SMU

1).- Lets be clear- Lower pressure than average means LESS of an infleunce- A handful of millibars should NOT be catagorised as unimportant.... 2)-. there has only been one summer month- JUNE- ( However July is pretty much of the same vein) 3)- Balony- If an area has LOWER than usual pressure observed you cannot then assert that it has had a wider influence - thats just pure nonsence & has no credibililty- the azores high isnt a block of blue tac- The anomaly map from Philip Eden provides for June http://www.climate-uk.com/monpre/0606.htm Shows the azores high has been displaced NORTH not EAST- the flow is Meridional NOT zonal- All the while the hot air in june was pushing NW from France you HAVE to draw the conclusion that there is lower Pressure towards the azores Flanking the Continental High 4) Nonsence again- You have NOTHINg to back this statement up- 5) yes occasionally it has- but then is it expected to now & again- West, we all here understand that for some reason you have a deep routed love of the azores high- however you should be more subjective when looking at the information provided- To date you have yet to provide anything Factual ( whether that be Pictorial or Statistical) that back up your claims- S PS west- this is an anomaly pattern you want from the azores- http://www.climate-uk.com/monpre/0508.htm

Philip also does seasonal- http://www.climate-uk.com/monpre/06QQ.htm Interesting winter just passed- very out of kilter with recent form........ S

Yes My bad Enforcer- Pressure anomalies against the norm- thats why sometimes i get annoyed with people who preach that a month/season was dominated by a certain high pressure cell- but dont have the stats to back it up- Philip Eden creates an MSLP anomaly map for the month which we can use to varify- http://www.climate-uk.com/monpre/0606.htm The box on the top right is the anomalies for June- as you can see the picture tells the story of the summer so far.... Pressure belt anomaly over Central Europe forcing the Jet further North into Greenland and pumping the Hot air NW- NB: Lower than usual observed pressure over the azores- Sadly some people really do deliberatly overlook these when they really are Gospel- S

Hi John - The problem here is ALL entities are using different recording/validation methods- This then becomes a pigs ear when trying to varify any one particular forecast- Considering its the hardest Teleconnection to forecast then I think at least for now the MSLP anomalies rather than the NAO are the way forwards in giving us a tool to forecast at a seasonal level- The weather which arrives via those pressure anomalies is 'generally' forecastable from that perspective- especially when referring to seasonal parameters such as temperature & rainfall- S

Just reading between the few posts here & picking out the messages about the NAO- Im very interested to know where the Met office import the data from to get an Negative NAO'd Winter- Clearly the NOAA (CPC) historic shows Positive for 05/06 Winter- http://www.cpc.noaa.gov/products/precip/CW...ent.ascii.table I guess the differences were the point of measurements..... From my perspective whoever & whatever the measurement was there wasnt any pronounced negativity until March- this is also backed up by the NE US +ve temp anomaly & Philip Edens MSLP Anomalies for the same period- Dec 05- http://www.climate-uk.com/monpre/0512.htm neutral ( anomalies wise ) Jan 06- http://www.climate-uk.com/monpre/0601.htm Must be 100% pos Nao.. So then just to Clarify- Met office ACTUAL forecast- Good & well Called- NAO forecast/Model - Wrong to call negative despite the Metoffice claiming it was negative-Never read that information before & I despute it- Perhaps they use Tom osbourn whoever he is- http://www.cru.uea.ac.uk/~timo/projpages/nao_update.htm Still cant believe JAn was Negative- What a crock- S

I do agree that the METO forecast was good & at a level managable with the current knowledge in the field of LRF's- in terms of not over diluting the forecast- but keeping it simple with 2 parameters- What does stick in my mind to enhance their accuracy was the European forecast in terms of it being well below ave- this turned out equally accurate- The NAO output was however called incorrectly- the Call for negative was wrong, it was a Positive Winter- Interestingly as I mentioned earlier If they are basing this Winter on the NEwfoundland SSTA's then the forecast will most definatly be for a POS NAO winter- Whether they will elude to any other estimates based on this one measure is very unlikely- but this should give the Meto Winter seasonal forecast a steer to mild - Whether we agree especially with the alleged changing of patterns ever lurking in the background is another matter- Good discussion points though- S

LOL- Flamed from the continental high......... I just dont see the point of coming in & contributing to a thread without anything of substance around the topic..... S

yawn- glass half empty as usual- If it was such a fruitless task then bodies like the NOAA wouldnt be investing countless millions of dollars in Seasonal forecasting- Sure, detail isnt the main emphasis- but that doesnt stop the field moving forwards- If we all took the approach of it will never happen or cant happen i wouldnt be writing on this keyboard looking at TV- They said the world was flat until it was challenged........- You do know the world is round SF- ?? yes West.... but it is a bit of a stuck record......... With SF's unquestionable knowledge it could be better served than that.... In current LRF terms for the winter the only element to go on at the moment in term of a forecasting tool ( if you take aside the alleged pattern change) are the positive SST's across newfoundland- these generally contribute to a + nao winter..... S

Philip edens flow pattern anomalies for July: http://www.climate-uk.com/monpre/0606.htm My call was- In terms of MSLP Anomalies the headlines are- Central & Northern Europe Substantually greater than Normal especially for the second half- Greenland Higher than ususal- Azores Lower than usual Very pleased however the Greenland call was wrong- Regional variations- http://www.climate-uk.com/monthly/0606.htm Rainfall exceptionally low- lower than I predicted- S

No- My E&W Summer CET was estimated at 15.9C - However because of the migration of the polar front a little earlier than expected that may have to amended to 16.3C..... & Seasonal rainfall average maybe to 40% S

Evening All- As June draws to a close I though I would add a post into my Summer outlook Thread- I think the summary for June is that the month has been Very close to the forecast & has actually exceeded expectations in terms of Temperature Anomaly & Lack of Rainfall- With the transitory Polar front phase arriving at the end of May rather than the start of June we saw summer kick in with a high pressure cell that Covered the whole of Central & Northern Europe- The best representation of this is the fax chart for the 8th of June- Now refer to the Summer forecast Headlines- Central & Northern Europe MSLP anomalies Substantually greater than Normal especially for the second half Reduced frequency of frontal rainfall across the UK ESPECIALLY FOR THE NORTH & NORTH WEST Flow Patterns are set to be MERIDIONAL throughout the Summer NOT ZONAL ( this is after a transitory phase at the start of Summer) I cant wait for the Climatology to arrive from Philip Eden- Anyway Im not claiming Success yet- however I have kept 'touting' the big Continental high this year at the expense & Preference of the azores high- & as we welcome July look whats sat slap bang on our doorstep- http://www.wetterzentrale.de/pics/Rtavn721.png A perfect continentla flow pushing temps towards 90F- with LOWISH RH levels a Perfect Summer- Hopefully this Summer reflects my thoughts throughout & I can move onto a more successful Winter forecast- Best regards Steve

Hi Paul- Some interesting thoughts there- I agree with LRF's being in there infancy- Anyone who tries to pinpoint a specific event 6/12 weeks of so in the future is foolish- The only way forward and something thats been mentioned by Myself & GP/SP a few times is to use the statistical global data from the teleconnections- These are indicators of how the upper Atmosphere & Ocean temps are influencing circulation patterns- Then try to correlate these back to some form of broad forecast for a season- Its hazardous to say the least- especially as the dataset for teleconnections only goes back 50 years or so- Im sticking with the Summer forecast presented, The slow start in terms of temps & above average rainfall has actually been & gone throughout the end of May with the significant rains- I was expecting this period to be 2/3 weeks later into June- Never the less its gone, and now the pattern has broke and AS expected the dry conditions are set to prevail, with that first continental high lined up for the weekend- Hot, Sunny, Dry will be the watch words of this Summer with the torrential downpours distorting the overall rainfall patterns- lots of window watching to be had this year..... S

A Great Summer Forecast matey- Covering All aspects- Im at work & will have to have a more comprehensive read when People arent looking over My shoulder.... Anyway, with posts like that it shows how far we/us/all things.... have advanced even in such a short period of time... Whether the actual forecast comes off is still a mystery, however one thing is very true- Our basic assumption that due to continual global warming, the lower level forcing of the Troposphere & cyclical variabililty of the Stratosphere is & will lead to dramatic Climatological changes that in Some regions may not be reversabal... The most noticable for us being the Higher amplificational patterns in particularly the Winter with a displaced polar cell.... The sad part though is that eventually the polar cell may not be cold enough to support anything Wintry South of 50N..... Best regards & congrats once again.... Steve

Hi John- It was mainly for England & Wales..... With Ireland its important that the jet goes as far north as Possible so the atlantic activity is swept up towards iceland- FWIW I think after June you will be Ok Especially if you can pick up those SSE winds...... Best regards John... Steve

http://www.jisao.washington.edu/pdo/ http://www.jisao.washington.edu/data_sets/qbo/

Cheers Nick- I deliberatly didnt read either ians or the METO's until I produced mine- that way I can say hand on heart it was what I forecast- Glad to see were all on a similar wavelength.......... S

I think the PDO came out at +5 for April- Plus the QBO is now Westerly - Oh for it to stay like that for Winter.... S

Cheers All- GP when you posting your forecast??? Holding out for that last bit of data..??? S

Afternoon All- This is the second Seasonal forecast I have Issued & covers the Period June to the End of August. Having been reasonably happy with Winters effort I am this time covering a similar theme in the outlook. Also I have taken into Consideration the Seasonal effetcs of the SST's this year & the associated teleconnections However I know my colleague Glacier Point is preparing a more in depth view of these & it would be unfair to present a lot of material that he is going to be using ( needless to say my informed forecast is based around the same thing & therefor we 'should' come out with a similar type post) What I wont be doing is making the same mistake as before- which is forecasting anomalies Month by Month- In my humble opinion the details & conclusions to be made covering a seasonal forecast cannot be drilled down that far- This is where the MET office proved quite successful covering Winter- they just used 2 base parameters & stuck to them- these being- 1) Temperature departure from the Norm ( & a comparison against a historic year) 2) Rainfall departure from the Norm So in my Summary at the end I will use these 2 variables to measure the forecast with an estimated Summer E&W CET as well- I suppose before we get to any nitty gritty we need to know what the breakdown of the norm is & a good starting point is what controls our weather during the Summer Months- Firstly knowing the EXPECTED location of the Polar front is Key- It should circum-navigate the 60N line - This is the boundary between the Polar cell & Ferrell cell and where this boundary sets up is Crucial- One further note to this in which many woodbe forecasters over look is the type of high pressures that develop are correlated to the type of flow pattern being observed along the boundary between these cells. In a 'Typical' year with a West-East flow being fairly un-inhibited the High pressures that develop are flat in Nature & ridge East- A good example of this would be the Bermuda/Azores high ridging along the Lattitude. However in years where the Polar cell is persistent ( Another expression of this is seeing a negative AO) we often see large ungulations along the polar front- These years often ones with LOW sunspot activity see the uniform path of the path of the PF somewhat disturbed and providing large regions of exceptional static weather- In these instances High pressure Cells are rather circular & Ridge North South rather than east west. These also known as highly blocked/Meridional flows. Now were aware of the starting point of any summer we need to gather our thoughts in respect to the proposed positioning of our High pressure belts- Again it must be emphasised that the difference between the Polar front locale of 60N as opposed to 50N is the difference between a potential hot Summer & Cold unsettled one- And the evidence we should use is the Cycle of Patterns/Feedbacks as we approach Summer- this is because with any entry to a season ESPECIALLY at the start the type of pattern that is feeding back is likely to be sustained at least for the first portion ( this is the same as Winter- get into a cold pattern at the start & this can repeat throughout) However before we do that lets just remind ourselves of the 3/4 major high pressure players in Summer ( The reason I write 3/4 is because the Scandi High creates almost the Same type flow as the Bartlett in Summer ) The greenland High- This feature 'Should' NOT be a player in the Summers weather, this is because as the polar front gradually retreats North during Late Spring & Early Summer the Jet stream should Naturally pass through the Greenland region keeping pressure there generally LOW- If this doesnt occur & the polar cell stays strong the jet Stream will be Squeezed further South towards the 50N line- Heres what you DONT want to see in JUNE.... http://www.wetterzentrale.de/archive/ra/19...00119910603.gif http://www.wetterzentrale.de/archive/ra/19...00119910614.gif Final June 91 E&W CET was 11.7C thats 1.8C below the 61/90 Norm - This was attributed to Greenland blocking pushing the Jet south of the Uk or allowing it to Straddle, 1987 was very similar as well- The Azores high- This is a feature that is often touted as the most important thing to a Summer- but its a Misconception really- Unless the jet is riding at 60N or above then its often unhelpful- http://www.wetterzentrale.de/archive/ra/19...00119830703.gif http://www.wetterzentrale.de/archive/ra/19...00119830721.gif http://www.wetterzentrale.de/archive/ra/19...00119830729.gif Final July 83 E&W CET 18.6C thats 3.2C above the 61/90 Norm. This was the azores high at its best- with perpetual ridges being thrown East towards Scandi..... What a month. The problem I have the azores high this year is that the flow patterns, AO behaviour & Sunspot activity are not at all condusive to that type of set up- Also with the azores high often comes tropical air which is more often than not suturated ( VERY high humidity levels) which means we all feel uncomfortable.... The AZORES high on its own is NOT a prerequisite for a Good summer.... Finally The Scandi/ European High- In my opinion the best Summer the UK has had is the much vounted 1976, I 'Think' It was the last offical drought & it gave us brits a taste of what continental air/weather was all about- The best type of high is the one that drags ANY heat of a DRY origin, this can come via spain or indeed the heart of europe- 1976 was punctuated by this type of flow- August more Particularly... http://www.wetterzentrale.de/archive/ra/19...00119760702.gif http://www.wetterzentrale.de/archive/ra/19...00119760810.gif http://www.wetterzentrale.de/archive/ra/19...00119760814.gif http://www.wetterzentrale.de/archive/ra/19...00119760821.gif http://www.wetterzentrale.de/archive/ra/19...00119760825.gif The Final SUMMER 76 E&W CET was 16.86 thats 2.14C above normal- ( beating 1995).... So we now in place an idea of the 3 Key players for the Summer- Here would be my forecast & headlines on the 3 months June through August- The headline I suppose of the bat would be that record 'BREAKING' heat this year may be a little out of reach- the early indicators of substantial early heat building from a deep & stable Azores high are not in evidence so my first headline would be- No 100F recorded this Summer in the UK- With the recent patterns I have seen in the global atmospheric patterns the jet stream is Anything but strong so....- Flow Patterns are set to be MERIDIONAL throughout the Summer NOT ZONAL ( this is after a transitory phase at the start of Summer) The correlation I make with Meridional flows is that Frontal rainfall events become fewer & further between so- Reduced frequency of frontal rainfall across the UK ESPECIALLY FOR THE NORTH & NORTH WEST The Jet stream activity looks to be awfully slow so we are in for lots of Split jets which will be good for us especially in the second portion of Summer- Split jet running ABOVE 60N & south of 45N Should allow for the UK to sit in the dry slot- In terms of MSLP Anomalies the headlines are- Greenland Higher than ususal- Azores Lower than usual Central & Northern Europe Substantually greater than Normal especially for the second half- To put a comment & some figures on The 2 base parameters which I mentioned at the start are as follows- Temperature This Summer will be punctuated by a Slow first third in terms of building Warmth & by a polar front that is making its migratory journey later than ususal- However the remaining thirds should see this late start overturned by a VERY settled Period with consistent warmth/heat rather than Stiffling Heat- The estimated E&W CET is 15.9C which is 1.2C ABOVE the E&W seasonal average- comparison year- 1997 ( SUMMER ONLY) Rainfall This Summer im afraid looks like being another dry affair- The word arid does spring to Mind- but not quite.... The domination especialy in the second portion of the European high will see perpetual splitting of the jet & minimal frontal incursions- The Estimated E&W rainfall is 60% of the season average ( A word on rainfall - Whilst the OVERALL pattern looks dry from a frontal point of view I am expecting increased incidence of Convective type rainfall to occur which could disproportionate local accumulations-) Anyway I think that just about covers things... Best regards Steve :blink:

Not Forgetting Vince This Last october seen on the bottom Left.... Steve

Another below average month for me- ~ 6.4C A cold first half / warmer second........ similar to March- S

Thanks BFTP- Some good comments already- from the usual Sources etc- Looking forwards to further contributions from you & the likes of the forecasting team / Gp et al' S PS Rollo- perhaps your heaviest snow to come this weekend....

Morning All- thanks for th replies so far- Noggin- we may well have started a change prior to my dates- Feb 04 looks very much 'in sink' with the last 2 Febuary's http://www.climate-uk.com/monpre/0402.htm S

Good Morning- Im aware that there is a seperate thread running concurrent- so If admin feel this clogs the forum up to much then feel free to move it- There is however a lot of different things covered- Firstly- As we have seen out the last 'meteorlogical' days of Winter Ive tried to put together some information on what this Winter has delivered- but more importantly where I think it stands in terms of things moving through the next few years- We have seen the Phrase 'even larger teapot' used frequently over the past Season- and whilst Im sure that it did have a definitive meaning a few years ago I think now we are actually moving away from the Post 88 era which was dominated by the evervesent Westerly flow- The assumption here was that the UK could not sustain any form of cold spell due to the persistence of the Icelandic Low & Azores high- & there is definate data to support that.. Although Winter 04/05 could now POSSIBLY be defined as the POST even larger teapot- Anyway... This was my first Season preparing a Winter forecast,Ive provided the link should people still wish to browse http://www.net-weather.co.uk/forum/index.p...opic=26623&st=0 To a degree though Im very pleased of the outcomes in terms of 1) Precipitation - being on the Lower than seasonal average 2) Cyclonic Behaviour- Being in a convoluted state ( Higher frequency of blocking) 3) Overall Temperature- I wasnt quite right there- as it has turned out on the average mark- but below for england & wales- Next year I intend to produce another Winter forecast However there will be NO attempt to pin down Monthly CET- it will be based on the 3 Primary factors above at a Seasonal Level- I doubt there is the skill from anyone to drill forecasts down to the week despite having a wealth of information at our finger tips- The discussion as we entered the latter part of November- and often throughout the year was for evidence of so called 'pattern change'across NW europe- This was away from the westerly norm towards a more blocked scenario- What we couldnt pinpoint was the route cause if any could be attributed for driving a change in Synoptics- Indeed was it just a mirage- or could it be attributed to- The NAO Cyclical Shift?? Global Warmings influence?? Reduced Sunspot Activity?? SST Patterns?? Other?? Speculation has been endless- Although now With the Heinsite we can begin to say with further tentative evidence that we are moving away from the atlantic dominated Winters of the past 17 years- However a cautionary note- We have a dataset of evidence that covers only 2 years of possible 'change'- This means even with the magnitude of evidence that could be provided in favour of the new 'norm' it may still be a rogue or anomaly in the otherwise relentless warm up- Personally I think that it is an amalgamation of all the Teleconnection patterns ( & a few others ) that are beginning to conspire against the omni-present Icelandic Low & azores/Bartlett Highs- A few things immeadiatly strike me off the 'bat' Ask yourself these questions- How many Azores &/or Bartletts have lasted longer than a week since Mid November??- You would be hard pushed to find any.... How many Warm inversions have we seen this Winter??- Zero How many Cold Inversions have we seen this Winter-?? 2 significant ones- ( some may argue that a cold inversion isnt important- however I disagree as you need a cold high in place to deliver that cold inversion- & indeed the second one brough Snowfall in 850 temperatures of some +5 degrees 850 HPA) What about recorded Maxima this Winter- Some stations reporting NOT seeing a surface temp of above 10C for the WHOLE winter- Refer to Dave J's post for this info- We can also attribute the Colder CET's to lower night time minima- The higher incidence of Frost in all regions has been noticable- with I think the lowest recorded minima this last week of -19C ( un-official from Weather online) Those were just some of the things that spring to mind without much thought- The Key though is to see whats driving this-?? At the top of my list this Winter I would certainly put the Stratospheric air temps- especially at the pole as the big single factor of redundancy of the Westerlies- The basic assumption ( which is well documented) has the COLDER the Stratospheric gas the 'faster' the Artic & polar jet will flow due to the Stronger polar vortex- The winters of the 90's has some of the Coldest Stratospheric temps bringing in some of the Mildest CET returns- Ive attached a segment of work done on this Correclation between Warmer Stratospheric temps & Higher Pressure blocking- ( Compliments Typhoon tip NE US WX) Noticably the S.GAS has been remarkably warmer this year, this has been reflected well at higher lattitudes by the weakened vortex & higher heights observed at the poles- The Easiest way of having a snapshot of the height situation over the pole is to observe the AO ( Artic oscillation)- Strongly Positive correlates to A fast flow & strong vortex- a Negative AO is the inverse of that. As we can see from the Attachment the 'negativity' of the AO has been very Negative this Winter - So much so that since recording of the AO began in 1950, December had the Third most 'negative' reading- http://www.cpc.ncep.noaa.gov/products/prec...ent.ascii.table This however DOESNT Correlate to blocking to the North of the UK- its more a reflection on the global Mean Pressure patterns and shows how convoluted the Jet stream is- Again the correlation there is - Strong -AO = Convoluted Jet stream- We can continue the Stratospheric Gas temps through out this year with the zonal Mean temps at 50Mb at various Lattitudes- Already at the start of 2006 we can see the Warmer start to the year from a lattitude 65N- up to 75N- Now look at how cold 1990 was at the same time- As we can see there is some 25 degree difference between 1990 & 2006 between 60 & 75N- There is an approximate 25 day propergation wave delay in the Stratospheric gas temp change & the observed change in Surface Patterns- You would expect that the AO>NAO Link would come into the equation here- but the NAO has been ( And always will be) the wild card here- There is a linear correlation with the negative AO Phase of about 0.6 to a Negative NAO phase- ( 1 being a total correlation & -1 having no effect what so ever) - Sadly for this Winter the Mean AO pressure anomaly delivering the 'negative' goods has been in situ over the Pacific or the far east- meaning that for this Winter the 0.4 part of the correlation has been demonstrated. That Said whilst the NAO hasnt been in full negative Phase it hasnt been a total washout of a Winter- Far from it- As we can see the NAO signal has been rather muted- probably because of the significant phase of the Pacific jet- However what we do see is although the Negative trend is not exactly amplified nor is the positive phases- Infact looking at the attachment below- We can see that there has been only one real positive phase at the start of Jan which didnt last longer than 2 weeks- Also we can see very cold air over the UK when the NAO is Neutral- This is perfectly illustrated by the 28 Dec 2005- We have a Neutral NAO with this Synoptic Pattern- http://www.wetterzentrale.de/archive/ra/20...00120051228.gif One of the highlights for me this winter has been the lower than Normal heights over the Iberian regions- This has gone some way to compensate the below Normal heights over greenland- What it also does is teleconnect to having a ridge supporting between the 2 anomalies- and this has allowed on 3 occasions a tongue or loop of Cold air to run back through scandi & filter in the back door of the UK- Sadly ALL these occasions have been at a point whereby that process had advected warmer air into central Europe ahead of the blocking- So we have a process of Cold replacing Milder blocking- There has however been a couple of occasions whereby we *ALMOST* got into the situation of Very cold air flowing from Very cold blocking- This came from when the polar vortex became displaced on the Southern side of the Russian high in January- this again stems from a Largly Negative AO set up- it is my Suggestion that again this pattern will cont Remember this going forward- NEUTRAL NAO still can equate to cold UK temps- The reason I highlight this is with the Pacific drivers the PDO & QBO being in phases that could lock in over the coming Winters we will have have to look forwards to more neutral dominated periods of the NAO despite the SST signature possibly become the key tripole Predisposing the NAO towards negative- With this in mind assuming that next year we arrive at a similar teleconnection juncture- Ie the PDO & QBO exhibiting the Strong Pacific Jet trend then most certainly we can look forwards to more of the SAME trend- This will tend to be in the START of the winter for Zonal or Semi Zonal flows punctuated by flat shaped mid lattitude blocking highs with Strong Negative height anomalies either Side - The Mean pressure anomalies for Dec & Jan from Philip Edens Site show exactly what I mean- http://www.climate-uk.com/monpre/0512.htm Dec 2005 http://www.climate-uk.com/monpre/0601.htm Jan 2005 Then as we reach the latter stages of the Winter this is where the Negative NAO signature can possibly take over (overwhelming weakening phases of the PDO & QBO )- allowing Larger Circular shaped highs developing indicating a meridional or Highly Meridional flows to develop Look at Feb 2006 http://www.climate-uk.com/monpre/0602.htm We can see the Nice High lattitude blocking from perfect Spawning conditions of Weakened Pacific Jet & Warm Stratospheric gas- between 60 & 75N Over the next few years this could also POSSIBLY encompass the first Parts of March- ( which is rare these days-) http://www.climate-uk.com/monpre/0503.htm March 2005 started the trend- but the pattern collapsed early on- Using Philip Edens data brings me onto a topic discussed by many posters throughout the winter from forum to forum- The inference that the mean location of the polar front in Winter has migrated further north - Philip has furnished me with some data that goes a way to prove that yes this is the case- Illustrated below As we can see both the Mean Low pressure & High pressure locations have made gradual progression Northwards- with further pressure INCREASES in the Iberian regions over the last 10 years- As well as lower centre pressure observed is lower towards iceland- This in my opinion does correlate VERY well with the increased frequency of Bartlett highs observed as well as that 'omni-Present' Icelandic Low- Now take this febs Actual- http://www.climate-uk.com/monpre/0602.htm Notice how the Icelandic Low has eased off a long way further west- Also the Azores High & Bartlett pressure belt is weaker and slightly further South- Notice the UK is almost in the 'Col'- with Pressure significantly higher than the norm to the NE- It looks more like a chart from the 61-70 mean.... Another pointer going back to prove that this Winter is 'Impressive'.......... I suppose that does cover most things this Winter- remembering that this is in my opionion still a Transitional year- inferring that the following years 'should' trend further towards what we are seeing now-( the highest expectancy of a moderate to severe winter comes on 07/08) This would be a Strong fast Flat pattern to start, Amplified Slow pattern to finish- the key is at the start- I stress that should the Stratopheric gas warming continue at those Northern Lattitudes it will only be a matter of time we get a 'Proper' old fashioned Easterly Phase- These tools and many others will come 'out of the box' for the next Winter forecast- But for now is Asta la vista to the 'QBO et al'- Suffice to say though that anyone harbouring thoughts of breaking out that new George foreman Barbeque set may have to keep them on ice for a while yet- The feedback patterns at the moment, depth of the azores high & the warmth of the Stratospheric gas at 75N do not support an early season plume up from the South- As the models begin to see the gradients rapidly changing & increasing from the South in the medium term they will jump on any chance to drive that polar front back north introducing Warm air - Sadly as the ensembles have shown over the last week- Overwelming support for big Mild 850 runs doesnt actually arrive- and we are now looking at possibly a Snowy episode for Saturday 11th March- The ensembles at the moment reflect the prospect of the first warmth arriving after that- Dont count on it TO much just yet- It MAY happen although as the varifiaction stats are in the low 80'%s at day 5-(T120) & the feedbacks are POSITIVE towards more northerly blocking march may still herald some surprises yet..... Regards Steve Thanks again goes to Philip Eden for the Pressure data...

Hi Daisy/All- Ive got a spare while at work- so I will put a few things down- its off the bat, and I appologise for any errors/typo's etc- I suppose before we go into teleconnection an educated understanding of what it all means- for example Im not a baker- but I know what a good loaf of bread tastes like- So with that in mind Teleconnections are measures & variations of the Sea surface temperatures and atmospheric Pressure- The reason the teleconnections are called oscillations are because at regular intervals they the components of their make up are predisposed to a certain state- The teleconnections are as follows- SST' driven are- ENSO- El nino Southern oscillation- ( the actual measure though in terms of reference & forecast is the SOI) PDO- Pacific Decadal oscillation Atmospheric Pressure Driven AO- Artic oscillation NAO- North Atlantic Oscillation QBO- Quasi-Biennial Oscillation MJO- Madden-Julian oscillation PNA-Pacific/North American ( for reference to the QBO read GP's pacific pointers thread) It would probably take hours & hours to describe them ALL- however its all very similar to a tug of war- Lets assume we have on one side a Cold UK winter & on the other a MILD UK winter- THE winner of the tug of war will be the combination of the teleconnections which predisposes the atmosphere towards- either warm or cold- * NB: what is cold for the UK MAY not mean cold for the other areas of the GLOBE- You would think that way forwards is to put into rank order the teleconnections that MOST apply to OUR neck of the woods- However its not that straight forward- ALL of them are interlinked and often Mute another- The 'classic' Teleconnection is the El nino - IF this is positive in a big way ( Or negative La nina) it has massive effects on global circulation patterns- This isnt really the thread for going in depth on this one- BUT it is NEUTRAL this season & has NO further effects- Many people fall into the trap of viewing the UK under the microscope- interms of looking at patterns over the atlantic BUT thats TO narrow a viewpoint- EVERYTHING starts in the pacific & works its way EAST- firstly manifesting in America & then down the line to the UK- So this i why we look upstream to see developments- I suppose the way to gradually increase knowledge here is to NOT try to understand each & every one, but develop knowledge on ONE subject that be the Jet stream- The reason I say this is All the above oscillations are are measures measures of anomlies- If you havent got a sound base of knowledge on these to make the jump from these measures to forecast then the best thing to do is work your way back from a common denominator- That be the jet stream- At the end of the day when all said & done the END result of the teleconnections working in harmony provides us with the likely position of the jet stream- I hope there is a little knowledge here from the readers point of view- but once we can get a definative steer on jet stream location ALL forecasting becomes a hell of a lot easier- With a base knowledge of this, but studying the continued locations of the jet stream & strength you can work backwards and make assumptions about the phase of the teleconnections- So I would when studying the charts ( and anyone for that matter) make a POINT of looking at the 200's & 300 Mb charts for the jet stream- Click this link And goto Northern Hemisphere then 200Mb charts Understanding this is Key-........ Below is a few teleconnection pointers- AO- the mean pressure differential between the pole & the Equator- When Strongly negative it indicates that there is High lattitude blocking & low pressures taking a southerly track around the globe- This is GOOD news for the UK getting cold as we do need high lattitude blocking to our North to send the cold air south Even though the AO MAYBE sharply negative the UK can still be on the mild side- as the Negativity of the AO may only apply at that point the Pacific I mentioned this earlier though ( and forgive me for going a little statistical again) there is a linear correlation between the AO & NAO being Negative - Linear correlation is basically a statement regarding how well 2 parties associate with one another- +1 being they match perfectly 7 Work in tandem, 0 meaning they have NO direct impact, and -1 would be they are opposite- A Classic -1 Linear correlation would be an icelandic Low & a Negative NAO- it doesnt happen- However the correlation between negative AO & negative NAO is ~ 0.6+- which means once the AO is neg it is often ( but NOT always long before the NAO follows) The NAO- probably the most talked about teleconnection on the forums- Remember all the measure is is the pressure differential between ~ the Azores & iceland Its almost IMPOSSIBLE to get very cold with a positive NAO- but there are manifestations of both neutral & negative that can provide the UK with the Bitter Stuff- The 'Classic' NAO in everyones imagination is the Greenland High and low pressure to our South East giving that Cold feed- However cast your mind back to the Armagedden charts of last nights 18z and that was a Neutral NAO because there was A high pressure just to the NW of the UK but LP over Iceland & low pressure to the SE- so the differential was LOW- I think the term Negative is after a measurement of -1 NAO if you are every checking the links- With reference to the above 2 teleconnection- there are LOTS of manifestations of the 'blocking' which is the pre-requsite for Cold for the UK- and so occasionally these 2 arent great at demonstrating cold if they show as Neutral- The PNA is another differential measure of Pressure between the coasts of America- What forecasters do when observing this is look for phases of the PNA- either +ve or –VE to demonstrate the Strength of the jet stream- If the PNA is big +VE then that indicates there is a large amount of blocking, and this should then replicate downdstream- However there is a NOT im afraid a direct correlation with +VE or –VE PNA to UK Cold- its just something that is a HELPFUL GUIDE- Similar to the NAO the PNA has MANY MANY manifestations and unless again you have had experience of them all it would be hard to place a forecast just based on little experience- The PDO- Measures the Sea surface temperature anomalies in the North west Pacific- Some people would find it strange that this region is measured & in particular how it effects the UK But… again the Negativity or Positivity has a marked effect on the Jet stream into the Pacific North west of America- The more NEGATIVE it is the Stronger the Pacific Jet is- So there- ive summarised them for the best part- they all have a meaning- however with limited knowledge my suggestion is an overview for knowledge purpsoes rather than indepth knowledge- The way forwards to ANY beginner/Novice perhaps intermediate is to spend time looking over the Jet stream patterns- that CANNOT be emphasized enough- The location Jet stream is as I said at the start the Net result if all the PUSHING/PULLING, STRENGTHENING/WEAKENING that the teleconnections exert on it- When looking at the runs of the models spend as long as possible on the 200’s & 300’s, they tell the story before its even happened- Key 2 Phrases on Jet stream are- Zonal & Meridional- Zonal refers to a jet that is WEST to EAST & STRONG - NOT good for cold weather fans- Meridional refers to the jet that is NORTH to SOUTH & Weak- good indicators to cold for the uk….. Best regards Steve