 19th century February was colder than January in certain decades. But there was no sign of this trend of December being colder than February. In that period it remained 2 C milder on average.

However, December does tend to be colder than February in coastal BC here, and I attribute this to the proximity of stronger arctic highs. Possibly then the 1861-90 period featured stronger arctic highs in general on the European side of the arctic basin as well, so that they were able to do their thing on a more frequent basis. It still remains the case in the modern climate set-up that December inversions can be colder than February inversions, at least the one in Dec 06 seemed colder than anything recent in February.

ACB may also have a point about the coal burning reinforcing the degree of cold in these inversions, in fact, I would imagine a case could be made for that right through to about 1975. Even without all that coal, the 1980s did alright though.

By the way, what is going on with the 16-day temperature forecast on the home page here? Those are seriously out for the next five days, it's never going to be that cold surely anywhere in the UK let alone on average. Did they drop 10 from the calculations or what happened there?

Edited January 17, 2008 by Roger J Smith

[Weather-history]

That was an interesting post by Mr Data -- I had a look at Toronto records to see if the same phenomenon showed up there. February in Toronto averages about 2 C colder than December and just barely a fraction above January. Sometimes in the 19th century February was colder than January in certain decades. But there was no sign of this trend of December being colder than February. In that period it remained 2 C milder on average.

However, December does tend to be colder than February in coastal BC here, and I attribute this to the proximity of stronger arctic highs. Possibly then the 1861-90 period featured stronger arctic highs in general on the European side of the arctic basin as well, so that they were able to do their thing on a more frequent basis. It still remains the case in the modern climate set-up that December inversions can be colder than February inversions, at least the one in Dec 06 seemed colder than anything recent in February.

Here's the thread about the number of really mild Februarys in that period

http://www.netweather.tv/forum/index.php?showtopic=34523

[Kentish Man]

Hadley is 5.5C today (Jan 1 - 16) which by coincidence is my guess for the month. Unfortunately it looks like going higher than that so I suspect RJS will be in with an excellent shout as he will win this month's competition if the landing zone is anywhere betwen 6.2 and 7.1.

Edited January 17, 2008 by Kentish Man

[reef]

Going by the 6z GFS we would be at around 6.2C by the 24th. If the month were to finish at that level, it would be the 8th warmest January since 1900. Not quite as bad as last year, but at 2C above the 1971-2000 average, would put it into perspective of how poor a month it has been for cold (outside of Scotland and Northern Ireland anyway).

[Stratos Ferric]

Going by the 6z GFS we would be at around 6.2C by the 24th. If the month were to finish at that level, it would be the 8th warmest January since 1900. Not quite as bad as last year, but at 2C above the 1971-2000 average, would put it into perspective of how poor a month it has been for cold (outside of Scotland and Northern Ireland anyway).

Indeed, and it would just continue to reinforce the point that for all that we've had a cold month in the last eight or nine, the cold is never anything like as extreme as the warm is when it comes along.

[North-Easterly Blast]

Last July and August were below average. The second half of 2007 was the coolest for 11 years. It is noticeable that even the above average months in the second half of 2007 were not especially warm. January looks well and truly set to be the first significantly above average CET month since last April.