主播大秀

"Current computer projections suggest that December is unlikely to be another washout month dominated by the Atlantic. "

Yup, Met talking about a "Sudden Stratospheric Warming" disrupting westerlies:-

"For the UK in winter, that means a disruption to the westerly flow that usually brings mild air from the Atlantic and there is a potential to allow easterly winds to take hold, bringing in cold air from the continent."

Full post:-

"Cold weather clue in upper atmosphere"

Some people perform better in cold conditions, i always feel Christa stands out when it gets nippy.
Bring on the snow...

Paul I can remember the weather men going on about the drought conditions in spring, that it would take years to recover from it, even if we were deluged by rain. It was suggested that the weather had been too dry the last few years. Watch out for the cold and snow to throw even more scorn on predictions of man made global warming. Happy white Christmas Tim.

Interesting post Mr Hudson, but it would have been nice to see some numbers or a graph alongside a statement like "but the 1920's sequence is nothing like what we have experienced in recent years."
As it stands, it's difficult to get a grasp on the relative difference which leads you to say "suggests that over and above any cyclical change to weather patterns that are naturally occurring"

4. lateintheday wrote:

"... it would have been nice to see some numbers or a graph alongside a statement like "but the 1920's sequence is nothing like what we have experienced in recent years."

Yes, I thought that was a slightly odd comment.

You can download the UK precipitation data from here and work out your own graphs, LitD:

The current period, in terms of both the last ten years and the decade 2001-2010 was wetter than the 1920s in the UK, but only by a few mm per year on average.

Not sure if that warrants the term "nothing like we've experienced"? It's pretty close.

Perhaps Paul was referring to some other aspect of it that we've overlooked?

5. newdwr54 wrote:

Not sure if that warrants the term "nothing like we've experienced"? It's pretty close."

Yup, also why "Across England and Wales", why not the UK?

'Such a rainfall sequence suggests that over and above any cyclical change to weather patterns that are naturally occurring, other factors are likely to be at work, fuelling suspicions that climate change is playing its part.'

Why?

Other factors.... fairy dust?

fuelling suspicions... by who, Greenpeace?

tsk,tsk.

7. ukpahonta wrote:

"Why?"

I don't know, whilst I try very hard to stick to observational data, it is difficult not to think that we are in the Climate Pantomime Season! I am sure there has been an increased activity in the "catastrophic" claims, and that the claims are becoming more and more out of step with reality.

Either Nature = The Real World, decides to change its present pattern or there has to be a major change in the "group think" of its inhabitants.

Either way there will be tears, our priority should be to reduce the amount of tears that are shed for those that suffer unnecessarily.

Met office research says overall UK rainfall has increased in recent decades and suggest this is what would be expected in a warmer atmosphere as it would hold more moisture. My question to Paul Hudson though is this. In recent years summers have been wet and winters dry. How does that square with climate projections (based on global warming) of drier summers and wetter winters?

9.Gadgetfiend wrote:

鈥淗ow does that square with climate projections (based on global warming) of drier summers and wetter winters?鈥�

Welcome to:-

My Climate Change Garden!



"Kew Gardens planted The Mediterranean Garden in 2007 to educate and encourage gardeners to think about the wide range of drought loving plants that will survive our hotter summers. The plants are well established despite the record summer rainfall of 2007/2008 and are simply loving the mercury busting temperatures so far in 20011(sic)"



鈥淢y Climate Change Garden!鈥� Just how many that know now鈥檛 about ow't are on this 鈥済roup think鈥� gravy train?

thanks for the link newdwr54.

How come the year 2007 did not make it into the top ten, with the solid two months of very heavy rain night and day, every single day. This caused devastating floods, particularly in the North and also in the South such as Tewkesbury.

From previous thread:-

lateintheday wrote:

鈥淥n a related note, (and probably stupid) but does anyone know if the Walker circulation picks up any of the antarctic sea ice melt and then transports it via humboldt current toward the central pacific?鈥�

I thought it was the other way around 鈥� Humboldt brought cool water up the coast of South America and the Walker Circulation (trade winds) transported it toward the central pacific?

Can I take it you have been watching developments off the coast of Ecuador?

"Such a rainfall sequence suggests that over and above any cyclical change to weather patterns that are naturally occurring, other factors are likely to be at work, fuelling suspicions that climate change is playing its part."

Not really.

The jets just moved south because of natural cooling and happen to be stuck for the time being, again from natural causes.

Most likely the rate of cooling has stabilised for a while leaving the jets across us.

If the rate of cooling accelerates they will move further south and we get drier.

If the cooling turns back to warming they will move north again and we will get drier.

"My question to Paul Hudson though is this. In recent years summers have been wet and winters dry. How does that square with climate projections (based on global warming) of drier summers and wetter winters?"


i) Drier summers and wetter winters for the UK occur when the jets are north of us. That is what the alarmists expected.

ii) Wetter summers and drier winters for the UK occur when the jets are south of us.

Therefore the recent changes must be natural and there is no sign of any anthropogenic component.

The temperatures are now starting to go into a trough. The weather was exactly like this before we had the sever weather the year before last. I suspect the heavy snow will start to come in January. buy your snow shovels early.

I've been trying to figure out what Paul Hudson meant by "the 1920's sequence is nothing like what we have experienced in recent years" by messing around with the UK rainfall data:

The only thing I can come up with is if you look at the data as long term average rainfall. 30 years is the recommended period for identifying trends in surface temperatures, so applying that to rainfall in the UK, then the past thirty years is indeed quite a bit higher than any average 30 year period that includes the 1920s. (The first full 30 year average starts in 1939, because the data series only starts in 1910; but the 1920s are included in all 30 year averages up to 1959).

Before 2004, the 30 year period with the highest average was 1910-1939, with 1,101 mm/decade. Then there was a gradual decline, bottoming out in 1981, with the period 1952-1981 experiencing 1,049 mm/dec on average. After that it rose sharply. The thirty year period ended 2004 surpassed the one ended 1939 for the first time (1,103 mm/dec), and it all peaked in 2009, with 1972-2009 averaging 1,213 mm/dec.

It's slackened off a bit since then, but if we get 2/3s December average rainfall this year, then the thirty year period ended 2012 will still be around 30 mm/dec wetter on average than any 30-year period that includes the 1920s.

I think that must be what Paul means by the "nothing like what we've experienced in recent years" comment. I thought for a minute there he'd made a mistake, but probably not after all. He's pretty smart, old Paul, isn't he?

16.Ukip wrote:

"buy your snow shovels early."

Thanks Ukip; I'll see if my aunt in Toronto is selling hers:

Re: 17,

Sorry, I keep saying 'per decade' because I'm usually discussing trends with GS. In fact those figures in #17 are the *annual* average for the whole 30 year periods in question.

It's the same odds though. The last 30 years have been on average about 30mm per year wetter than any 30 year period that included the 1920s.

Greensand@13 "I thought it was the other way around 鈥� Humboldt brought cool water up the coast of South America and the Walker Circulation (trade winds) transported it toward the central pacific?"
Well you know how it is - you read a few bits and bobs and a picture forms in your head. In this instance, a few bits came together to form what was probably an entirely stupid thought. As you state, the strength of the trade winds seem to drive the amount of cold water upwelling but what determines the relative coldness of the subsurface pools? I then read recently (Shephard, I think) that antarctic melt moves around geographically so that for example, an area in the East may see growth for a couple of years followed by a year or two of reduction. It then struck me that floating ice is subject to stress points. The further out a sheet extends, the more vulnerable it becomes to fracturing. AHA - me thought! Wonder if that's where the variation in temperature of cold upwelling water is coming from. Taking it one step further, I then considered how antarctic ice loss, just in the right place, and then processed through ENSO might actually be part of the polar see-saw. It's genius I tell you! Sheer genius.
Thing is, I read a Tisdale post today which described ENSO very well. After digestion, I now consider my eureka moment the dumbest thing since sliced bread. Ho hum...
I know I didn't have to fess up, but you did ask.

Stephen Wilde,

I have been following Wayne's thread over at Tallblokes:

Maths over my head but logic is impressive. Seems to be gaining ground from variety of players. I see that you have a post up on your site simplifying things but perhaps you could answer a puzzle for me, don't want to interrupt the flow that is being achieved.

The thread indicates that the difference between 255K and current surface temperature can be explained by the time delay of movement of energy through the atmosphere. A denser atmosphere, longer delay, higher surface temperature and visa versa. My query is in regard to the reports a couple of years ago that the atmosphere was becoming less dense due to a quiet sun:


'The sun鈥檚 energy output declined to unusually low levels from 2007 to 2009, a particularly prolonged solar minimum during which there were virtually no sunspots or solar storms. During that same period of low solar activity, Earth鈥檚 thermosphere shrank more than at any time in the 43-year era of space exploration.
The thermosphere, which ranges in altitude from about 55 to more than 300 miles (90 to 500 kilometers), is a rarified layer of gas at the edge of space where the sun鈥檚 radiation first makes contact with Earth鈥檚 atmosphere. It typically cools and becomes less dense during low solar activity. But the magnitude of the density change during the recent solar minimum appeared to be about 30 percent greater than would have been expected by low solar activity.'

Would this not provide empirical data to test against?
Would the effect be noticeable in surface temperature after a delay time and what would that delay be, theoretically?

There wouldn't be a connection seen here:

#12. - Ian H wrote:
"How come the year 2007 did not make it into the top ten, with the solid two months of very heavy rain night and day, every single day. This caused devastating floods, particularly in the North and also in the South such as Tewkesbury."

As far as I can see, 2007 was the 16th wettest year, based on the 1910 series.
This is presumably due to the fact that while May-July were all relatively wet, the other months must have been relatively dry, although I haven't been through all of the months.

Personally I find it more informative to use the HadUKP data series, for which England & Wales figures start in 1766, than the more recent 1910 series.
Assuming average rainfall figures in December, the annual Engalnd & Wales figure will be 1166 mm, which would make it the 6th wettest year on record, after:
1872 = 1284.9mm
1768 = 1247.3mm
2000 = 1232.4mm
1852 = 1213.0mm
1960 = 1195.0mm
If rainfall is 6 mm below average in December, this year will also be lower than 1903, with 1160.3 mm.
Six of the top 10 years in this series were in the 18th or 19th centuries, i.e. before "climate change" allegedly began.
Again, assuming average rainfall for December, the 30 year average in 2012 will be 946.7mm, while the 30 year average in 1886 was 943.2 mm.
The 10 year ma will be 933 mm in 2012, but the 10 year ma exceeded 1000mm between 1880 and 1884.
As far as variability is concerned, the 30 year standard deviation will be 120.6mm but the 30 year sd in 1877 was 151.4 mm.
The 10 year sd will be 135.7mm in 2012, but it reached 167 in 1789 and was picture is different when you take a longer-term perspective.
This may be because the "natural cycles" have longer periods than are visible in the relatively short-term.

As QuaesoVeritas points out there have been significant runs of wet years in previous centuries. The Met Office artificially restricts itself to post-1910 whereas there are reasonable rainfall estimates for England that go back to the 18th Century. If we are going through a run of wet years now, there certainly was another run in the 1920s and, like QuaesoVeritas says, there was another series of very wet years that centred around the early 1880s. I have previously studied rainfall records in the East Midlands that show a strong peak around 1879/80 and in London 1878/79 - these were followed by runs of particularly dry years in the 1890s that would be comparable to the sorts of cycles we have seen in the last couple of decades. Indeed what I have seen appears to show that there is quite a variation in 'average' rainfall across various areas of England over periods of years. I don't see anything particularly different about our recent rainfall patterns.

#24. - Leedschris wrote:
"I have previously studied rainfall records in the East Midlands that show a strong peak around 1879/80 and in London 1878/79"

Thanks. Are the rainfall records you have studied from the Met. Office, or some other source?

ukpahonta,

You gave us this quote as regards the therosphere:

"It typically cools and becomes less dense during low solar activity"

That puzzles me because cooling and contraction usually increase density.

Could it be a typo ?

Thanks for your favourable comments.

#26

Stephen Wilde

From the same link:
'Their work built on several recent studies. Earlier this year, a team of scientists from the Naval Research Laboratory and George Mason University, measuring changes in satellite drag, estimated that the density of the thermosphere declined from 2007 to 2009 to about 30 percent less than during the previous solar minimum in 1996.'


A conundrum indeed, how could this be explained?

ukpahonta

Ah, I've come across that before.

They are just talking about the density at the height of the satellites.

They orbit at a high enough level such that when the thermosphere shrinks then density reduces at the level of the satellite.

However the density of the contracted thermosphere below the satellite is actually increasing.

Ukpahonta - possibly related/also worth a look.

#28 Stephen Wilde

That would explain it.

#29 lateintheday

Some good stuff at Tallblokes recently, impressed.

re 25 QuaesoVeritas

Yes, it's a few years back I did some work on this. The data for the East Midlands (Leicestershire) were taken from the British Rainfall series, updated by the then Monthly Weather Reports from the Met Office. For London the information could be found in the work by Brazell on a 'Century of London Weather'.