Model Output Discussion: 12Z (02/12/12) And On...

[bluearmy]

Ah: but that risks leaving faith only in the output solutions that favour any personal biases (e.g. wanting cold)... and that's poor science!! Objective and impartial comparison the only valid route, I hope (on this thread at least!!).... we see too much guff about "poor runs"; "bin this or that run"; etc etc. The weather will be what it will be.

Steady ian - you were making so many friends aswell !!!!!!

Its ok - you can use this place as 'coldies anonymous'. We wont tell anyone.

Wrt to the extended gefs, there seems to be a trend for heights to be dropping across the polar NH as week 2 progresses. This could well be the low res part of the suite responding to the movement of the vortex from canada to siberia and struggling to resolve this.

[nick sussex]

Ah: but that risks leaving faith only in the output solutions that favour any personal biases (e.g. wanting cold)... and that's poor science!! Objective and impartial comparison the only valid route, I hope (on this thread at least!!).... we see too much guff about "poor runs"; "bin this or that run"; etc etc. The weather will be what it will be.

You should get used to the thread after a while, generally in winter a poor run is one that doesn't have good snow potential, occasionally its also used to describe a cold but dry run!

Sometimes though Ian you would agree that a certain output might look suspect or out of kilter with the rest of the guidance.

I'm not saying that about tonights UKMO as its probably got some ensemble support, the UKMO is as much a victim of only going out to 144hrs, it has no chance of redemption with a better 168hrs chart! hence it suffers in here!

[The watcher]

Ah: but that risks leaving faith only in the output solutions that favour any personal biases (e.g. wanting cold)... and that's poor science!! Objective and impartial comparison the only valid route, I hope (on this thread at least!!).... we see too much guff about "poor runs"; "bin this or that run"; etc etc. The weather will be what it will be.

Here here, I hope some take heed of this.

We should all have learnt lessons from last week that not "one" run can be assumed right on the basis of it showing more cold than others.

Over the years on Netweather I have seen the verification stats change quite often between UKMO, ECM and GFS leading the way at times, so it is a bit futile bringing these up. We should be looking at the top 3/4 models as a whole and seeing what agreements they lead to with eachother. No point having a team of models if we don't use them together to see what is nearer the mark.

[A.J]

can someone define a "poor run"?

yes in 2 main points...

1) 'Poor run' as in a output run where after a certain timescale the output predicts implausible synoptic patterns when compared with most recent output snapshot i.e the output at, for example, T144 bares absolutely no relation to the predicted synoptic patters at T132, in essence, possible data errors lead the subsequent output 'up the garden path'

or, based on what we normally see in this thread

2) 'Poor run' as in an output run when the predicted synoptic pattern DOES NOT meet the requirements for the originating posters favourite type of weather!

[bluearmy]

I've been through the contol perbuatations for the GEFS +12z and there is only one that I can see of offering severe winter weather (i.e. -8 805 temps). The remainder all flirt in the 0 to -4 range most of the time indicating continuation of cool weather (similar to today). This will bring the CET down for December (assuming notihng above average thereafter), but presumably won't satify those who would see a 30cm+ dentritic snow, often. A blacked Atlantic may be showing, but our position on the boundary to continental weather remains.

Its not all about uppers with an easterly tim. there looked to be three or four cracking solutions to me post T192 and the control is pretty well the best option available n the longer term.

[IDO]

Well the control is my run of choice today:

http://modeles.meteo...-0-1-384.png?12

http://modeles.meteo...-0-0-384.png?12

Gets my IMBY easterly. But the Op goes another way. The GEFS:

http://modeles.meteo...ndres&runpara=0

Well its one step forward and two back. No clear signals from that. Still no trend for sustained very cold weather though good agreement on a 5-7 day cold period after T168, so maybe something like that will follow after.

Edited December 2, 2012 by i'm dreaming of...

[AWD]

BOM not far from the GFS at T192;

http://www.meteociel.fr/modeles/bome_cartes.php?ech=192&code=0&mode=0&carte=1&archive=0

Heights ridging along eastern Greenland & a deep trough over Eastern UK

[Snowy Easterlies]

I think the lack of comment on the 144hrs UKMO says it all

A poor run imo, let's hope the gfs has spotted a new trend

In general I think the gfs is leading the charge this Winter and the UKMO has temporarily reached the cannon fodder!

it will be sods law if UKMO was right this time after that cock up it made when it was showing cold and snow a week a go only for it to implode at the last minute

Edited December 2, 2012 by Snowy Easterlies

[Bobby]

Let's be clear, we are a long way from firming up on a proper cold snowy spell at the moment. The real cold charts are well out into FI and there is significant uncertainty and volatility in the OP runs and ensembles even at shortish-medium range. Just so people don't get thinking we're nailed on for a big freeze like the last time. At the moment it's potential, potential I hope comes true. But there are huge range of possible outcomes at the moment. When we get OP and ensemble agreement at say +120 / +144 then it's time to get a bit more excited.

Looking through the ensembles there's a huge variety of options shown, not all of them good.

One them though that's interesting is that Wedneday/Thursday low, a lot of the ensemble runs give a possible significant now event if it comes off just right.

i.e.

(a few more too)

One to keep an eye on.

Not too far away either.

[chris55]

PS as of 2 yrs ago, Ops Centre no longer bother providing us with their T+144 GM prognosis, which says everything about their view on how fruitless it is examining that sort of stuff beyond that timescale (as rightly suggested above by another poster). Sticking with EC & MOGREPS is the way of things into timeline beyond that.

Ian why don't the public get to see said charts? With some 160 million coming out of the public purse (the majority of the METs budget) it's actually quite annoying that the info is not available to us mere mortals. Is it the commercial arm of the MET that stops such info being widely available?

[Frosty.]

Its not all about uppers

Theres a lot of uppers and a few downers on here this evening

I still think there is enough evidence to support a prolonged cold further outlook but until then it's the far north and east (NE Britain) which looks most wintry at times in the week ahead but occasionally cold further south and it's only tomorrow which could be described as mildish in the south.

[Eskimo]

Let's be clear, we are a long way from firming up on a proper cold snowy spell at the moment. The real cold charts are well out into FI and there is significant uncertainty and volatility in the OP runs and ensembles even at shortish-medium range. Just so people don't get thinking we're nailed on for a big freeze like the last time. At the moment it's potential, potential I hope comes true. But there are huge range of possible outcomes at the moment. When we get OP and ensemble agreement at say +120 / +144 then it's time to get a bit more excited.

Looking through the ensembles there's a huge variety of options shown, not all of them good.

One them though that's interesting is that Wedneday/Thursday low, a lot of the ensemble runs give a possible significant now event if it comes off just right.

i.e.

(a few more too)

One to keep an eye on.

Not too far away either.

Can you post a link to all the other perturbations please?

[ukpaul]

BOM has the same mid/long term problem as the GFS 12z, we get a system over us with barren northerlies and 850's warmer than most would need for snow. An evolution linking those heights either side and getting us a proper E/NE flow may happen out of that it'd end in more frosty weather if nothing else.

[Isolated Frost]

A lot of trust being placed on the Operationals again- calm from them, take a look at the H5 anomalies, strat and ensembles for a broader look and more precise look at things. If I were to weight things for a medium-term forecast I would say:

Ops 10%

H5 30%

Ens 30%

Strat 30%

Wait and see for the solutions to get there, but high pressure over Scandinavia looks the most realistic outcome eventually, the way we get there is under question... -3c here now, so plenty cold already, so lighten up those who aren't so!

[Mr Frost]

Let's be clear, we are a long way from firming up on a proper cold snowy spell at the moment. The real cold charts are well out into FI and there is significant uncertainty and volatility in the OP runs and ensembles even at shortish-medium range. Just so people don't get thinking we're nailed on for a big freeze like the last time. At the moment it's potential, potential I hope comes true. But there are huge range of possible outcomes at the moment. When we get OP and ensemble agreement at say +120 / +144 then it's time to get a bit more excited.

Looking through the ensembles there's a huge variety of options shown, not all of them good.

One them though that's interesting is that Wedneday/Thursday low, a lot of the ensemble runs give a possible significant now event if it comes off just right.

i.e.

(a few more too)

One to keep an eye on.

Not too far away either.

I think as this is a UK weather forum I will just add in that IMBY I have had a permanent ground frost day/night from Tuesday morning. Heavy snow forecast for tonight lasting well into the early morning period.

Real cold charts have happened this week, quite a potent cold spell indeed. (Even for Scotland at this time of year)

Still no sign in the foreseeable for anything mild IMBY.

Edited December 2, 2012 by Mr Frost

[weather eater]

We could look at any of the models and any or none of them maybe onto the correct evolution, but for me at lest the GFS is consistent, obviously small changes will make a big difference to the type of weather that we receive and post mid-range a variety of easterly options have been shown. While there are no guarantees I would rather stick with the consistent model as the way forward as opposed to those models that are changing from run to run.

[lorenzo]

Meanwhile on the ECM looking a lot cleaner within the 5 day mark as the vortex completes reformation across the polar field.

Recalling previous runs ECM painfully slow with this and GFS UKMO quicker to resolve this, a more definitive path coming up from the ECM.

Edited December 2, 2012 by lorenzo

[Timmytour]

Thursday represents 31 years to the day that one of my favourite winters got going.

If the models can evolve to show this for thursday I'd be happy....and I don't think they are a million miles off doing so..

[TEITS]

Excellent ECM at +144 and if you compare with the rest of the 12Z model runs this is fairly representative of all the model output.

http://www.wetterzentrale.de/pics/Recm1441.gif

Key now is this must move SE. We don't want this sitting around the UK flapping like a budgie.

P.S UKMO is fine BTW.

[Continental Climate]

the polar vortex looks like its getting nice and punctured here http://www.meteociel.fr/modeles/ecmwf/runs/2012120212/ECH1-144.GIF?02-0 and only at 144!!

It truly cant be long now before something notable turns up in the models that will make this current cold spell seem like a walk in the park, something has got to give soon!!

[Jonan92]

Can we say that GFS has lead the way with that Greeny? ECM showing something similar to GFS's idea

[chris55]

GEFS ens still with the possibility of something quite interesting for Thursday, about 8 out of 20 bring in snow for parts of England.

p12 best for the snowy slider,

P19 not so interesting,

Overall little support for the really snowy option but one to watch and if were very lucky p 12 could be on the money.

[fergieweather]

Ian why don't the public get to see said charts? With some 160 million coming out of the public purse (the majority of the METs budget) it's actually quite annoying that the info is not available to us mere mortals. Is it the commercial arm of the MET that stops such info being widely available?

I think it's because they wouldn't want to see model discussion forums getting over-excited at sight of their astonishing suite of model products ;-)

No, seriously: yes, commercial interests dictate, but then it wasn't that long ago they allowed raw NAE onto websites. Doubt we'll see MOGREPS, UK4, UKV, UKPP and the other goodies on web at any time, however.

[cooling climate]

I'm afraid that's complete tosh Kold.

I presume you wouldn't see a cold spell coming from this chart either then

http://www.wetterzentrale.de/pics/archive/ra/1947/Rrea00119470118.gif

I doubt anyone would of guessed what was around the corner from that chart.

The chart for three days before that on the 15th look truely awefull,it just

goes to show you can never tell. Although as I said before the UKMO t144 chart

has potential written all over it.

ECM out to t144 and its looking like we could have a cracking run to come.

[Jason H]

... We don't want this sitting around the UK flapping like a budgie.

The models look broadly similar upto this stage now. What happens next is the interesting bit. Which as always is outside of the reliable.

Edited December 2, 2012 by Jason H