Model Output Discussion 13/11/13 >

[Yarmy]

Let's compare the big 3 at T144:

 

ECM

 

UKMO

 

GFS

 

So much uncertainty and it'll all be different again in 24 hours.

[Joe Levy]

Wise words. Over the years many on here get wrapped up in too much detail run to run. We must step back and take an overview here - back at the start of November many were calling for a pretty flat pattern through until December. I called the same myself though I saw it more of a NW than W pattern and wasnt sure where the meto call of an above average November was coming from. IB used the word "zonal" about 4 times in one night, calling it game over for the month.

 

Where are we now? Details aside the whole global circulation pattern is much more meridional than many expected, and we have blocking in both the atlantic and pacific sectors that is giving the vortex a hard time. Suddenly we are not seeing low pressure firing out of Canada and there is a sense of a stalling atlantic pattern in the air. Final juicy mouthful is the meto update which is clearly an upgrade in terms of snow potential.

 

Enjoy the ride, but dont get stuck on detail. And revel in the fact that many people, including myself, may well have misjudged the next 4 - 5 weeks. As ever time will tell. It's only Nov 15 and I dont think realistically we could have hoped for much better when you recall where we were 2 - 3 weeks ago. Just to remind you how it was only 12 days ago!

 

I completely agree with you. One of the key problems is that we instinctively look for absolutes. We want definitive answers to questions that do not have definitive answers! I remember how pleased I was that March was so cold, and when that enormous low looked like it was going to hit the South West, it was very exciting indeed! But a slight alteration of its course completely changed that and we got almost no snow from it in Exeter! So even if we do get cold synoptics, that does not mean we will be lucky with the specifics. Equally in reverse, not so cold synoptics can bring surprises. Last October, late in the month I believe, higher parts of Somerset got up to 3 inches of snow because of evaporative cooling and a cold surface flow on the back edge of a weather system.

[johnholmes]

I don't really see meteorologists discussing the MO, I have no problem with the terminology myself even if it is somewhat vague.

I would take it to mean the jet unless they had posted a pressure chart in which case I would assume they meant low pressure or a shortwave perhaps.

The reality is the vast majority of us are not professional meteorologists primed and loaded with a sacrosanct terminology.

 

you have just hit the nail on the head that myself and forecaster queried.

You have given more than one explanation-that has to be confusing for new folk trying to understand the model thread, or so I would think? It is not a 'club' that any professional on here belongs to I can assure you. Those used to my posts over the past 8-9 years know I always try to use basic terminology and if I use accronyms or technical terms I explain them.

[Catacol]

Latest on the models from Gibby

 

The net result looks like a period of UK high pressure giving fog and frost but with little high level blocking in evidence tonight from GFS and ECM it looks like a steady road towards the Atlantic train before too long.

 

 

 

I dont think I have ever taken issue with Gibby before - he and I are Somerset folk after all - but I think this conclusion is wrong. You can come at this from all sorts of teleconnective angles, but as this is the model thread I'll stick to models. There is too much data out there showing very little in the way of the atlantic train at all. GFS picked the rise in pressure in the mid atlantic that we are about to see a good 10 days ago. So... the GFS control run here is certainly not a train:

 

 

 

 

and this ECM Ensemble mean at 240 clearly shows higher pressure to our NW and lower pressure to the SE, an absence of low pressure to our west and the vortex sat over Siberia. None of this points to an atlantic train

 

 

 

So stay calm. Charts flip and flop and its only November.... and the outlook broadly is still pretty good.

Edited November 15, 2013 by Catacol_Highlander

[Catacol]

 But a slight alteration of its course completely changed that and we got almost no snow from it in Exeter! 

 

Yuck - dont remind me. We got literally nothing from it only 35 miles further north. I was spitting with fury!

[Joe Levy]

Yuck - dont remind me. We got literally nothing from it only 35 miles further north. I was spitting with fury!

It has taught me to never taking anything for granted weatherwise! I pride myself in not having an opinion on what will happen to the weather over the next few weeks, as from my assessment of the model output and different people's theories, I can see quite plainly that noone actually knows what will happen either, which tends to be normal with the weather lol! It is fun to speculate, but I am not prepared to tie my emotions to the pretty colours of a cold chart haha!

[johnholmes]

Detail will, always will be, in shorter range charts, say T+12-T+72, the broad scale will usually be fairly clear some 48-72 hours ahead of that. Note I said broadscale. If it is where will it snow detail then forget any chart beyond about T+24, 48 at the very most for a general idea. I have lost count of the number of times I say 'will it snow for me' requires about 8 variables compared to 1 main one for will it rain in the summer. Think how difficult that is to get correct before wondering why snow forecasts are quite often not correct even 24 hours out. How long the cold, whatever definition you want to use for that, lasts looks, using the 500mb anomaly charts and data from further out, suggests to the end of November, possibly longer. Certainly I would be surprised if anywhere recorded mild 24 hour temperatures in that time scale. Mild, I think, about 3C above whatever is the average for your particular area from about Monday onwards.

[chionomaniac]

All the big 3 show reasonably similar synoptics now at 144hrs.  

 

 

ECM

 

UKMO

GFS

 

 

 

Let's compare the big 3 at T144:

 

ECM

 

UKMO

 

GFS

 

So much uncertainty and it'll all be different again in 24 hours.

Worth putting these two posts up to show how short sighted it is to look at just at Atlantic views only. When looking at the larger hemispheric views it is quite obvious that Yarmy is right and there is a lot of divergence in the mid Atlantic wrt to the angulation, strength and precise positioning of the ridge that is forecast for that area. All three have different solutions in this area which will have big impacts down the line. The only common theme is the long wave trough extending into Europe.

 

Edit - just looked at these charts again and tbh the differences are so big as to be noticed in the Atlantic charts really, but the principle still applies.

Edited November 15, 2013 by chionomaniac

[simshady]

I'm really looking forward to winter and the models tonight have not changed my outlook one bit....they have shown colder weather encroaching next week so all is looking good. Just because the heavenly charts shown yesterday are unlikely to come off it doesn't negate a winter that all we 'coldies' want.  we have a long way to go and the pattern is changing. I'm happy with things as they are now compared to a couple of weeks ago when all we seemed to be looking forward to was an endless zonal pattern..I'm optimistic

[Ian Brown]

I couldn't agree more .What makes me astonished more than the models tonight is how everybody on hear so completely waving this cold spell good bye after one bad run of models, yes they are all singing on the same hyme sheet but no different to the astonishing charts they all chucked out together this last 3 days or so.Is not quite possible that they will look completely different again in the morning?Iv just read a comment in the winter thread now claiming unless we have big strat changes in next few weeks (they obviously have no idea on what's been said today in the strat thread) then we can wave good bye to December.I have never read so much rubbish .What makes the charts any more right tonight than what they was yesterday?I fail to understand why people do this evey single year .All we no is it's getting cold. And staying cold.The professionals are talking of the possibility of prolonged cold, why the hell Ian would the bbc change there forecasts after ONE set of runs?

 

Shaun, Tuesday-Thursday is now well in the range of the models and the output now contradicts what the TV forecasts are saying. As for the Strat thread, I do feel too much importance is placed on it in some circles, but the output in recent days did go strongly against what has been the theme over there in recent weeks; a 'normal' cooling that should lead to a zonal December.

[Methuselah]

Well, what I'm hoping for - here in the Triangle of Doom - is thundery showers coming off the North Sea...

[johnholmes]

Shaun, Tuesday-Thursday is now well in the range of the models and the output now contradicts what the TV forecasts are saying. As for the Strat thread, I do feel too much importance is placed on it in some circles, but the output in recent days did go strongly against what has been the theme over there in recent weeks; a 'normal' cooling that should lead to a zonal December.

 

Ian how about giving credit to the Met Office for giving a balanced view based on a huge amount of data not just that we see and choose to use on here. If they changed every time, for example the GFS changed, then it really would be totally confusing. Just my view of course.

 

Better still Ian show the models and what they are predicting, are they all the same, of course not. So which model do you think is nearer the mark. Is it vastly different from what the outlook is on BBC TV, I never ever look at their web site for a forecast by the way?

Edited November 15, 2013 by johnholmes

[Ian Brown]

Ian how about giving credit to the Met Office for giving a balanced view based on a huge amount of data not just that we see and choose to use on here. If they changed every time, for example the GFS changed, then it really would be totally confusing. Just my view of course.

I don't dispute that John, but people make provisions when forecasts like that are given out, and although not over-hyped like something you would see in the Express, we know now that it is erroneous.

[Cecil Hogmanay Melchett]

Lovely ECM mean at 240h this evening with blocking to the NE and low pressure parked over Southern Europe.

Very nice.

[UV-RAY]

Ian how about giving credit to the Met Office for giving a balanced view based on a huge amount of data not just that we see and choose to use on here. If they changed every time, for example the GFS changed, then it really would be totally confusing. Just my view of course.

 

Better still Ian show the models and what they are predicting, are they all the same, of course not. So which model do you think is nearer the mark. Is it vastly different from what the outlook is on BBC TV, I never ever look at their web site for a forecast by the way?

Good grief can you imagine the MetO changing their summaries each time the GFS changed it's, it would make them as ridiculous  as some of the posts you see in here. Thank goodness they are professional and unbiased in their assessments and wait until they have all the relevant information at hand before making a call.

Edited November 15, 2013 by Sceptical Inquirer

[Summer Sun]

Tonight's ECM ensemble has a completely different take on things

 

Op

 

 

Ensemble

 

[Frosty.]

JH is the voice of reason, another great set of output today for the time of year, let's not forget it's still autumn for two more weeks. I see an arctic blast for the first half of next week, slowly weakening by thursday, at least for northern uk as atlantic high pressure ridges across scotland later next week with brighter but frosty conditions but continuing cold and unsettled further south and east. Then the possibility of another wintry reload by the end of next week with the cold pattern continually renewing itself well into december.

Edited November 15, 2013 by Frosty.

[Captain Shortwave]

Well here is the ECM mean for day 10

 

Completely different to this morning. 

As for this, the day7/8 time points are key which shows some form of undecutting going on into Europe leaving heights north/north east of the uk.

But the value of this mean is probably a lot less than usual due to the huge variation in the mean, let alone the operationals.

[Severe Siberian icy blast]

Shaun, Tuesday-Thursday is now well in the range of the models and the output now contradicts what the TV forecasts are saying. As for the Strat thread, I do feel too much importance is placed on it in some circles, but the output in recent days did go strongly against what has been the theme over there in recent weeks; a 'normal' cooling that should lead to a zonal December.

The output contradicts nothing. It's one set of charts . Literally . If they were to change as much as the models they won't be where they are .You've contradicted yourself Ian . The fact that we are staring down the barrel of a northerly outbreak and a very amplified pattern caused from the original pacific ridge , has helped increase the wave activity affecting the lower strat. We now have wave 2 activity in the forecast and flux going poleward into the strat which has been tropospheric led .So one one hand you say too much emphasis on the strat , then on the other hand you say because the strat doesn't support the cold spell we are now seeing the models get a grip and taking us toward a zonal December? It's a bizarre comment .The vortex is about to be put under a lot of pressure , which is reflected in the northern hemisphere forecasts .As you can see absolutely nothing zonal there is there Ian ?

[Cloud 10]

ECM 12z ensemble mean at day 10 is a bit different to its 00z counterpart with lower heights

around Greenland and more of a scandi high look about it..

 

00z..  12z..

 

 

...however,NOAA have the 00z ensemble mean as their model of the day and their

updated 8-14 day chart doesn't exactly scream zonal!

 

[Frosty.]

To be honest I think its far more important how mogreps is looking than individual op runs from gfs and ecm which could be outliers.

[SMU]

I have seen a few operationals over the years go against the mean & be wrong-  worth noting- certainly not a done deal yet-

 

The ECM would look 100% different at 240 if its misplaced the shortwave energy coming off the states- should that be travelling SE instead of NE then the block will stay intact-

 

anyway its irrelevant & will be another kettle of fish tomorrow!

 

S

[BLAST FROM THE PAST]

Ian how about giving credit to the Met Office for giving a balanced view based on a huge amount of data not just that we see and choose to use on here. If they changed every time, for example the GFS changed, then it really would be totally confusing. Just my view of course.

 

Better still Ian show the models and what they are predicting, are they all the same, of course not. So which model do you think is nearer the mark. Is it vastly different from what the outlook is on BBC TV, I never ever look at their web site for a forecast by the way?

 

The question must be asked why their website which is so promoted by forecasters is so different to forecasts John, sorry but they shouldn't be. 

 

BFTP

[MR EXTREMES]

in regards to the met office futher outlook indeed they would be very busy changing there longer range forecast but this is why I suggested wait until sunday and I for one still not convinced the ukmo model run tonight was good.

 

but the model itself is excellent so good that the other models played catch up with the ukmo.

 

the best model tonight was the jma and gem but not enough to convince me that there is not going to be complete collapse  on the horizon.

 

and as has been suggested its a very difficult pattern to maintain and things are not really in our favour on the teleconnection front either apart from a possibility of neg nao and ao but this signal must of been due to last nights ideas so im not even convinced by this.

[Catacol]

I don't dispute that John, but people make provisions when forecasts like that are given out, and although not over-hyped like something you would see in the Express, we know now that it is erroneous.

 

How on earth do we know that their current extended output is erroneous? It hasnt even happened yet. And it would be good to see some model evidence to back up your statements.