Autumn And Winter Lrfs

[The Enforcer]

Another thing that struck me was how quickly the media latched on to any impending cold spell, some of the tabloid headlines, especially in the Daily Mail/Express/Star were laughable, it was almost as though they were getting their info from the maddest snow/cold rampers on this board and reporting them as fact incorectly attributing them to 'met office sources'.

I have a particular dislike for media spin making more out of something than the facts state. It is true that the reaction of the media is not dissimilar to some of the hype and hysteria that can emerge on the forum and in some cases I notice that the two arms of exaggeration serve to feed each other. For me it's blatantly obvious that an upcoming cold spell does not necessarily equal sub-zero daytime maxima and snow drifts - once bitten, twice shy. Others take the bait every time.

[johnholmes]

MSLP - that's a new one on me. What's that when it's at home?

I do always ask people to explain abbreviations, some do some don't! We all have differing levels of understanding.

MSLP=Mean Sea Level Pressure, the lines you see on the BBC charts that Met Office forecasters sometimes show when explaining what may be happening in the Atlantic.

hope that helps

John

[The Enforcer]

MSLP=Mean Sea Level Pressure, the lines you see on the BBC charts that Met Office forecasters sometimes show when explaining what may be happening in the Atlantic.

The ones measured in millibars? I know them. Cheers old chap. Actually, i'll re-phrase that as 'not so old chap', so as not to risk infringing the new rule.

Edited July 17, 2006 by The Enforcer

[SMU]

The ones measured in millibars? I know them. Cheers old chap. Actually, i'll re-phrase that as 'not so old chap', so as not to risk infringing the new rule.

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

Edited July 17, 2006 by Steve Murr

[The Enforcer]

Philip Eden creates an MSLP anomaly map for the month which we can use to varify-

http://www.climate-uk.com/monpre/0606.htm

Seen those before, very useful. Especially if the archives go back some years.

[SMU]

Seen those before, very useful. Especially if the archives go back some years.

Philip also does seasonal-

http://www.climate-uk.com/monpre/06QQ.htm

Interesting winter just passed- very out of kilter with recent form........

S

[West is Best]

NB: Lower than usual observed pressure over the azores- Sadly some people really do deliberatly overlook these when they really are Gospel-

S

Let's be crystal clear about this.

1. We're talking about a handful of millibars at best.

2. That's for June alone

3. The key this year is the extent and position of the Azores high, not its height. You can have a very high AZH, but if sits over the Azores it's about as much use to us in Britain as a sledge in winter, thus

4. what has happened this year is a much larger Azores high and, much more importantly,

5. it has ridged far up towards Britain.

That is why this summer is so classic. It's the building block for a fine settle British summer as most professional metereologists will point out. The fact that this summer has also been so dry is no accident. It's a concomitant of this type of synoptic set up.

Edited July 17, 2006 by West is Best

[Damien]

Expert?? Me?? You want to pick yourself a decent expert, if you want an expert and not one who sits in my chair. I would never, EVER claim to be an expert, in either field of meteorology, or climatology. I have no research qualifications and no professional experience. I am an amateur with a bit of knowledge. No more.

Sorry - you certainly know your stuff when it comes to the weather.

Well whether the NAO was positive or negative, the result was the same - cool, dry and nondescript. I doubt there is much difference between weak negative or weak positive anyway.

Theoretically.

But that's a very interesting theory anyway and may well be true.

Letdowns were only created by several poor short-range forecasts, which is another debate entirely.

I disagree in general. The short-range models were certainly not to blame for winter 2001/02. LRFs were.

But certainly for such snowless fiascos as late January 2004 this holds validity.

You cite 1990/1991, but how many recent weakly positive NAO winters have not produced widespread snowfalls? Have we even had any recent weakly positive NAO winters (using the Met Office measurement)? How does the overall long-term percentage mild:cold winters stack up when NAO is weakly positive?

2000/01 was, however so was 1988/89. 2003/04 however was another one and that brought *some* but still very pitiful snowfalls and yet another mild winter.

Further back I think 1975/76 was and that also did little. 1955/56 was another, and that brought a very 2000/01-like winter if you check the record books:

http://www.personal.dundee.ac.uk/~taharley/1956_weather.htm

. But remember - the recent trends (in this case winters) always count more in my books.

The fact that there was an eventual perception that they were correct saved them (I would dispute the correctness of that forecast to my dying day

As will I.

Their use of the NAO as a winter forecast could have been a public relations nightmare and it almost was, but they only get this bad press because of their prominence and the nations' metorological ignorance, which creates an expectation that the Met Office should always be correct!

That's true - but I think many people who *were* in the know through such contemporary and revolutionising sources as the weather forums, or just in the know anyway, expected the Met Office to be right - on the grounds that they have simply never been wrong before in the "Online age". And how wrong they were for most of the UK in 2005/06.

Hammerb32 - I certainly agree on the accuracy of the MetO and (to some extent) the BBC in the short-range. (Does Everton Fox still do these forecasts?) They were crucified in 2001/02 but in the end if only we should have listened to Bill & co..

Edited July 17, 2006 by Damien

[SMU]

Let's be crystal clear about this.

1. We're talking about a handful of millibars at best.

2. That's for June alone

3. The key this year is the extent and position of the Azores high, not its height. You can have a very high AZH, but if sits over the Azores it's about as much use to us in Britain as a sledge in winter, thus

4. what has happened this year is a much larger Azores high and, much more importantly,

5. it has ridged far up towards Britain.

That is why this summer is so classic. It's the building block for a fine settle British summer as most professional metereologists will point out. The fact that this summer has also been so dry is no accident. It's a concomitant of this type of synoptic set up.

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

Edited July 17, 2006 by Steve Murr

[paul tall]

Heh, just wait until snow is on our doorstep, or not

This is just a mere tiff.

[West is Best]

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-

You mean objective I think you'll find.

I have provided repeated facts Steve, you just don't appear to like them.

Don't forget of course that your height is skewed by the second half of June. And you haven't a clue what the pressure maps will show for July - I think they will show a +ve anomaly but it might be worthwhile waiting to see.

What's important here is the position and extent of the AZH. The height is not entirely relevant frankly. As I mentioned, you can have a very high AZH but it can sit right over the Azores which is next to useless for the UK. You can have a slightly weaker pressure because you have a much bigger Azores.

Think of it like a balloon that you blow up - a smaller balloon has thicker 'skin' but is smaller. The more you blow up the balloon the thinner the surface may appear, but the bigger the area it covers. This summer has been dominated by the Azores high ridging north and north-east towards the UK and spawning in the process high pressure cells right over the UK. I appreciate it's what I forecast, and not what you did, but it's 'unfortunate' that you persist with this as I don't think it reflects favourably.

[SMU]

You mean objective I think you'll find.

I have provided repeated facts Steve, you just don't appear to like them.

Don't forget of course that your height is skewed by the second half of June. And you haven't a clue what the pressure maps will show for July - I think they will show a +ve anomaly but it might be worthwhile waiting to see.

What's important here is the position and extent of the AZH. The height is not entirely relevant frankly. As I mentioned, you can have a very high AZH but it can sit right over the Azores which is next to useless for the UK. You can have a slightly weaker pressure because you have a much bigger Azores.

Think of it like a balloon that you blow up - a smaller balloon has thicker 'skin' but is smaller. The more you blow up the balloon the thinner the surface may appear, but the bigger the area it covers. This summer has been dominated by the Azores high ridging north and north-east towards the UK and spawning in the process high pressure cells right over the UK. I appreciate it's what I forecast, and not what you did, but it's 'unfortunate' that you persist with this as I don't think it reflects favourably.

Share with us these facts- - Thats facts not WIB fiction

you cant use the skew as an arguement - otherwise you become a hypocrite when discussing CET as you always claim that the CET is a perfect reflection- and that has skewwed moments in it- as for July it will be more pronounced for Europe than June

You didnt issue a summer forecast- Your patter was the same every week from May... the azores high is building its building- even posting up charts from t 300 of model runs to prove a point- Some forecast-

As for your balloon theory sadly whilst it sounds nice its typically flawed by the fact that the Earth & its pressure zones doesnt revolve around the Azores- Your assumption that the azores is the starting point for Every high pressure cell to develop is again wrong-

The basic principal of measuring observed pressure is to first take the standard SLP for that area- if the observed average is lower over a given time- in this instance a month then that area has had a WEAKER influence over the surrounding areas than what it has on the corresponding normal Average-

You then look to the area with the biggest anomaly & this is the area with MORE of a say in the surrounding area-

If you go back to the SLP maps-

http://www.climate-uk.com/monpre/0606.htm

You will see that the azores belt has a higher pressure than that of Central Europe which means yes it does control some of our weather, however because the observed pressure is lower than usual its influences are less-

I think anyone reading this thread with an ounce of common sense knows it- but most people have given up posting their thoughts & disagreeing with you because they are fed up with it- much as I am-

Im so fed with this arguement that I will call it a day & leave people to decide-

You can have opinions on forthcoming weather- Fine- but distorting facts as you do repetativly here wasts everyones time- especially newer people who may think that what you write has any element of Truth- which sadly it doesnt-

FACT- AZORES weaker than usual-

To back this up-

Lower than usual pressure observed over Azores- ( PHILIP EDEN)

Dryer air ( LOW RH) observed since june- to the point that people have commented on several times- this DOESNT happen with the azores high- you get high RH levels & humid air-

Philip edens quote for June-

Mean monthly sea-level pressure was above normal over most of Europe including the British Isles. The first half of the month was very anticyclonic, and although the second half was rather more changeable there was no extended spell of cyclonic or westerly weather. In the last 30 years only the Junes of 1995 and 1988 were more anticyclonic.

Doesnt mention Azores does he......

No Westerly Weather- Brought about by a common flat azores ridge-

Azores displaced North & west- Source PRO MET http://www.easternuswx.com/bb/index.php?showtopic=101157

I could go On............. But I wont-

Lets see your FACTS west - NOT your opinions-

finally quote.... You can have a slightly weaker pressure because you have a much bigger Azores

Er no.....

Its not a quilt cover-

Higher pressure= Larger DAM levels = Larger area exerted by said high pressure-

Thats why also we havent seen those dark red colours on the 500 MB charts so far over the azores region....

S

Edited July 18, 2006 by Steve Murr

[West is Best]

Steve you are really not arguing very effectively here - repeating the same point without proving anything. If you can show me a site which has archive charts already for 2006 I will demonstrate to you why I think you are talking complete tosh. But as I suspect you know full well all charts on net-weather in the recent past are output i.e. model charts and are, therefore, at the very best at least 6 hours ahead: ranging from 6 hours to anything up to 384 hours. The moment I have the 2006 summer archive charts I'll demonstrate what I have already demonstrated throughout this summer: namely that the Azores high has been extensive and ridging up to Britain. This has been the repeat pattern of the summer and each time it has been coming up I've tried to demonstrate it from the output models - along with other peeps of course.

I made my summer forecast in the model output discussion thread not the summer forecast thread. I didn't bother with convuluted upstream teleconnections because I didn't see much point. 2006 summer looked to me to be basically above average and dry, though I also gave a more specific June forecast in the June CET thread posted on May 29th: "I think it will be a mostly gorgeous month - and will feel lovely in the sun especially the first and last weeks, but some cold nightime minima early on and a brief unsettled spell in mid-month may peg the overall temp back a bit." I'm happy with that. My main summer forecast was, as I say, to the point: dominated by high pressure with repeated ridges out of the Azores high settling over the UK and hot and dry. TEITS saw my summer forecast and was kind enough to make polite remarks about how accurate it was. I hope you're not just having pique about this ...!

As I said - the key is the position and size of the Azores high. It always is in summer. If it stays over the Azores it can be as high as it likes, but it won't help the UK. If the jet starts kicking north it gives the Azores high a chance to ridge towards the UK and build. In common metereological parlance the word used is 'extend'. Now that word 'extend' is about size, not height. This is exactly what has happened this year. Sir Michael Fish explains is all perfectly here, and in layman's terms so that it's easy for those who find it difficult to follow: http://news.bbc.co.uk/1/hi/uk/3897867.stm

Summer 2006 has been dominated by an extending Azores high. This is not to say, as Snowprincess quite rightly points out, that it it is the only influence. The continent has of course also played its part, as has the mid-Atlantic on occasion. And I daresay somewhere in there your teleconnections have done something useful. But each time we look as if we're about to have a breakdown it's the Azores high ridging - extending - that has come to the rescue. The end of this week (this week, not the far flung future) that comes to the rescue. This week is a classic, classic, example of what has happened this summer. First, the Azores high builds and ridges:

Then it extends over the UK:

Finally the high pressure cell splits off to sit close by, introducing a very hot feed from the continent:

I make this the 4th time since May that I have posted up an almost identical synoptic development and that's highly significant. So I repeat: it's about the extent [/] of the Azores high this year: in other words, not its height but it's position and size. It has ridged north and east bringing the building blocks for this glorious summer.

QED

Edited July 18, 2006 by West is Best

[Glacier Point]

May MSLP anomaly:

May 500 hPa anomaly:

May surface temp. anomaly:

June MSLP anomaly:

June 500 hPa anomaly:

June surface temp anomaly:

No where on these charts do we see evidence of a strong or even displaced Azores High pressure area towards the UK - if anything the western Atlantic is where the high pressure, higher temperatures are manifested.

The 850 hPa temp charts provide the key to what is going on here:

http://www.wetterzentrale.de/pics/Rtavn001.html

The 200 hPa GFS jet forecasts also give a better insight into the overall flow pattrens:

http://wxmaps.org/pix/hemi.jet.html

There has been a notable weakness in mid and upper levels throughout the period in the eastern Atlantic related to anomalously low SSTAs throughout April and May. If the Azores was having such an influence on our weather, such a trough would not exist.

What we have been witnessing are the downstream responses to this trough with a ridge over western Europe. If anything, I would suggest the Azores to have had a lesser direct impact than normally expected. Without the ridge over NW Europe, we are prone to the kind of setup exemplified by 00Z GFS (by the way this is not an endorsement of this run) with Atlantic lows able to penetrate the UK.

Edited July 18, 2006 by Glacier Point

[West is Best]

I completely respect your view, even though I disagree with it.

Yours etc

West is Best

Edited July 18, 2006 by Osbourne One-Nil

[Osbourne One-Nil]

I'm wondering if anyone who isn't confident in their level of knowledge would be encouraged to post in this thread, or to share their views, or whether they'd be put off by the testoserone-fueled ego bashing that seems to be going on.

I've got nothing at all against differences of opinion, but why does it always have to turn personal?

Just stop it.

[johnholmes]

can you all read the heading of this thread please and post accordingly. Summer has its own auguing den.

Mods pse note the last posts should be deleted or moved to the correct thread.

John

equally as OON has just posted grow up, agree to disagree but stop spoiling posts with petty arguing about who is right. Again I repeat read the heading and post accordingly.

John

Edited July 18, 2006 by johnholmes

[Osbourne One-Nil]

Please just stick to the topic!!!

[West is Best]

Please just stick to the topic!!!

OK.

LRF's - difficult to do. Many mistakes can be made. Lots of debate needed. Just need to be nice. None of us immune from learning. Humility good quality in forecasting.

Basically, if forecasting was easy there wouldn't be the arguments ... We can't even agree about what's just happened, so we're never going to agree on the future.

[TEITS]

OK.

LRF's - difficult to do. Many mistakes can be made. Lots of debate needed. Just need to be nice. None of us immune from learning. Humility good quality in forecasting.

Basically, if forecasting was easy there wouldn't be the arguments ... We can't even agree about what's just happened, so we're never going to agree on the future.

LRF's are certainly difficult to do and I for one won't be doing a winter LRF this Autumn.

I feel I embarassed myself last winter with my LRF because all I really did was post what I hoped we happen which is why it failed miserably.

I would be better off reading and trying to learn and understand other people's LRF and the data they used to compile such a forecast. Hopefully one day I could produce my own LRF which would be based on science rather than hoping for E,lys

[SMU]

May MSLP anomaly:

May 500 hPa anomaly:

May surface temp. anomaly:

June MSLP anomaly:

June 500 hPa anomaly:

June surface temp anomaly:

No where on these charts do we see evidence of a strong or even displaced Azores High pressure area towards the UK - if anything the western Atlantic is where the high pressure, higher temperatures are manifested.

The 850 hPa temp charts provide the key to what is going on here:

http://www.wetterzentrale.de/pics/Rtavn001.html

The 200 hPa GFS jet forecasts also give a better insight into the overall flow pattrens:

http://wxmaps.org/pix/hemi.jet.html

There has been a notable weakness in mid and upper levels throughout the period in the eastern Atlantic related to anomalously low SSTAs throughout April and May. If the Azores was having such an influence on our weather, such a trough would not exist.

What we have been witnessing are the downstream responses to this trough with a ridge over western Europe. If anything, I would suggest the Azores to have had a lesser direct impact than normally expected. Without the ridge over NW Europe, we are prone to the kind of setup exemplified by 00Z GFS (by the way this is not an endorsement of this run) with Atlantic lows able to penetrate the UK.

Great factual post GP Notice the 500 HPA SLP anomaly to the NW atlantic is the exact same anomaly on the eastern us thread I linked to- Displaced azores high anyone!!!!!

Cheers for wasting... Sorry spending that time to prepare it-

John agreed this discussion is in the wrong thread - point taken-

OON- Its not personnal its a direct discussion revolving around a specific point - Its nowt to do with Ego - I actually think that we under estimate peoples knowledge here- I think most people understand-

Sure its gets scientific but we are studying the weather- which is a science-

West I will have a read of your post later- cant do much here at work-

S

Edited July 18, 2006 by Steve Murr

[West is Best]

West I will have a read of your post later- cant do much here at work-

S

Don't worry about it Steve. I think it's time you and I moved on with this or we'll incur wrath ... in due course when I see the 2006 archives I'll do a demonstration. I don't think anywhere publishes the charts that have just occured do they? NW archive charts only go up to 2005, so I have no option but to use model output charts.

Anyway, time to move on

[BLAST FROM THE PAST]

Folks

Can someone explain the METO stance this winter. I take it the METO are basing this forecast on the SST in May? Were they not very similar to last year if not more inviting? I see that big Stevie MURR has mentioned the warm SSTs off Newfoundland as a possible reason as it suggests a positive NAO.

regards

BFTP

[Glacier Point]

Folks

Can someone explain the METO stance this winter. I take it the METO are basing this forecast on the SST in May? Were they not very similar to last year if not more inviting? I see that big Stevie MURR has mentioned the warm SSTs off Newfoundland as a possible reason as it suggests a positive NAO.

regards

BFTP

Herein lies the link with current discussion about the prolonged alignment of flow patterns in the Atlantic - they will have an impact on autumn and winter through the Sea Surface Temperature Anomalies (SSTAs).

I think this thread has picked up quote well the potential threat to any cold winter through continued warm southerly flow up the western Atlantic during the summer promoting warm SSTAs and as a result, the winter polar jet being pepped up off Newfoundland.

Another aspect is the upper level weakness in the eastern Atlantic and the mean NE'ly flow there likley to result in cold anomalies during the winter from residual SSTAs - potentially inducing a trough over western Europe and displaced jet flow to the south.

GP

[SMU]

Don't worry about it Steve. I think it's time you and I moved on with this or we'll incur wrath ... in due course when I see the 2006 archives I'll do a demonstration. I don't think anywhere publishes the charts that have just occured do they? NW archive charts only go up to 2005, so I have no option but to use model output charts.

Anyway, time to move on

Here is the direct link to the pubished ACCURATE FAX CHARTS-

http://www.wetterzentrale.com/topkarten/tkfaxbraar.htm

Not many people have it- but there is no arguing with an accurate reading of the fax..

S