Model output discussion - 1st December onwards

[northwestsnow]

GEFS 12z look to have quite a few tasty members

Fascinating model watching at last - eyes down for a lovely ecm to end the evening.

[johnholmes]

Been unable to watch the model drama very well with no web connection for 48 hours.

I would be very grateful if one of you bright chappies/chappesses could give me a BRIEF outline of where we are. Reading some comments above it might well help some of our newcomers and visitors as well. Concentrating on the next 120-144 hours really. I can do my own playing beyond that now I can see the anomaly charts, which do look interesting with heights across northern latitudes and troughs south of this going well into Europe, especially with the version from ECMWF-GFS, be interesting to see if NOAA 6-10 trends more this way this evening.

Edited December 29, 2015 by johnholmes

[Duane S.]

As is normally  the case, there are 2 ways of viewing the charts, take the 12z GFS Op as very much case in point.

1) At face value.

This will bring disappointment if you are looking for cold in your back yard.

 

2) With the bigger picture in mInd.

In order to get to sustained cold to the UK from where we currently are, we would (in all reality) need to go through a transitional period where the building blocks are laid, aka the dismantling of the vortex, HLB setting up in the Northern Hemisphere, a better aligned jet, vortex displacement etc. 

From there lies the true potential, no certainties by any stretch of the imagination but instead of needing to roll a double 6 we could get away with rolling a, say, 8,9,10,11 OR 12.

i.e. No matter how good the background signals and NH profile in terms of copious amount of ridging and blocking, we will ALWAYS need a bit of luck.

Best we can ever do is reduce that element required to as low as possible.

Edited December 29, 2015 by s4lancia

[blizzard81]

11 minutes ago, fergieweather said:

Yes, still caution advised on where this ultimately travels.  As UKMO note (in briefing earlier today about this unfolding situation early Jan), the dichotomy of GFS versus other deterministic models is all the more eye-catching this occasion because - as Exeter puts it - "....it (GFS) is often the least progressive of the main models...".

(Emphasis on 'least')!! 

But ECM has also been progressive the last couple if runs.

[phil nw.]

22 minutes ago, knocker said:

As an overview the gfs is showing an Atlantic dominated scenario with bouts of wind and rain traversing the UK, powered by a strong jet stream, with temps around average, maybe even a little above for much of the time. There is no other way of viewing it unless you are wearing snow goggles.

Got to say Knocker pretty much agree-cold rain instead of mild rain for most of us was my first impression of the GFS.

UKMO has the trough disruption better angled for those further north to see some snow possibly, especially anywhere with elevation.

Overall though the trough is too far north and the deep cold remains across the north sea.

 

 

 

[knocker]

11 minutes ago, s4lancia said:

As is normally  the case, there are 2 ways of viewing the charts, take the 12z GFS Op as very much case in point.

1) At face value.

This will bring disappointment if you are looking for cold in your back yard.

 

 

I would like to emphasis, in case there is any misunderstanding, that my post above was just an overview of the gfs ops run, no more no less, in an attempt to clarify the position for newbies who quite understandable get confused by the one line soundbites posted during the progress of the run which by definition cannot be an accurate assessment. I was in no way attempting to put it into context regarding the future evolution which is a far more complex issue.

Edited December 29, 2015 by knocker

[northwestsnow]

2 minutes ago, knocker said:

I would like to emphasis, in case there is any misunderstanding, that my post above was just an overview of the gfs ops run, no more no less, in an attempt to clarify the position for newbies who quite understandable get confused by the one line soundbites posted during the progress of the run which by definition cannot be an accurate assessment. I was in way attempting to put it into context regarding the future evolution which is a far more complex issue.

You seem to have missed out the UKMO run in your analysis knocker  

[nick sussex]

7 minutes ago, Mucka said:

That's a surprise. I think the general sentiment portrayed on this forum is GFS is among the most progressive.

We have seen verification stats that show GFS is behind the Euros, do the MetO give any extra weight to the Euros when they are similar but divergent from GFS?

 Take it from me, I've read every daily medium and extended discussion for the last ten years over the winter months. And at least for the last 5 years the State forecasters which often go into more detail. Theres no question at all of the progressive bias of both the GFS/GEFS. And given that it comes from the horses mouth in terms of NCEP criticizing their own model then I'm confident that's the case.

[Mucka]

Just now, nick sussex said:

 Take it from me, I've read every daily medium and extended discussion for the last ten years over the winter months. And at least for the last 5 years the State forecasters which often go into more detail. Theres no question at all of the progressive bias of both the GFS/GEFS. And given that it comes from the horses mouth in terms of NCEP criticizing their own model then I'm confident that's the case.

I actually believe that to be the case too and I have read all your NCEP discussion posts , i was being diplomatic. 

[chrisbell-nottheweatherman]

1 minute ago, nick sussex said:

 Take it from me, I've read every daily medium and extended discussion for the last ten years over the winter months. And at least for the last 5 years the State forecasters which often go into more detail. Theres no question at all of the progressive bias of both the GFS/GEFS. And given that it comes from the horses mouth in terms of NCEP criticizing their own model then I'm confident that's the case.

Evidently the Met Office don't agree.  I must admit, I'm a touch underwhelmed by the short-term at present, given the possibility of more heavy rain for the north, though the models seem to agree on a fairly dramatic hemispherical pattern-change.

[knocker]

1 minute ago, northwestsnow said:

You seem to have missed out the UKMO run in your analysis knocker  

Now Now, you know very well I was answering a query specific to the GFS. For a minute there I thought you were suggesting selective bias which, of course, you know I would never be guilty of.

[northwestsnow]

3 minutes ago, knocker said:

Now Now, you know very well I was answering a query specific to the GFS. For a minute there I thought you were suggesting selective bias which, of course, you know I would never be guilty of.

I noticed that you very rarely if ever comment on the ukmo model, just an observation - maybe you dont rate the model...

 

Edited December 29, 2015 by northwestsnow

[tight isobar]

^^ gfs notorious 'most' progressive/westerly mobile based output. 

Its 6zsuite pick of the bunch for over-progression. 

[Eskimo]

Eyes down for yet another crucial ECM 

[nick sussex]

Just now, chrisbell-nottheweatherman said:

Evidently the Met Office don't agree.  I must admit, I'm a touch underwhelmed by the short-term at present, given the possibility of more heavy rain for the north, though the models seem to agree on a fairly dramatic hemispherical pattern-change.

No disrespect to the UKMO but they're wrong. Unless the NCEP forecaster decided to criticize the GFS and GEFS because he or she was having a bad day then I can only go on what I've read. I've probably read more of the discussions about the upstream pattern from NCEP than the UKMO team. They're more interested in their own models and the ECM anyway.

[northwestsnow]

Latest FAX chart 72.

Interesting.

[johnholmes]

how about IF it will allow me to show Extra 850 mb Temperatures and isobars (the white lines) folk make up their own minds?

I hope this can be allowed please Paul/team, just this once.

It might help visitors/new folk see what the latest GFS is suggesting?

My own view is that no sooner does it bring in lower 850 temperatures than the next surface system swings in with less cold air. Through most of its run it shows the isobars are from west to south west, rarely north west, so snow prospects away from hills and the far north look slight to me. Probably non existent for any lasting/lying variety, although the Scottish ski resorts should do quite well.

no not allowed to run it but try the free version of a similar thing.

link below

http://www.netweather.tv/index.cgi?action=nwdc;sess=

Edited December 29, 2015 by johnholmes

[tight isobar]

Again the Ecm looking good for a possible route -via- continental cooling advection. 

At mid point run.

[shaky]

Ecm same as ukmo at 96 hours!!!scandi high backing west!!

[Mucka]

13 minutes ago, johnholmes said:

how about IF it will allow me to show Extra 850 mb Temperatures and isobars (the white lines) folk make up their own minds?

I hope this can be allowed please Paul/team, just this once.

It might help visitors/new folk see what the latest GFS is suggesting?

My own view is that no sooner does it bring in lower 850 temperatures than the next surface system swings in with less cold air. Through most of its run it shows the isobars are from west to south west, rarely north west, so snow prospects away from hills and the far north look slight to me. Probably non existent for any lasting/lying variety, although the Scottish ski resorts should do quite well.

http://www.netweather.tv/secure/cgi-bin/premium.pl?action=gfslite;sess=65e9c3ddcd0318c5f324994c9fa4f7ec

no not allowed to run it but try the free version of a similar thing.

 

I'm not sure there were any posts suggesting GFS would bring snow to low land England John, just that it was an improvement over its previous output in hi res and move toward the Euros.

Edited December 29, 2015 by Mucka

[gottolovethisweather]

I haven't caught up with all that has been said about the GFS 12z and the UKMO equivalent but this isn't a bad chart within the realms of the reachable and achievable.

Furthermore I had previously alluded to this snow risk in a past post, so worth considering should you be out and about when seeing the New Year in, please do also take a glance up at those lamp-posts.

The post in question complete with obligatory Fax Chart.

 

Edited December 29, 2015 by gottolovethisweather

[BLAST FROM THE PAST]

18 minutes ago, northwestsnow said:

Latest FAX chart 72.

Interesting.

That looks like the UKMO model's take on it...good start

 

BFTP

[BLAST FROM THE PAST]

8 minutes ago, tight isobar said:

Again the Ecm looking good for a possible route -via- continental cooling advection. 

At mid point run.

That LP lobe over Iceland needs to dissIppate

 

BFTP

[Mucka]

ECM 144 comparison.

It sits somewhere between UKMO and GFS as far as cold prospects go.

[shaky]

Ecm 144 hours not as good as ukmo but not as bad as gfs!!!low pressure still slamming into central europe and heights increasing to our north!up to 120 hours it looked identical to ukmo which can only be a good thing!!