Model Output Discussion 30/06/2012

[snowmackem]

I must say im surprised and dissapointed, however all is not lost yet! Meto 16-30 day update is plenty of fine and dry weather still to come and although the ECM has now come in line, we have rising angular momentum again and GWO pushing into phase 3, MJO into phase 4 - this all equates to better than what is showing. I think more twists and turns can be expected yet!

What I don't understand, is, all the teleconnections are telling us that the weather shouldn't be being forecast as it is, there appears to be a real conflict taking place. All the signs, angular momentum,gwo,mjo, GP'S, Chio's and others thoughts seem to be telling us that the pattern is changing (and therefore the symptoms i.e. the weather) to a generally more summery outlook, yet more and more model runs appear to be converging on the fact that by the end of next week we may as well put on the winter clothes again??

I really don't see the fun in 13 deg and persistant rain at the end of July !

Can anybody explain the differences of opinion between current model output and the current teleconnection signals, it would be much appreciated,

Thanks,

Karl

[Downburst]

What I don't understand, is, all the teleconnections are telling us that the weather shouldn't be being forecast as it is, there appears to be a real conflict taking place. All the signs, angular momentum,gwo,mjo, GP'S, Chio's and others thoughts seem to be telling us that the pattern is changing (and therefore the symptoms i.e. the weather) to a generally more summery outlook, yet more and more model runs appear to be converging on the fact that by the end of next week we may as well put on the winter clothes again??

I really don't see the fun in 13 deg and persistant rain at the end of July !

Can anybody explain the differences of opinion between current model output and the current teleconnection signals, it would be much appreciated,

Thanks,

Karl

I'll explain. over 5 years of reading on this thread I have noticed that when a change is forecast certain teleconnections are trotted out to show, "yes well as I had predicted this would etc.. etc." if it verifies we get a I told you so etc. John H for one does not do that, he is very truthful and restrained in his forecasts and sticks to the facts, the H500 output the pro's use. Others, well I have to laught and one particualr expert who comes out and then vanishes. As I have said before if only you could capture the hot air spouted on here from some experts one would be certain of a heatwave.

I do feel anxious about the opening of the olympics, but the fact is whoever wins the contests will deserve it good or bad weather. It's one planet and you should be proud of it!

[SP1986]

Perhaps we need to go back to the drawing board re: our understanding of teleconnections, or perhaps realise they are as likely to change as the model outputs themselves?

Anyhow it seems chasing hopes of understanding how the models work are continually dashed?

Anyway you look at it, the trend does appear to be backing away from sustained high pressure influence, to one where low pressure has more influence towards the end of the allotted run times.

[WhiteFox]

Personally I think of forecasting with teleconnections as very interesting yet still in its infancy. Some posters have become quite skilled in providing analysis, but they should be treated in the same way that john treats the upper air forecasts; they can give a good general indication of probable conditions but they cannot accurately forecast surface synoptics. Although the teleconnections may indicate an increased probability of a particular outcome, they do not mean that a particular outcome is a certainty.

Also, I find posts commenting on longer range forecasts for oscillations such as the AO and NAO to be somewhat misguided as they are merely a measure of the difference in pressure between two areas and, as such, are subject to the same errors as synoptic forecasts.

Anyway, the way I look at it is that teleconnections can indicate a forthcoming pattern change. When the 500 charts start to show a change then I start to take notice. John has heralded the upcoming change for about a week I think, so sometimes the tried and tested methods prove the most accurate....

[Gael_Force]

There are two new unknown quantities in the mix at the current time - record low amounts of ice in the Arctic and a sun that is behaving in a way not observed for at least a hundred years. It is a bit premature to rubbish or dismiss those who are relying on teleconnections as we know/knew them; These may still be operational but being overridden by processes that are yet to be properly understood.

[Downburst]

There are two new unknown quantities in the mix at the current time - record low amounts of ice in the Arctic and a sun that is behaving in a way not observed for at least a hundred years. It is a bit premature to rubbish or dismiss those who are relying on teleconnections as we know/knew them; These may still be operational but being overridden by processes that are yet to be properly understood.

There might be some truth in this, however the near term model output is as much as one can trust and it is based to a very large degree on the scientific facts inputted as open variables into an algorithm. The tele signals are and have always been week inputs that some folks are tyring to give the impression are able to produce definitive outcomes re the atmosphere looks like this when we have this MJO or ENSO etc, total nonsense, never mentioned by forecastors in public. When you heatrthe ITV weather say in 10 days time we will have sustained cold or warmth etc you will know it is a worthwhile endeavor. Until august bodies liek that spout it ignore it.

[chionomaniac]

I'll explain. over 5 years of reading on this thread I have noticed that when a change is forecast certain teleconnections are trotted out to show, "yes well as I had predicted this would etc.. etc." if it verifies we get a I told you so etc. John H for one does not do that, he is very truthful and restrained in his forecasts and sticks to the facts, the H500 output the pro's use. Others, well I have to laught and one particualr expert who comes out and then vanishes. As I have said before if only you could capture the hot air spouted on here from some experts one would be certain of a heatwave.

I do feel anxious about the opening of the olympics, but the fact is whoever wins the contests will deserve it good or bad weather. It's one planet and you should be proud of it!

There might be some truth in this, however the near term model output is as much as one can trust and it is based to a very large degree on the scientific facts inputted as open variables into an algorithm. The tele signals are and have always been week inputs that some folks are tyring to give the impression are able to produce definitive outcomes re the atmosphere looks like this when we have this MJO or ENSO etc, total nonsense, never mentioned by forecastors in public. When you heatrthe ITV weather say in 10 days time we will have sustained cold or warmth etc you will know it is a worthwhile endeavor. Until august bodies liek that spout it ignore it.

I don't think that I have seen anyone come on here and proclaim to be an expert, Downburst. However, to completely disregard an area of forecasting that is still in its infancy is disingenuous. With that type of attitude then we would still be believing that the earth is flat.

The met office readily admit in research and papers highlighted elsewhere on this forum, that tropical events such as ENSO, the MJO etc do affect us (extratropically) and that this is these are neither fully understood or factored into the models as well as they could be. Using teleconnective indices and events to help forecast weather events locally is fraught with danger and may not always lead to the correct solution. However, it is well understood taking the MJO for example, that each phase creates a particular long wave pattern that can referred to. We still need to be able to accurately predict the MJO though, and herein lies where difficulties in predictions may occur.

It is easy to be destructive about teleconnective forecasting methods - less easy to be constructive. As ever, I find that those who know least about teleconnections and how they may influence global weather patterns, are often the first to shout the loudest when ridiculing others who spend a lot of time and effort researching this.

[tinybill]

morning all i just hope on the opening of the Olympics they got there wet weather gear looks like they might need it!!

[full_frontal_occlusion]

Downburst:

There is of course nothing wrong with amateur meteorologists seeking to advance understanding and therefore improve medium-long term predictive ability. There is also nothing wrong in the competitive spirit of seeking to better the experts; this is after all a huge part of the fun and motivation for many people. It's a sort of sport.

So very often science is advanced through serendipity so why not have those emerging ideas and theories tested by people who have a real passion for weather prediction on such forums?

It is one area of science which can be delved into by lay-people using nothing more than patterns, logic and analogues without the need to understand the complex physics and mathematics beyond a relatively simple level.

People also come here to exchange knowledge, spar and generally indulge in their pass-time with other like minded individuals and in so doing, hopefully increase their knowledge and enrich their lives.

If people want access to the experts and discuss emerging science at the professional scientific level then they have to go through the hard earned process of advanced education and find a career in meteorology.

But that ain't what this site is about?

I for one, welcome the inputs of every contributor - far far too often science is damaged by those who would rather treat it as an elitist society and close off the very fruitful avenues for amateurs that make meteorology so much fun.

ffO.

Edited July 21, 2012 by full_frontal_occlusion

[mushymanrob]

I'll explain. over 5 years of reading on this thread I have noticed that when a change is forecast certain teleconnections are trotted out to show, "yes well as I had predicted this would etc.. etc." if it verifies we get a I told you so etc. John H for one does not do that, he is very truthful and restrained in his forecasts and sticks to the facts, the H500 output the pro's use. Others, well I have to laught and one particualr expert who comes out and then vanishes. As I have said before if only you could capture the hot air spouted on here from some experts one would be certain of a heatwave.

I do feel anxious about the opening of the olympics, but the fact is whoever wins the contests will deserve it good or bad weather. It's one planet and you should be proud of it!

i think thats abit unfair tbh. this is a public forum, open to anyone (who joins) to express their views on what the (extremely complicated) weather data is telling us.

not happy with this mornings runs which are starting to confirm what the gfs first picked up on... ie a return to low pressure domination later next week. as it stands there could be more torrential widespread thundery showers, in a muggy, humid, but warm airmass.

[Alex]

Not too bad if the ECM 00z verifies, the low is pushed east over time and the ridge pushes in again from the west. Could well be very warm and thundery on Friday.

On another note i'm going to the met office open day today, anyone else going?

[johnholmes]

well GFS continues with its wet Olympic opening ceremony. After I think now 5 consecutive runs from it with a similar idea it does have to be taken seriously whatever any other model shows. I suspect the end result will be something of a half way house between the models but the prospect of a dry clear evening is now the minority view.

Pity the poor senior man at Exeter today and over the next day or two as they try to decide just which model has the most likely 'picture' for next Friday.

Interesting model watching again for sure.

just to add the 500mb anomaly charts this morning, valid for 7-10 days time, continue with the 'spanner in the works' sort of idea from yesterday. At least the GFS one does, close cut off 500mb centre close by SE UK; ECMWF shows a north of west flow but is still having nothing to do with the GFS version. You have all seen me post regularly that if they do not agree with one another then less confidence can be put on the upper air pattern for that period. The NOAA version from last evening favoured the ECMWF version again.

Nope-not jealous of the Exeter senior man at all at the moment!

Edited July 21, 2012 by johnholmes

[ANYWEATHER]

i think thats abit unfair tbh. this is a public forum, open to anyone (who joins) to express their views on what the (extremely complicated) weather data is telling us.

not happy with this mornings runs which are starting to confirm what the gfs first picked up on... ie a return to low pressure domination later next week. as it stands there could be more torrential widespread thundery showers, in a muggy, humid, but warm airmass.

Yep.I have to agree with this,even though some prefer for more general reliabilty that of the Ecm, Gfs was really the first to pick this up and ecm has someway backed this up,and this Gfs output cannot be dismissed and tbh looks the eventual outcome in one form or another! Problems with flooding too again if this comes off!

[bluearmy]

we should remember that generally speaking, the less amplified picture of events a week hence is closer to the mark. given that all the modelling has a fairly amplified pattern, thats a tricky one. JH mentions the half way house scenario and if i had to guess, i suspect thats where we are going. however, even a cut off upper low cant be ruled out within a pretty warm upper airmass. no one can say for sure what will happen beyond thursday and the sypnotic variations on offer have some pretty huge differences re resulting surface conditions.

[shedhead]

we should remember that generally speaking, the less amplified picture of events a week hence is closer to the mark. given that all the modelling has a fairly amplified pattern, thats a tricky one. JH mentions the half way house scenario and if i had to guess, i suspect thats where we are going. however, even a cut off upper low cant be ruled out within a pretty warm upper airmass. no one can say for sure what will happen beyond thursday and the sypnotic variations on offer have some pretty huge differences re resulting surface conditions.

That is precisely what I've been saying for the last 2 days, GFS too extreme, so a half way house still looks the form horse. Whatever way you look at it tho the plan to get the main trough set up to our east as we go into August just looks plain wrong, with a pattern more akin (but not as bad) to the first 7 weeks of Summer looking rather more likely as things stand, regrettable as that clearly is for the vast majority of us.

Edited July 21, 2012 by shedhead

[legritter]

found latest 120 fax chart of interest .so next wed onwards very interesting with many outcomes .meant to post a couple of days ago for the benefit of new posters .remember its the weather and subject to change .keep reading as many posts as possible there is a wealth of knowledge on NET /W .i started looking in about 5 yrs ago ,posting now for18months .i have learnt a great deal from this site .back in the 80s i payed for fax charts from bristol w /centre 2 days to get to you ,but now a click on the mouse .when i was a paid up fellow of ROYAL met society i recieved a wealth of knowledge ,but no longer a fellow but very happy with net weather .we have a very interesting spell of weather coming up ,a real mix of air masses and a strong sun ,and the french possibly sending us some action ,enjoy ,as other more knowlegable posters will be posting plenty of information ,read it and if you dont understand ASK THE QUESTION ,just had a look at a few sites in europe ,have a look on euro forums ,they will be concentrating on their weather ,its a bit like a puzzle ,but with a few pieces missing ,then build up a picture BUT BE WARNED [its liable to alteration .cheers legritter

[bluearmy]

That is precisely what I've been saying for the last 2 days, GFS too extreme, so a half way house still looks the form horse. Whatever way you look at it tho the plan to get the main trough set up to our east as we go into August just looks plain wrong, with a pattern more akin (but not as bad) to the first 7 weeks of Summer looking rather more likely as things stand, regrettable as that clearly is for the vast majority of us.

not sure about that shed. i think that troughing to our east is where we are headed. its just that it may well swallow us and nw europe up aswell. naefs 00z not quite as poor as naefs 12z was yesterday but not far off. i dont feel particularly confident in its output at the moment. dont know why as its been very consistent about dropping in the low anomolys into early august. i just feel there is too much flip flopping going on to trust what the models (even the ens ) are showing beyond the back end of this week. if, the ens are close to verification, the only positive spin i can put on things is that the overall pattern looks to be rather more mobile than we have become used to so the poor periods will be interspersed with better ones. of course, you could forget about all of this and go out enjoy the sunshine !!

[shedhead]

not sure about that shed. i think that troughing to our east is where we are headed. its just that it may well swallow us and nw europe up aswell. naefs 00z not quite as poor as naefs 12z was yesterday but not far off. i dont feel particularly confident in its output at the moment. dont know why as its been very consistent about dropping in the low anomolys into early august. i just feel there is too much flip flopping going on to trust what the models (even the ens ) are showing beyond the back end of this week. if, the ens are close to verification, the only positive spin i can put on things is that the overall pattern looks to be rather more mobile than we have become used to so the poor periods will be interspersed with better ones. of course, you could forget about all of this and go out enjoy the sunshine !!

Well I of course meant troughing far enough east to put us on the warm side. I tend to think we will find the trough east of it's June/early July position, but still close enough to keep us in the crap, hence my 'not as bad' in brackets. As for going out and enjoying the sunshine, I fully intend to after work.... we might not see it again until Sept after next week

[Backtrack]

Just wondering what the chances are the models will shift this further north to give us in the north at least a fighting chance of some sunshine Tuesday - Thursday?

[Thundery wintry showers]

The main issue into early next week is a pesky front which originally looked like it was going to push SE giving a belt of cloud and progressively lighter rain, preceded and followed by predominantly dry sunny weather, but now, the front looks like hanging around for a while. The rain belt will progress into north and west Scotland on Sunday, and will reach a large part of northern England on Monday. After that, it's not certain where the front will end up. The latest GFS run has the front again over northern England on Tuesday, and then into the Midlands on Wednesday- not much rain left on the front by this time, but extensive cloud cover is likely. To the south-east of the front, it will be dry, sunny and warm, while to the north-west, probably also dry and sunny but with average temperatures by day and chilly nights.

The GFS is probably overdoing the low to the SE towards the weekend but there is now pretty strong agreement that the high pressure will be eroded by a thundery low coming up from the south and a cooler cloudier type regime coming down from the north. Things could well go "bang" towards the south with a warm humid airmass moving up from the south and temperatures possibly hanging around in the mid to high 20s, but for Scotland and northern England, yet more persistent rain may well be on the cards.

I don't expect any parts of the country to be quite as grey as in the late-August 2008 quiet spell, but parts of northern England may well come out of the upcoming anticyclonic interlude with a shortage of sunshine and near average rainfall. Most of Scotland and southern England will probably be both drier and sunnier than average between now and Wednesday.

[johnholmes]

not sure about that shed. i think that troughing to our east is where we are headed. its just that it may well swallow us and nw europe up aswell. naefs 00z not quite as poor as naefs 12z was yesterday but not far off. i dont feel particularly confident in its output at the moment. dont know why as its been very consistent about dropping in the low anomolys into early august. i just feel there is too much flip flopping going on to trust what the models (even the ens ) are showing beyond the back end of this week. if, the ens are close to verification, the only positive spin i can put on things is that the overall pattern looks to be rather more mobile than we have become used to so the poor periods will be interspersed with better ones. of course, you could forget about all of this and go out enjoy the sunshine !!

I would support the idea of not much confidence ba

these are my rough notes after a close look at the last 5 days of 500mb outputs from the 3.

Comments before see noaa=done 1044 sat

Ec has 3 main trough, gfs has 5, noaa this morning are uncertain after day 5(thur) which gives best idea for states, prior to that favour ec version.

Last eve noaa had 4? main troughs

At start of this check ec had 3 gfs 3-4 and noaa 3+ main troughs

Why has gfs created almost meridional flow over states and probably consequently downwind into uk/Europe area? Is it a logical setup in the pattern, if so why has not ec or noaa done the same?

I suspect the questions I pose to myself in the above is probably what is exercising my ex colleagues in Exeter this morning as well?

Why has gfs altered the flow so much, is it a rational follow on, again if it is why has not ecmwf and noaa followed it. Again noaa looking at their 'chat' this morning are equally uncertain about which model gives the best guidance for their area after day 5/6. The pattern upwind obviously has a knock on effect for this part of the world.

very intriguing with gfs sticking on its 06z ouput to its idea first shown 24-30 hours ago with none of the others yet following it in any way?

That said if one looks closely at the 8-14 day NOAA chart from last evening then there is a slackness in the 500 flow off NW Iberia and the (sorry GFS should read ECMWF) output this morning leans even more towards that idea. The eastern trough, at 55N shown at 15-18 east is at 10 west by the time its over Iberia.

It does seem at the moment as though the weight of model evidence is for some probably modified version of the gfs output by Friday?

Edited July 21, 2012 by johnholmes

[swebby]

Am i right in thinking that the 6Z GFS is heading more towards the ECM with a low diving SE round the top of the high rather than a low developing in situ over northern france?

Edit

Hmmm maybe not! I'm afraid i was getting my hopes up on that.

Edited July 21, 2012 by swebby

[mushymanrob]

my concern is that imho the gfs 's evolution looks very plausable, its a smooth, logical one, mind you that doesnt mean itll be proven correct!

[Bobby]

We're in quite a different pattern now to what we were into, with Greenland high gone and high pressure ridging over UK for the next few days.

NAEFS seems to show some support for that with GFS low with negative anomalies reappearing this time next week with an Atlantic high creeping towards Greenland way.

+174

Then later in the run high pressure has migrated to Greenland and the low anomalies grow

My wager is things will be becoming more unsettled again by the end of next week although more rain for the North early next week

[Summer Sun]

A typical August is showing on GFS this morning with lots of low pressure systems around bringing more un welcome rain to many parts