Model Output Discussion - 26th December - 1st January

[shedhead]

Well it would be nice if certain people didn't nitpick all the time. How am I misleading people when I posted that chart as it shows that temperatures could get up to 14C which is quite noteworthy for January? Generally throughout the run it will be mild - yes cooler at times but only dropping to average which is still mild for most places.

And what about all the misleading posts showing the cold charts in FI that will never happen.. of course this thread is cold biased in the winter so It's a lose lose situation, but it would be nice if some people had some perspective rather than constantly looking for cold and ignoring the reality

Then it wouldn't be the MDT thread Rob...

All joking aside I'm sure most people can see the point you are making, there is no real point in not posting the mildest chart, if you are trying to demonstrate how mild it could possibly be. Once again this highlights precisely what has been, still is and probably always will be the problem with the MDT, ie those posting charts showing mild senarios will get vilified, even though they are fully justified in doing so. You might expect it from ordinary members, but Regional Forum Hosts should really know better.

Edited December 29, 2011 by shedhead

[The PIT]

Not sure about the AO GSL. Seems to be a lot of scatter and could go any direction. The NAO is very slowly shifting to neutral as you say.

[Harsh Climate]

Awful charts at the moment welcome to a typical english winter!

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

Even though the NAO shows a chance of it eventually heading below neutral, who's to say if that's correct a day later it shoots up to positive again lol

AO is pretty poor aswell.

For a real good cold/snowy spell from the east/ north east you need the Nao below around -2 and the AO below -3. Not exclusively but around that.

[Frosty.]

This chart sums up the Gfs 06z for me, it's a really desperately poor run for cold prospects yet again and it shows mild then cool then mild etc for the full 384 hours, there is a mini cold snap in the north next monday with wintry showers and strong westerly winds but it soon turns milder again. The latest meto update has minor tinkering within the wording but the general pattern is the same all the way to the end of january with no cold weather expected apart from brief nw'ly showery interludes.

Edited December 29, 2011 by Polar_ Low

[shedhead]

This chart sums up the Gfs 06z for me, it's a really desperately poor run for cold prospects yet again and it shows mild then cool then mild etc for the full 384 hours, there is a mini cold snap in the north next monday with wintry showers and strong westerly winds but it soon turns milder again. The latest meto update has minor tinkering within the wording but the general pattern is the same all the way to the end of january with no cold weather expected apart from brief nw'ly showery interludes.

What chart PL?

[Frosty.]

What chart PL?

sorry it was this one..really worth waiting for

[MR EXTREMES]

well i ive been watching the model thread with great interest whilst flicking from tec thread strat thread and cycle24 website.

and its certainly clear that la nina and increase in solar activity are clearly having a fair effect on our weather right now!.

but whats intrested me the most is the last week or so a flurry of activity between here and the tec strat thread,

in here ther has been a few days of all models toying with a more blocked period mid january although nothing has come with in the realiable period theres been a few days were some good outputs were being shown,

id expect thease good outputs to return withing the next ten days.

with perhaps better runs even as soon as this evening.

its far to easy to expect one run this morning to throw a spanner in the works but confidence has been with the models on a more cooler colder outlook beyond jan 10th.

as for any lrf things change fast and this will only help gp look at the reasons to what caused a fail in his lrf,

but u can be sure that a cold spell will grace our shores and i would not be suprised if feb and march turn out the coldest two months.

[Grimsby Snow Lover]

Awful charts at the moment welcome to a typical english winter!

http://www.cpc.ncep....a/nao.sprd2.gif

Even though the NAO shows a chance of it eventually heading below neutral, who's to say if that's correct a day later it shoots up to positive again lol

AO is pretty poor aswell.

For a real good cold/snowy spell from the east/ north east you need the Nao below around -2 and the AO below -3. Not exclusively but around that.

Im not sure if you have been following the NAO/AO charts over the past month or so HC but they are both looking much better than they did two weeks ago regarding a shift to more neutral/negative values. The AO especially was forecast to be very positive with no runs anywhere near the neutral line. The fact that we are now in that forecasted period from 2 weeks back I would say it has verified well as the Arctic especially is still very positive, so whats to say in a few weeks time the Arctic oscillation might well turn out to be more neutral as currently I would say 1/3 to 1/2 runs suggest this.

Edited December 29, 2011 by Grimsby Snow Lover

[Frosty.]

I don't think it matters whether the 6z was a mild outlier or not, most of the experts seem to be tearing up their original LRF's as they made a pigs ear of it, 10/10 for trying though! they now say it's going to be mild or average or both, anyone who follows the models can see that for themselves!

[Cheese Rice]

Theres nothing in the models to suggest any cold from our east or north east. So far there is no pattern emerging on the GFS ensembles other than current zonal. So what I would really appreciate is when members harp on about cold coming mid/late Jan they back it up with some sort of evidence.

[Paul White.]

I don't think it matters whether the 6z was a mild outlier or not, most of the experts seem to be tearing up their original LRF's as they made a pigs ear of it, 10/10 for trying though! they now say it's going to be mild or average or both, anyone who follows the models can see that for themselves!

And the moaner of the winter awards goes to ???!!! Come PL it's only december. Who is tearing up their lrf's? it would be madness to do so now, that's like buying a lotto ticket for Saturday and tearing it up tommorow (Friday) . You have been around this forum and reading charts for quite a long time from what I remember. For me until GP writes in this or another thread and explains that his lrf has has gone wayward then I see no reason to be despondent. And bizarrely I write this as a heavy hail storm with high winds passes over Huddersfield.

Regards

Paul

[bobbydog]

dont worry, snow is coming soon. the model i'm watching is the Volvo XC70 AWD '01 model, sitting on my driveway with a very sick gearbox-

cue- copious amounts of snow!

[Dale Leigh_6487]

off topic i know but horrendous hail and severe wind here in hyde cheshire. lots of fences blown out etc was this forcast? lets hope the modela improve soon.

[stewfox]

Of course it's worth noting things can change very quickly indeed

How many people who post on here recognise such a comment ? We have now gone to 17th Jan as date dailed before even a chance of a pattern change !

A few cold outliers in F1 yesterday have now been dropped and its straight back to winters over.

If they reappear tonight will it be back on.

[yido]

Perhaps not the best place for this but in response to some of the points on LRF's how can they be revised now for winter? Surely the Jan part of a LRF would be linked to the Dec part. If that is wrong then the whole thing is wrong? You can't have Jan correct if it follows from a December that was wrong as that's surely nothing more than coincidence?

[mountain shadow]

Crikey, virtually a whole page of off topic posts...........inluding this one.

[J10]

Just a reminder that this is a model discussion thread not a model prediction thread.

As such no one can say Winter is over, or that February will be a snow fest, and if you can say so please back up it up with meaningful charts rather than a hunch.

[SnowBallz]

I don't think it matters whether the 6z was a mild outlier or not, most of the experts seem to be tearing up their original LRF's as they made a pigs ear of it, 10/10 for trying though! they now say it's going to be mild or average or both, anyone who follows the models can see that for themselves!

An 'expert' who tears up their forecast, isn't really deserving of the term 'expert', in my humble opinion.

I honestly don't understand that bit. Personally, when I 'forecast' something, I stick to it. I don't change it as it turns out I'm wrong, because - if that's acceptable - then what's the point of 'forecasting' anything; because anyone can do that!

Those false prophets whom scrap their 'forecasts' would do better to re-analyse their original data, and see where it was that lead them to make false assumptions and thereafter, predictions. Scientifically, this would be a more productive, constructive and progressive approach to the science which we're dealing with here.

As for the models of late...

I think the problem is that, although a pattern change has been mooted amongst discussions, I don't think that it's a change which is likely to filter through into model algorithms over night. It simply doesn't work like that. So, to those eager to see such rapid change, I would urge caution and patience. For, otherwise, you're falsely amplifying an inference which, for example, GP proposes. GP supposes a change, but you're ignoring the context and caution which he's wrapped around that conceivable change. That's wrong, and that - I believe anyway - it why there is a lot of glum faces, as each revolution of the models are output. Currently, anyway.

I personally think the various models are only going to start showing notable changes in runs which take place in the 2nd week of January. Why? Simple: the upstream pattern - which is theorised - will then be within a more mathematically sound range, and the calculations which are run on that dataset will have a sounder footing. Personally, I tend to avoid GFS as its verification evidence proves it is not a reliable model. That said, others are more than free to follow it's daily runs if they so wish, but - again - I would urge caution when, especially, looking into 'FI' on it. Last winterr, I found that BOM had a good handle on upstream signals, and you must always weight both ECMWF and UKMO, as their concentration, patterning and resolution is preferable over the GFS - that's just plain common sense really.

CFS is quite fun too. I'm currently writing a paper on its performance as a case study - great fun

Happy Model Watching gang

[Cecil Hogmanay Melchett]

GFS 12Z brings pockets of 10deg 850 into the flow as we drag up some deeps South westerlies in the 1st week of Jan- courtesy of a 1040mb strong cell of high pressure pressure centered just to the north of spain.

[johnholmes]

GFS 12Z brings pockets of 10deg 850 into the flow as we drag up some deeps South westerlies in the 1st week of Jan- courtesy of a 1040mb strong cell of high pressure pressure centered just to the north of spain.

are you on a wind up?

it also shows deepish temporary cold air and a pretty deep depression over the same time scale.

I love short lived cold and snow and in spite of that I do try to post objectively; but I do wish some of you would, give the chart you are quoting as an example and also SAY its one chart out of one run and not lead the less knowledgeable to wonder what you mean?

If I had time I would illustrate your comment and also the other charts from the 12z GFS run that show a different set up-but time presses.

Edited December 29, 2011 by johnholmes

[shedhead]

GFS 12Z brings pockets of 10deg 850 into the flow as we drag up some deeps South westerlies in the 1st week of Jan- courtesy of a 1040mb strong cell of high pressure pressure centered just to the north of spain.

Yes indeed HD, without question IF this chart were to verify we'd be looking at widespread 11-13c, with a 14 or 15c possible somewhere, much as robthefool suggested earlier. No real changes across the 12GFS high res part of the run, but no real surprises there, however the lower res end seems keener to build heights a little farther north once again allowing colder air to plunge in E Europe.

are you on a wind up?

it also shows deepish temporary cold air and a pretty deep depression over the same time scale.

I love short lived cold and snow and in spite of that I do try to post objectively; but I do wish some of you would, give the chart you are quoting as an example and also SAY its one chart out of one run and not lead the less knowledgeable to wonder what you mean?

If I had time I would illustrate your comment and also the other charts from the 12z GFS run that show a different set up-but time presses.

Why would you ask him if he's on a 'wind up' John, he is absolutely right in what he says?

Edited December 29, 2011 by shedhead

[johnholmes]

Yes indeed HD, without question IF this chart were to verify we'd be looking at widespread 11-13c, with a 14 or 15c possible somewhere, much as robthefool suggested earlier. No real changes across the 12GFS high res part of the run, but no real surprises there, however the lower res end seems keener to build heights a little farther north once again allowing colder air to plunge in E Europe.

Why would you ask him if he's on a wind up John, he is absolutely right in what he says?

final post while I find another life and get some dinner.

Of course he is right-but one chart as I said, nor did he show the chart or link to it (neither did I for that matter-although I've posted what I consider some constructive posts into Net Wx today), he could just as easily have shown something which did not suggest such mild air.

All I ask is that we all show some common sense and realism and stop posting single charts from single runs and making out that is what is going to happen through the whole run, short or FI.

[Cecil Hogmanay Melchett]

are you on a wind up?

it also shows deepish temporary cold air and a pretty deep depression over the same time scale.

I love short lived cold and snow and in spite of that I do try to post objectively; but I do wish some of you would, give the chart you are quoting as an example and also SAY its one chart out of one run and not lead the less knowledgeable to wonder what you mean?

If I had time I would illustrate your comment and also the other charts from the 12z GFS run that show a different set up-but time presses.

What on earth are you talking about?why would i be on a wind up?Does the 12zgfs drag up some very mild south westerlies or does it not?

OK lets generalize,12z gfs is,in the main,a run dominated by south westerlies,is that better?

Edited December 29, 2011 by happy days

[Brum Watcher]

another poor run from GFS all the way to the end....MILD is the trend...lack of potential for and 0 uppers never mind -5's.

[bluearmy]

re the parallel gefs currently visible on meteociel (the gfs op runs at 27km horizontal resolution for comparison out to T192).

b. Global Ensemble Prediction System (GEFS)

Major upgrade planned for February 2012.

Yuejian Zhu presented plans. The GEFS upgrade will include:

-using current operational GFS

-increase in horizontal resolution from 70 km to 55 km (T254) for 0-192 h, and 70 km (T190) for 192-394 hours

-increase in vertical resolution from 28 to 42 layers for 0-384 hours

Improvements in the mean and probabilistic verification were shown. A warm bias in the operational GFS is also evident in the GEFS and could be improve via bias correction.

Given that the GEFS will impact the NAEFS, a analysis of the impact on NAEFS may be necessary.

While the individual ensemble member data will be 20 minutes later than at present, the probability products may be as much as 5 minute earlier.

the gfs op runs at 80 km horizontal resolution beyond T192 but at 64 layers so its open to debate whether the gefs would be a more reliable tool post T192.

Edited December 29, 2011 by bluearmy