Winter Model Discussion 06Z 10/01/13>

[TEITS]

Following on from what GP said and I note the ECM control in the extended range becomes bitterly cold like last nights 12Z control run.

http://www.knmi.nl/exp/pluim/vijftiendaagse/Data/15DAAGSE_06260_NWT.png

[Weather Boy]

copied from the other thread as it may help new folk

thanks to Gibby for his outputs

For those new to model interpretation, simply read the two summaries above by Gibby. It shows quite clearly how over a 12 hour period the emphasis can change.

last evening

In Summary the cold spell is well and truly on the way. After a gradual cooling of conditions over the coming days the weather turns decidedly wintry as we move through the second half of the weekend and (as much of the output shows) much of next week too.

this morning

In Summary the stand off between GFS and the rest persists this morning. Never in the history of my model watching which in some shape or form has been over 20 years have I witnessed such a stark contrast between one model and another meaning totally different weather conditions to be experienced at the surface.

John, it's also an interesting comparison for those of us catching up.

One would think, instinctively, therefore that this is not a stand-off as such: is it not a GFS flip flop compared to a relatively steadfast ECM?

One of the very experienced (possibly professional - maybe Ian F) said that the fact that a model flips does not make it less reliable and doesn't mean its output should be binned. I struggle conceptually with that because, if it's the case that a model is showing scenario A on Monday, B on Tuesday and C on Wednesday, then what are we supposed to believe? C because it's the latest output? Are we supposed to forgett about what it said on previous days? But that doesn't make at least part of its output inherently unreliable?

Applying that thinking (even though I haven't got it clear in my head) we shouldn't be discarding the GFS for that reason. However, logically we should surely be thinking that the ECM is more likely because it enjoys a lot more support from other models. That's the way I see it anyway.

[SMU]

BIG GFS coming - low undercutting into the scandi high as opposed to going through it-

S

Edited January 10, 2013 by Steve Murr

[Wayneywoo]

You can clearly see the jet is angled differently on the 6z compared to 00z. I would like to think we will see a SSE heading LP on this run ala the ECM if the direction of the jet is to be believed?

Jet looks like it is heading to the SW coast of BI rather than Scotland...

[Timmytour]

Hazard a guess here...but GFS pushing Atlantic high a little bit further west......this could be epic! i want to see the Atlantic Swan flying north west!

[TEITS]

Could be wrong but I believe this could swing towards the ECM.

[Catacol]

Yep - at 78 GFS is sending the energy SE.

[Ian Brown]

Well certainly no climbdown from the GFS on this run.

[The Northern Ramper]

This is moving towards the ECM as predicted, unless a curve ball is thrown in the next few frames.

[R.P. McMurphy]

Could be wrong but I believe this could swing towards the ECM.

http://modeles.meteo.../gfs-0-72.png?6

No, your exactly right. As SM has just pointed out, the low is undercutting rather than going through it.

[Cloud 10]

ECM ensemble mean still very impressive in the mid-term with a very clear signal for

blocking around greenland and a cold North-easterly flow.

pressure anomalies.. 850 anomalies..

Long range ensembles show big scatter later on but still keep the mean around freezing.

http://www.knmi.nl/e....png?6767676767

[fergieweather]

Can I just clarify this suggestion "UKMO never use GFS".... to be clear, they of course analyse each NCEP run in detail and indeed their last 6-15d briefing offered considerable comparative view citing NCEP ensembles, GFS 12 & 18z runs, etc, versus ECMWF. They presently favour the latter in terms of broad outcome but equally stress the NCEP solutions as having sufficient continuity to not be ignored. So, in this current (unprecedented) situation of uncertainty, rest assured folk at Ops Centre are watching NCEP throughout each run.

Equally, I should stress that into closer MR, a key model they use for comparative analysis is ARPEGE. Indeed we have recently seen every bit as much comment and graphics from Ops Centre on ARPEGE as we have re EC etc.

[NO LONGER POSTING]

I made a prediction last week of the expected rise in temps in the stratosphere. Compare actual (left) to fcst (right) pic.twitter.com/Hr7LS7db

— Matthew Hugo (@MattHugo81)

January 10, 2013

[Paul Sherman]

Well certainly no climbdown from the GFS on this run.

Sorry I have to laugh at this Ian, I thought you might have jumped ship already as the GFS Could finally have caught onto the fact the Shortwave is following the Jet pattern.

Fair play you are sticking with the Model though

[Southender]

So so close to the undercut there.

A shift towards the EC and UKMO options for sure.

Not quite there yet, but something to clutch on to as we head into the 12's and 00's.

[Frosty.]

BIG GFS coming - low undercutting into the scandi high as opposed to going through it-

S

And its your favourite Gfs run of the day steve

Also, I would trust what GP says over anything the models and especially the gfs has been showing, every time. Next week does look cold and cyclonic with a lot of snow potential.

[Wayneywoo]

Again, T+72 - T+96 is the period to watch as far as the GFS is concerned. The angle of the Jet on the 6z is very different to the 0z. As this time period gets closer so the GFS appears to be changing it's thoughts ever so slightly...

[Snowly does it]

Might be just me but I don't see it. Looks to me like the shortwave won't make it through? I'm at T96

[weatherguy]

Yep - at 78 GFS is sending the energy SE.

Well certainly no climbdown from the GFS on this run.

Picking 2 random posts and it's no wonder that "newbies" can get confused on here, differing opinions are fine but it would be helpful if you could back up what you say with a chart and some analysis.

So i'm not a hypocrite here's my take at this time frame:

Current run from GFS:

Previous run:

The position of that low certainly indicates that it is sending more energy south east than the previous run and may well be breaking through that belt of high pressure over the north sea near scandy. Too early to tell if it's doing enough however.

Edit: Moving the frames on and it refuses to send the low SE, that low tracks NE instead...Minor improvement but not enough.

Edited January 10, 2013 by weatherguy

[nick sussex]

The GFS refusing to backdown.

I think whats a bit frustrating is that if its going to not take that shortwave near Iceland se/s then it might aswell take it east and prolong the initial easterly.

Here its the middle ground solution which shortens the cold advection from the east and still wont deliver what the UKMO suggests.

[The Northern Ramper]

And there is the curve ball, it thought about the undercut and then decided against it :s

[kold weather]

While it is closer, I'd hardly say its fallen in line, its still pretty much going down its own route by 96hrs.

Pattern flattening out rapidly by 102hrs, so still different from most models...

[lord stratus]

The GFS refusing to backdown.

I think whats a bit frustrating is that if its going to not take that shortwave near Iceland se/s then it might aswell take it east and prolong the initial easterly.

Here its the middle ground solution which shortens the cold advection from the east and still wont deliver what the UKMO suggests.

Nick, the weather doesn't work that way

[Paul Sherman]

Well GFS Sticking to it's guns and it's amazing consistency with the Modelling around the Iceland area.

I said this in the regionals and maybe Ian F Can answer this, any chance the others have the angle of the Jet Modelled wrongly ??

Truly amazing differences at such a short timescale in Model Watching!

One thing for sure though this weekend is starting to look more and more interesting, more especially Sunday!

[Beast of Plympton]

Im a newbie here, looking at the models but don't really understand them to much at the moment!

Can I just ask the more experienced is this looking better then the 0z so far?

Thanks

Ian