Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Uk Weather Predictability And The Effects Of The Jet-stream...


Robbie Garrett

Recommended Posts

Posted
  • Location: London, UK
  • Weather Preferences: MCC/MCS Thunderstorms
  • Location: London, UK

Moderators, I saw a very healthy discussion going on the model forums.. and will so paste those into here. Please edit the topic title as you wish.

Some thought provoking posts from PE & CC, but with respect probably better suited to the 'Climate & Environment' sub-forum, best to stick to the actual model output here....thanks smile.png

With all respect to your viewpoint, I dont agree with all you say! The British weather is not predictable, look at this April and compare it to last April. Chalk and Cheese come to mind. Yes youre right in saying that the last 5/6 years have seen somewhat familiar synoptics especially in Spring. But there is cycles within cycles and as yet, mankind/scientists have no idea what-so-ever to decifer the enourmous and extremely complex nature of the weather, we certainly can give our numerous ideas but clearly along with computer models outputs we have no idea! Back to the model output, and the weekend looks quite concerning at the moment with some big deluges in some places. The Devil in the Detail on this one!help.gif

Well put it this way, I'm not convinced that something isn't in the process of occurring; or at least in initiation phase. If it carries on, sooner or later someone is going to have to acknowledge the fact.

The issue is that we rely on crude data far too much which masks actual synoptics and patterns and the deviations/anomalies within these. We ridicule scientists for their predictions of climate in 50 years (even those who predict another ice age onset) but in reality and from my perspective, they aren't as outlandish as some people think.

Very good reply. There is more than a sinister pattern developing. Not only is the mid spring / season developing a pattern. We are seeing a trend of absurdly warm spells in March / early April and also similarly around the equinox in autumn - we recorded 30oC here on 2nd October last year !! It is a result of climate change - of that I am sure.. Climate change rather than global warming. Like you I think we need to look north for the reasons.. Could it be the copious amounts of water released into the North atlantic from melting ice ? Could it be warmer surface temps over the arctic supporting greater anticyclonic conditions above. It cannot just be down stream signals otherwise we'd have to look to the tropics for the cause. Something is also causing the jet to dive south from April / May until the end of August.. over the UK. I can't see how this can be sensationalist as the last 5 years have already happened so we are looking back rather than forecasting 5 years henceforth. What drives the adjustments to the flow of the jet in the northern hemisphere. why is it not tracking NE Over iceland and into Northern Norway as it used to do for weeks on end during summers from only 5-10 years ago. The thing of concern IS The fact the British weather is appearing to become predictable.. Something previously unheard of. If you look at all the models they all show the jet tracking northwards again over the next 10-20 days across central Europe and up to the SE of Finland and into Russia. Heat is already building in Russia and Ukraine. If this trend continues similar to last year, on a serious note we could see temps close to 40oC for the European Chamionships in Ukraine.. One to look out for !

I agree that the pattern over the last few years has been for pressure to build strongly out east giving places like Moscow record warmth. I have noticed myself that weather patterns have been repeating and persisiting for some time for a good while now. I have no idea what is causing it.....could be low solar activity or even as a result of climatic shift resulting in positive reinforecement/feedback of a certain weather type in certain geographical areas.

Still too early to comment on summer weather though as even within broad patterns, smaller pattern changes cannot be precluded.

I notice that it hasn't been given much recognition by certain members, possibly for fear of sounding 'out there' or sensationalist, but I have noticed it and IMO it's not normal. I have no scientific basis when I say this, but I get the impression that the building blocks for a southwards migration of the arctic tundra could be being laid. Something which my (very clued up) geography lecturer is convinced will occur within the next 50 years.

Some real concerns now that we could be heading for a record cool, dull and wet May. ECM out to +240 maintains the southern jet and the conveyor

belt of Low pressures across the UK. Although with a hint to a more mobile westerly regime towards the end of the run. Interestingly the MET O 6-15 and

16-30 paints a gloomy prospect out as far as a months time heading towards the Witsun week. What troubles me the most with what the models are painting

is an a repeat of the spring and summers of 2007 thru 2011. A trend of the modern summer seems to be this southerly tracking jet. A strong Russian High

which seems to set up residence for months, and a Greenie High which locks us into northerlies interchanging with lows on a southerly trajectory. Looking

back at the last 5 years the pattern established in May, seemed to repeat through the following three summer months bringing more traditional summers of

the seventies and eighties. Ironically March could end up being warmer than April and Maybe May.. ;oO.. There are no downwind signals to signify any major

pattern change.. The polar vortex has lost a lot of its seasonal strength. Useful rain to help abate the winter droughts, however for sun worshipers and crop

growers, concern to say the least. GFS is showing the first summer heat to be some 500 or so miles further east in the coming weeks..

Let's continue here.....

Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

The topic was briefly touched upon in the "In The News" thread last week. Here's one one paper to consider at least

http://www.deas.harv...sVavrus2012.pdf

"Arctic amplification (AA) – the observed enhanced

warming in high northern latitudes relative to the northern

hemisphere – is evident in lower-tropospheric temperatures

and in 1000-to-500 hPa thicknesses. Daily fields of 500 hPa

heights from the National Centers for Environmental Prediction

Reanalysis are analyzed over N. America and the

N. Atlantic to assess changes in north-south (Rossby) wave

characteristics associated with AA and the relaxation of poleward

thickness gradients. Two effects are identified that

each contribute to a slower eastward progression of Rossby

waves in the upper-level flow: 1) weakened zonal winds,

and 2) increased wave amplitude. These effects are particularly

evident in autumn and winter consistent with sea-ice

loss, but are also apparent in summer, possibly related to

earlier snow melt on high-latitude land. Slower progression

of upper-level waves would cause associated weather patterns

in mid-latitudes to be more persistent, which may lead

to an increased probability of extreme weather events that

result from prolonged conditions, such as drought, flooding,

cold spells, and heat waves."

Link to comment
Share on other sites

Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire

The topic was briefly touched upon in the "In The News" thread last week. Here's one one paper to consider at least

http://www.deas.harv...sVavrus2012.pdf

"Arctic amplification (AA) – the observed enhanced

warming in high northern latitudes relative to the northern

hemisphere – is evident in lower-tropospheric temperatures

and in 1000-to-500 hPa thicknesses. Daily fields of 500 hPa

heights from the National Centers for Environmental Prediction

Reanalysis are analyzed over N. America and the

N. Atlantic to assess changes in north-south (Rossby) wave

characteristics associated with AA and the relaxation of poleward

thickness gradients. Two effects are identified that

each contribute to a slower eastward progression of Rossby

waves in the upper-level flow: 1) weakened zonal winds,

and 2) increased wave amplitude. These effects are particularly

evident in autumn and winter consistent with sea-ice

loss, but are also apparent in summer, possibly related to

earlier snow melt on high-latitude land. Slower progression

of upper-level waves would cause associated weather patterns

in mid-latitudes to be more persistent, which may lead

to an increased probability of extreme weather events that

result from prolonged conditions, such as drought, flooding,

cold spells, and heat waves."

Very interesting, and similar to my thoughts. There is no doubt that we have been witnessing, over the past few years, what this paper is saying.

Link to comment
Share on other sites

Posted
  • Location: London, UK
  • Weather Preferences: MCC/MCS Thunderstorms
  • Location: London, UK

I take it these extremes are the weather trying to balance the climate out. I think the documentary 'Orbit' from the BBC touched on it, that the temperature change in the climate has made the weather go wild.

From Memory, nothing really stands out except... Summer 2003 (Maybe this was a natural occurrence and just pure luck of synoptics) and until really the cold winter periods we experienced, in 2009, 2010 + November/December 2010.

Summers have been cool in the past, and was this a result of the jetstream also diving south?? I personally presume so, without looking at the past jetstream charts (are they available??) and no exceptionally hot weather prevailed.

Thing we have to remember is that the April heatwave, and the late Autumn one we received may have been the climates way of dealing with things, or was it just luck with synoptics? I understand a few records were and have been broken, but only in the last few hundred years.

Personally, ever since November/December 2010 the weather has been very weird, probably because of how early in the winter it started off and probably hence why it lead to a cooler Summer, because it was part of the jetstreams pattern to head south (during Summer 2011) and obviously now it's South in Spring (unlike last year). Whereas winter it was the complete opposite in that it was northerly jetstream. If I can count my odds, Summer may see a northerly tracking jetstream, autumn a southerly and winter a northerly..... surely this a normal pattern??

Edited by Robbie Garrett
Link to comment
Share on other sites

Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

I've just posted another piece 'in the news' by prof Lovelock, A man, that I feel, bares listening to. We are in the process of 'change' driven by our outputs but the planet , Gaia, tries it's best to remain 'stable'. Cold drivers and low solar (IMHO) have helped 'slow' recent climate shift esp. rate of temp change globally. The Jets are tied in with this and their northerly progression has become 'stuck' leading to broadly similar pressure patterns ,at certain times of year, becoming common. Other changes (arctic sea ice) continue in their change at a pace unaffected.

I feel that 'natural cool drivers', driven by oceanic cycles, have been responsible for this 'slowdown' in climate shift but that some of them (low solar) are now flipping state. Once all drivers (PDO/ENSO etc) flip back to 'warm' then the rate of change will again pick up and the Jet will slip north leading to a serious climate shift for the temperate regions.

If we spend 2 months longer on the tropical side of the Jet then those 'snippets' of future climate (last Oct and late March this year) will become ever more the norm.

Edited by Gray-Wolf
Link to comment
Share on other sites

Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire

I've just posted another piece 'in the news' by prof Lovelock, A man, that I feel, bares listening to. We are in the process of 'change' driven by our outputs but the planet , Gaia, tries it's best to remain 'stable'. Cold drivers and low solar (IMHO) have helped 'slow' recent climate shift esp. rate of temp change globally. The Jets are tied in with this and their northerly progression has become 'stuck' leading to broadly similar pressure patterns ,at certain times of year, becoming common. Other changes (arctic sea ice) continue in their change at a pace unaffected.

I feel that 'natural cool drivers', driven by oceanic cycles, have been responsible for this 'slowdown' in climate shift but that some of them (low solar) are now flipping state. Once all drivers (PDO/ENSO etc) flip back to 'warm' then the rate of change will again pick up and the Jet will slip north leading to a serious climate shift for the temperate regions.

If we spend 2 months longer on the tropical side of the Jet then those 'snippets' of future climate (last Oct and late March this year) will become ever more the norm.

Whilst I see some merit in what you're saying, I fear that it's not as simple as 'we are going to get warmer'. I'm yet to be convinced that the NAD will not shut down as it thrives on the salinity of the north Atlantic. I'm also yet to be convinced that the recent solar state is not a taste of things to come. What happens if we get a prolonged very quiet sun and an NAD shut down? I do think we are guilty of being far too ethnocentric and simplistic when arguing the toss over climate change.

As for Lovelock, he has a very anthropomorphic view of the world and to be quite frank, the earth is not a living organism and has no conscience whatsoever. The drivers of climate are far far too complex for even the most powerful of computers to fathom.

Edited by CreweCold
Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

Whilst I see some merit in what you're saying, I fear that it's not as simple as 'we are going to get warmer'. I'm yet to be convinced that the NAD will not shut down as it thrives on the salinity of the north Atlantic. I'm also yet to be convinced that the recent solar state is not a taste of things to come. What happens if we get a prolonged very quiet sun and an NAD shut down? I do think we are guilty of being far too ethnocentric and simplistic when arguing the toss over climate change.

As for Lovelock, he has a very anthropomorphic view of the world and to be quite frank, the earth is not a living organism and has no conscience whatsoever. The drivers of climate are far far too complex for even the most powerful of computers to fathom.

Not sure if you've heard of this CC, but it could be your trigger mechanism for the NAD shutdown! http://www.esa.int/esaEO/SEMD7FNXDXG_index_0.html

Very difficult to predict what affects this may have if it spilt south though. While northern hemispheric weather patterns would certainly change along with cooling in the north Atlantic, global impacts may be more difficult to anticipate.

Link to comment
Share on other sites

Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire

Not sure if you've heard of this CC, but it could be your trigger mechanism for the NAD shutdown! http://www.esa.int/e...XG_index_0.html

Very difficult to predict what affects this may have if it spilt south though. While northern hemispheric weather patterns would certainly change along with cooling in the north Atlantic, global impacts may be more difficult to anticipate.

I'll have a read. I can't see a smooth ride into a mediterranean type climate though whatever happens.

A study into climatic change would be a very interesting topic for a PhD, I'm very tempted :p

Edited by CreweCold
Link to comment
Share on other sites

Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

A cooling world is far more frightening than a warming one (for us in the 'developed world') I think? As it is i fear our planet has absorbed far too much energy over the last 150yrs for 'cool down' to be on the cards?

We appear on the very edge of large CH4 emissions from tundra/submerged tundra and i think this will be the domino to topple a very large climate shift?

As for Gaia being somehow 'alive/conscious'? Nope, don't view it that way myself but do see a very honed and complex set of 'controls' in climate, both living and 'inert', that both aid and abet in any climate 'wobble' so that once any one driver is impacted others must try and minimize any 'rapid state shift'. Tip enough drivers and the same 'system' will also 'flip ' to the new equilibrium.

As such it is easy to 'Personalise' the process into a living thing doing it's best to keep on top of (regulate) a very complex system?

I cannot think of any process' I've witnessed in nature that was a 'smooth progression' when looked upon in the correct 'scale'.?

Edited by Gray-Wolf
Link to comment
Share on other sites

Posted
  • Location: London, UK
  • Weather Preferences: MCC/MCS Thunderstorms
  • Location: London, UK

Personally having just read some stuff on the internet, the idea of what has been said is that the planet will fight back because it in itself is alive.

For example, what does it do when it gets so hot and humid?? it thunders and absolutely chucks it down, ok that's not the whole story but what happens to the temperature?? it drops.

A valid explanation for the following? Why have the last 3-4 winters in the Northern Hemisphere been so deadly and widespread compared to 10-15 years ago when temperatures where likely to be cooler than they are today. Yes, we've had far more extremes in temperature rises, but there's all this science out there proving/disproving the hypothesis but there are no clear links between anything. It's all in my eyes propaganda.

Is there any link, or any scientific research or anything remotely that says by having heatwaves and extreme temperatures around the globe, then in the winter the climate tries to balance itself out and makes that average yearly temperature what it should be.

Link to comment
Share on other sites

Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

Or it could all just be weather doing what it does, as it's always done.

Here's a pretty good site for historical weather, it takes a while to look through all the eras covered but what becomes very clear is that weather in this country has often gone through phases. There are periods where hot summers follow one after the other for a few years, and periods where cold winters follow one after the other for a few years; groups of wet years and groups of dry ones. Groups of warm ones and groups of cold ones.

http://booty.org.uk/booty.weather/climate/histclimat.htm

Also, of importance is the Lockwood paper linking and showing causal effect of the impact of quiet Solar periods on NH weather patterns - we're still going through a quiet Solar period, as we have been for the same time period as the jetstream has been taking an alternative route than we usually expect. Coincidence? Perhaps. But a pretty good match time wise for the changes seen.

We happen to be personally experiencing the current weather, we also happen to know we've pumped a lot of CO2 out over the years - that doesn't however make it unique nor a foregone conclusion that the two are inextricably linked.

Link to comment
Share on other sites

Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

Or it could all just be weather doing what it does, as it's always done.

Here's a pretty good site for historical weather, it takes a while to look through all the eras covered but what becomes very clear is that weather in this country has often gone through phases. There are periods where hot summers follow one after the other for a few years, and periods where cold winters follow one after the other for a few years; groups of wet years and groups of dry ones. Groups of warm ones and groups of cold ones.

http://booty.org.uk/.../histclimat.htm

Also, of importance is the Lockwood paper linking and showing causal effect of the impact of quiet Solar periods on NH weather patterns - we're still going through a quiet Solar period, as we have been for the same time period as the jet stream has been taking an alternative route than we usually expect. Coincidence? Perhaps. But a pretty good match time wise for the changes seen.

We happen to be personally experiencing the current weather, we also happen to know we've pumped a lot of CO2 out over the years - that doesn't however make it unique nor a foregone conclusion that the two are inextricably linked.

Well it has naff timing as far as the Arctic is concerned then? Fancy this 'odd pattern' choosing to occur with ice at such perilously low levels?

If open water Arctic is tied into the upper atmosphere circulation (as per the paper BFTV posted above) then a record low year there is not good for those hankering after a return to earths old weather 'patterns'?

Edited by jethro
There's a dedicated thread for ice discussion, please stay on topic.
Link to comment
Share on other sites

Posted
  • Location: Rochester, Kent
  • Location: Rochester, Kent

I've just posted another piece 'in the news' by prof Lovelock, A man, that I feel, bares listening to.

Most of the time I prefer to read fully clothed.

Weather is unpredictable, but climate generally is. This is a basic tenet?

Fancy this 'odd pattern' choosing to occur with ice at such perilously low levels?

If open water Arctic is tied into the upper atmosphere circulation (as per the paper BFTV posted above) then a record low year there is not good for those hankering after a return to earths old weather 'patterns'?

Who says it's 'perilously' low? It's been this low before - indeed it's been lower; I don't think the ecosystem cares much for such negative platitudes.

Link to comment
Share on other sites

Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

Who says it's 'perilously' low? It's been this low before - indeed it's been lower;

.

Unless we are looking beyond the last ice age I think I'd need to see your hand on this boar old bean?

I have seen no accounts of the whole basin having ice of 5yrs and younger? Remember that ,with the onset of aviation, many new Arctic Islands were discovered only to be found to be massive floes of MY , Paleocryistic ice (probably some of Ward Hunt mixed amongst them!) Cold war bases were apparently placed on these 'ice islands and Radar checked their positions as they traveled the basin until their final disintegration.

Looking at the North shore of Greenland/C.A. I find it difficult to imagine any such ice growth under current climate conditions and in fact I see ,year on year ,a drain of this ice from the basin, now the shore bound ice on the North greenland Shore has retreated, leaving clear passage to Fram.

To me this year looks likely to break the record low ice extent set by the freakish 'perfect storm' of 07'. Thin ice and a resumption of ice export from the basin look set to leave us with an ice free pole and a record low extent?

Should current conditions remain 'stuck' it will be another summer here of constant L.P.'s and showers and another Russian Drought/heatwave (another 1 in 100yr event) with large amounts of ice flowing through Fram.

Both the NW passage (now all FY ice) and the northern passage will be open again (another event that whalers/fishermen would not have missed over the past 3 centuries) meaning another warm year for the submerged permafrost of Siberia.(which is only now degrading with no evidence of the same occurring since it was submerged at the end of the last ice age???)

As I've said it would be nice to see a few studies showing basin wide ice retreat with the total loss of the paleocryistic ice type?

Edited by Gray-Wolf
Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

Who says it's 'perilously' low? It's been this low before - indeed it's been lower; I don't think the ecosystem cares much for such negative platitudes.

Perhaps perilously low indicates that it wouldn't take much for the Arctic sea ice to become seasonal. Whilst you may not agree on the significance of this, the nitpicking and insults really aren't necessary.

Link to comment
Share on other sites

Posted
  • Location: Rochester, Kent
  • Location: Rochester, Kent

Perhaps perilously low indicates that it wouldn't take much for the Arctic sea ice to become seasonal. Whilst you may not agree on the significance of this, the nitpicking and insults really aren't necessary.

Not nickpicking, BFTV. Assigning platitudes to each and every negative phrase or event in climatology (ie impinging doom and disaster) is, frankly, spin-doctoring. If you find it insulting that I prefer not to read spin, rather facts and figures, then that is a matter for you. I mean, come on, using the word 'perilously' is really dragging the bottom of the barrel don't you think?

Edited by Boar Wrinklestorm
Link to comment
Share on other sites

Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

This is a shiny new thread for exploring the issue of how, why or if the weather has changed in recent years. It isn't an opportunity to cover the same old ground with the same old stuff; if you want to discuss the Arctic, there is a dedicated thread for ice discussion, please take this conversation over there.

Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

The Arctic sea ice variation can and will have a strong influence on mid latitude weather patterns, especially if it becomes seasonal. An associated change in our climate could then feasibly occur.

Dragging the bottom of the barrel... only if you think none of this matters, which would also be just a perspective.

Edited by jethro
Off topic.
Link to comment
Share on other sites

Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

I'm sorry J' but ,as the paper BFTV linked to shows us, the Arctic is very much in the frame for influencing the changes some folk are now noting in our 'stuck/odd ' weather patterns.

With folk using terms like 'Air conditioner of the world' to describe the impacts of the Arctic's sea ice how could we possibly disscuss alterations to atmospheric circulation patterns without including such a major contributor to such changes? (surely just changes in Albedo has it's impacts never mind the huge wodge of energy that the warmed 'open water', now present in the high Arctic at the end of melt season, posses come late Sept?)

Edited by Gray-Wolf
Link to comment
Share on other sites

Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

I'm sorry J' but ,as the paper BFTV linked to shows us, the Arctic is very much in the frame for influencing the changes some folk are now noting in our 'stuck/odd ' weather patterns.

With folk using terms like 'Air conditioner of the world' to describe the impacts of the Arctic's sea ice how could we possibly disscuss alterations to atmospheric circulation patterns without including such a major contributor to such changes? (surely just changes in Albedo has it's impacts never mind the huge wodge of energy that the warmed 'open water', now present in the high Arctic at the end of melt season, posses come late Sept?)

Discussing the issue of weather in association with the Arctic is one thing, using this thread as an excuse to beat the same drum about the state of the ice is another thing entirely.

Link to comment
Share on other sites

Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

For those who are pretty much convinced that the weather patterns over the last 3 or 4 years are indicative of what we can expect from climate change or are in some way a symptom of it.....

Both Strattos Ferric and Ian Brown postulated endlessly that we would no longer have any cold winters, that snow was a thing of the past and that we had entered the period of 'even larger teapot' brought about by climate change. They stuck to their views and used the previous however many winters it was, to validate and support their view. They were wrong. They jumped the gun. They took a few years of weather and extrapolated it into the future.

Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

For those who are pretty much convinced that the weather patterns over the last 3 or 4 years are indicative of what we can expect from climate change or are in some way a symptom of it.....

Both Strattos Ferric and Ian Brown postulated endlessly that we would no longer have any cold winters, that snow was a thing of the past and that we had entered the period of 'large teapot' brought about by climate change. They stuck to their views and used the previous however many winters it was, to validate and support their view. They were wrong. They jumped the gun. They took a few years of weather and extrapolated it into the future.

Only that is not what's happening now. There is a clear and proven relationship (as shown in the paper posted earlier) between warming in the Arctic and changes in the pressure heights and thus the thickness gradient between the 90N and the equator. This isn't speculation based on the last few years but instead, based on a very sound scientific foundation and observed evidence of upper atmospheric changes.

Debating the causing of this Arctic warming is one thing, but questioning whether or not these changes can influence mid latitude weather seems somewhat behind the times, considering the evidence.

Link to comment
Share on other sites

Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

Only that is not what's happening now. There is a clear and proven relationship (as shown in the paper posted earlier) between warming in the Arctic and changes in the pressure heights and thus the thickness gradient between the 90N and the equator. This isn't speculation based on the last few years but instead, based on a very sound scientific foundation and observed evidence of upper atmospheric changes.

Debating the causing of this Arctic warming is one thing, but questioning whether or not these changes can influence mid latitude weather seems somewhat behind the times, considering the evidence.

And there were papers supporting the idea that the jetstream had moved northwards and that the expanding Hadley cell (as a consequence of global warming) was responsible for the warm winters we were experiencing. There are reams of them : http://scholar.google.co.uk/scholar?start=0&q=hadley+cell+climate+change&hl=en&as_sdt=0,5&as_vis=1

No one thing controls our climate or our weather, focussing purely on one, especially because it's the latest idea is IMO daft. One paper doesn't re-write climatology or meteorology; everything has to be taken into account, including the fact that sometimes we genuinely do just experience a few years of similar weather and it's not indicative of anything meaningful. The endless postulating about our "Modern Winters" should demonstrate that.

Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

And there were papers supporting the idea that the jetstream had moved northwards and that the expanding Hadley cell (as a consequence of global warming) was responsible for the warm winters we were experiencing. There are reams of them : http://scholar.googl...dt=0,5&as_vis=1

No one thing controls our climate or our weather, focussing purely on one, especially because it's the latest idea is IMO daft. One paper doesn't re-write climatology or meteorology; everything has to be taken into account, including the fact that sometimes we genuinely do just experience a few years of similar weather and it's not indicative of anything meaningful. The endless postulating about our "Modern Winters" should demonstrate that.

At no point have I endorsed the "Modern Winters" views of either Ian Brown or Stratos Ferric, their ideas were flawed, as I pointed out in the last post "This isn't speculation based on the last few years" - apologies if that wasn't clear

I've also never said that any one thing controls our weather.

Neither have I said that the paper I posted nullifies older studies in anyway. Those are straw man arguments.

The rapid warming of the Arctic has a clear influence on our weather and yes, it is but one of numerous factors that does so. Plenty of other drivers and variables will act to keep the weather quite changeable on a large scale. Nobody is claiming that Arctic warming is the dominant factor in our weather, but it has been demonstrated to be a contributing factor all the same.

Edited by BornFromTheVoid
Link to comment
Share on other sites

Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

snapback.pngCreweCold, on 23 April 2012 - 19:15 , said:

I agree that the pattern over the last few years has been for pressure to build strongly out east giving places like Moscow record warmth. I have noticed myself that weather patterns have been repeating and persisiting for some time for a good while now. I have no idea what is causing it.....could be low solar activity or even as a result of climatic shift resulting in positive reinforecement/feedback of a certain weather type in certain geographical areas.

Still too early to comment on summer weather though as even within broad patterns, smaller pattern changes cannot be precluded.

I notice that it hasn't been given much recognition by certain members, possibly for fear of sounding 'out there' or sensationalist, but I have noticed it and IMO it's not normal. I have no scientific basis when I say this, but I get the impression that the building blocks for a southwards migration of the arctic tundra could be being laid. Something which my (very clued up) geography lecturer is convinced will occur within the next 50 years.

I noticed there had not been much discussion on this forum of the many recent papers on this subject. The scientists are puzzled too - hence the variety of theories that have been postulated. It has been agreed that a new circulation pattern has been in evidence over the last few years - cause attributed variously to Arctic ice loss and/or changes in solar output. Most of these papers have considered the causes of recent cold winters across the NH. Not seen much about the summers as yet but it is the same pattern that causes both; dubbed as the Arctic Dipole Anomaly or warm Arctic, cold continents anomaly there is plenty to be found with a Google search.

Regarding the comments on shutdown/weakening of the NAD; recent winter patterns have shown us that we can experience truly frigid conditions in western Europe while the NAD goes about it's business as usual. Depriving the landmass of the benign influence of westerly winds and substituting an mP or cP airmass is all that is necessary.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    More rain on the way: Storm Nelson brings gales Thursday, but rain and wind easing for Easter

    Spells of rain or showers with sunshine in between affecting most areas today, snow over northern hills. Storm Nelson arrives tomorrow, bringing gales to southern coasts and windy elsewhere with further showers. Showers and wind easing somewhat into the Easter Weekend. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-27 09:35:27 Valid: 27/03/2024 0900 - 28/03/2024 0600 THUNDERSTORM WATCH - WEDS 27 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...