Model output discussion - 1st December onwards

[Southender]

Well, you can't blame a man for trying.... 

http://modeles.meteociel.fr/modeles/gfs/runs/2015120406/gfs-0-300.png?6

http://www.wetterzentrale.de/pics/archive/ra/2010/Rrea00120101218.gif

[Ali1977]

Can't post pictures but the GFS control has a pretty good FI too....As things start shaping up at day 10 the ECM, and GEM need to get and stay on board.

knocker, as you are not a coldie like most of us - can you see things changing considerably this side of Xmas? Ian F if your watching, what do you think? White Xmas???

Edited December 4, 2015 by Ali1977

[MPG]

10 minutes ago, Ali1977 said:

Can't post pictures but the GFS control has a pretty good FI too....As things start shaping up at day 10 the ECM, and GEM need to get and stay on board.

knocker, as you are not a coldie like most of us - can you see things changing considerably this side of Xmas? Ian F if your watching, what do you think? White Xmas???

Going by what's on offer in FI and the charts Knocker has posted, it seems that the north could be seeing a more of NW influence into mid month but with lower 850 temps and wintry ppn to lower levels. As for the south more westerly than NW but much cooler with wintry ppn to the hills. Cant see anything proper northerly.

Edited December 4, 2015 by MPG

[Paul_1978]

1 hour ago, tight isobar said:

This morning s suite leaving a lot to ponder mid month onwards. ....

I think its almost nailed foe a mid month pattern change...perhaps in a more notable way than some suspect! !!

Some interesting output.

"Almost nailed" is a bit premature... :-/

[nick sussex]

A bit more in relation to the discussions in the USA, I've picked out the key areas of interest that can effect the down stream pattern in Europe:

...WITH MUCH UNCERTAINTY ASSOCIATED WITH TRENDS TO AND AWAY FROM SYSTEM PROGRESSION. CURRENT WATER VAPOR IMAGERY UPSTREAM OVER THE PACIFIC SHOWS SOME AMPLIFIED SYSTEMS THAT CAN PROVE SLOW TO TRANSLATE..

My reading of this is that the impact of this upstream may not be properly modelled yet.

THERE IS SOME POTENTIAL FOR ERN US COASTAL SURFACE CYCLOGENESIS OF SOME MAGNITUDE EARLY NEXT WEEK WITH APPROACH OF AN AMPLIFIED LEAD MID-UPPER LEVEL TROUGH

This low that might develop in the southern stream of the jet is a complicating factor.

 THIS PATTERN WILL OFFER SUBSTANTIAL UNSETTLING HEIGHT FALLS ACROSS THE WRN US AND INTO THE CENTRAL US NEXT WEEK THAT LEAD TO AMPLE DOWNSTREAM ERN US HEIGHT RISES AHEAD OF SYSTEM APPROACH.

This is the more important aspect as we do need high pressure to develop there and edge east towards Greenland.

Of course with a more amplified upstream pattern we do need a bit of luck and for the pattern to get sufficiently east to have western Europe on the cold side of low pressure.

 

[knocker]

40 minutes ago, Ali1977 said:

Can't post pictures but the GFS control has a pretty good FI too....As things start shaping up at day 10 the ECM, and GEM need to get and stay on board.

knocker, as you are not a coldie like most of us - can you see things changing considerably this side of Xmas? Ian F if your watching, what do you think? White Xmas???

Xmas is a long way hence weather wise but I would have to say the percentage play at the moment would be little change. Mind if the GEFS developed this idea it might be a different ball game but it's not doing so at the moment.

 

[Altohumorous]

Those fairly FI charts showing northerlies etc appear to show the NAO too far west, we'd quite likely end up on the milder side of the troughing, at least some or most of the time, should that type of scenario come to pass. Certainly the signs of pattern change from 2/3 days ago are looking to be consistent so far, coming more into the reliable frame.

I've had a strong belief for mid-december change since about 2 weeks ago. Some serious rain-producing weather patterns being modelled consistently for this weekend into early  next week. Places looking most at risk are west and south Wales, SW and central England (central southern later), much of Ireland especially the south. Western coastal areas also under threat due to persistent high winds.

[Iceberg]

I've been trying to get this loaded up for a few days, to show that GEFS really are following the trend for a pattern change. The quality is not very good, as I am on my phone, but it shows the point anyway.

GEFS shows a very clear pattern change (850's shown) at around the T140-T180 mark, by the end of the run, A majority of the runs bring in the much colder 850's.

For me it's less will a pattern change occur, but rather how will it show itself, will the artic high migrate enough to Greenland, will enough PV be left to interrupt things. The pattern change to a blocked is pretty certain.

[MPG]

12 minutes ago, Iceberg said:

I've been trying to get this loaded up for a few days, to show that GEFS really are following the trend for a pattern change. The quality is not very good, as I am on my phone, but it shows the point anyway.

GEFS shows a very clear pattern change (850's shown) at around the T140-T180 mark, by the end of the run, A majority of the runs bring in the much colder 850's.

For me it's less will a pattern change occur, but rather how will it show itself, will the artic high migrate enough to Greenland, will enough PV be left to interrupt things. The pattern change to a blocked is pretty certain.

Thats a great tool, any link to that?

[Iceberg]

Its on the meteociel site under GEFS then tables(French), unfortunately its blocked at my work currently, so I can't show the link.

[Summer Sun]

11 minutes ago, MPG said:

Thats a great tool, any link to that?

 

9 minutes ago, Iceberg said:

Its on the meteociel site under GEFS then tables(French), unfortunately its blocked at my work currently, so I can't show the link.

Here is the link http://www.meteociel.fr/modeles/gefs_table.php?ext=1&x=306&y=141&ville=Londres

[Nouska]

25 minutes ago, MPG said:

Thats a great tool, any link to that?

Here's the link to the Europe wide view - just click map for location you want.

http://www.meteociel.com/modeles/gefs.php?carte=1&table=1

Use the ascendant or descendant function to get a better view of the trends.

T2m ascending ...  

There is another new function added to the ensembles - a probability view.

http://www.meteociel.com/modeles/gefs_cartes.php?ech=0&code=0&mode=2&proba=1

Edited December 4, 2015 by Nouska
additional link

[Pixel]

41 minutes ago, Iceberg said:

Its on the meteociel site under GEFS then tables(French), unfortunately its blocked at my work currently, so I can't show the link.

great find, like this sort of representation visually.. bookmarked - Public thanks to all those who posted links (-:

[Mucka]

I think what we are seeing is a strengthening signal for the jet to continue to want to dig south and increased amplification as we head toward mid month.

This will result in the weather staying largely unsettled but with increasing prospects for brief wintry outbreaks, especially for the north, as the lows dig further South and we get ridging behind.

So if correct we will slowly see less disturbed weather develop as we head toward last 3rd of the month.

 

It still appears that the models will want to develop a trough into NorthWest Europe into the second half of the month so there will be scope for slightly longer and colder outbreaks from the NE later.

We have competing forces for the last 3rd of the month, a strong jet but a more amplified pattern which will mean we will likely see various attempts at building a ridge in the Atlantic as lows move through but these will likely be overrun - at least through the 3rd week of December. However if the PV relents from spitting deep lows across the Atlantic even for a while blocking could take hold.

The point being that we will be in far better position for some blocking and more prolonged cold shots as we head toward the final 3rd of the month and this window of opportunity looks wide enough that we will get a few bites at the cherry (which may well be needed)

In summary, no signal for cold and blocked as yet but an increasing signal for more typical winter fare with cold shots and increasing potential.

ECM London ensembles 

 

 

Still slowly edging the right way in FI as the mild runs become fewer and the cooler runs gather.

 

PS

Is today the first day of the new GFS proper?

Edited December 4, 2015 by Mucka

[Polar Maritime]

GEFS yesterday Mucka.

[Mucka]

Right, thanks Polar.

 

UKMO looks to have some potential at 144 (amplification upstream) but quite different to GFS in that regard.

 

 

GFS 12z quite disappointing for coldies it has to be said but hopefully it is far too progressive and just a one off.

 

We will have a better idea after the ensembles and ECM are out.

Edited December 4, 2015 by Mucka

[gottolovethisweather]

3 hours ago, Iceberg said:

I've been trying to get this loaded up for a few days, to show that GEFS really are following the trend for a pattern change. The quality is not very good, as I am on my phone, but it shows the point anyway.

GEFS shows a very clear pattern change (850's shown) at around the T140-T180 mark, by the end of the run, A majority of the runs bring in the much colder 850's.

For me it's less will a pattern change occur, but rather how will it show itself, will the artic high migrate enough to Greenland, will enough PV be left to interrupt things. The pattern change to a blocked is pretty certain.

Agreed, I have been looking at GEFS ensembles spreads myself and have been solely concentrating on the 12zs to see if I can determine a trend using London as an example. For any others who wish to look at them, they are available on meteociel and I made reference to them here. 

post referring to GEFS spreads on meteociel

As to my forecasting attempts at that time, I proved way off but that's life.  These charts are still of use though, that is for sure. Thanks for reminding about them again, Iceberg.

 

EDIT: I obviously hadn't read the other posts when I posted this, so my apologies but same sentiments apply.

Edited December 4, 2015 by gottolovethisweather

[gottolovethisweather]

2 hours ago, Summer Sun said:

 

Here is the link http://www.meteociel.fr/modeles/gefs_table.php?ext=1&x=306&y=141&ville=Londres

Ha ha well done Summer Sun, also mentioned this in my post above.

Edited December 4, 2015 by gottolovethisweather

[Ali1977]

Disappointing GFS, to be expected I guess....Lets hope it was onto something and the ECM shows some promise.

[Iceberg]

Yep meto t144 is far more like the 06z gfs and similar to the ecm 00z. 

Gfs has a very different scenario at t120-140 off the eastern seaboard. 

For me the meto t144 is so far the chart of the day for potential. 

12z gfs still had periods of sleet and snow for the north. 

[ItNeverSnowsInWindsor]

Will be interesting to see where the GFS 12z sits in the GEFS ensembles. I suspect it would be a warm outlier in the latter timeframes in contrast to the 6z run.

[Mucka]

Just now, prolongedSnowLover said:

Will be interesting to see where the GFS 12z sits in the GEFS ensembles. I suspect it would be a warm outlier in the latter timeframes in contrast to the 6z run.

I was thinking about posting the very same thing, looks like a rogue run but the ensembles aren't coming out at the moment so no way to check.

[ItNeverSnowsInWindsor]

The GFS 12z looks like it's overdoing the low off the Eastern seaboard as early as 120hrs which goes on to effect the outcome later on. Lets see what ECM, GEM and JMA show this evening.

Edited December 4, 2015 by prolongedSnowLover

[winterof79]

6 hours ago, tight isobar said:

This morning s suite leaving a lot to ponder mid month onwards. ....

I think its almost nailed foe a mid month pattern change...perhaps in a more notable way than some suspect! !!

Some interesting output.

GFS having a Mr Benn moment "and then as If by magic" cold turned into warmth

Still thinkIng end of year for change to winter.

[bryan629]

3 minutes ago, Mucka said:

I was thinking about posting the very same thing, looks like a rogue run but the ensembles aren't coming out at the moment so no way to check.

Same here, the run ends with what looks like a fully formed PV... that goes against the grain of the strat forecast and wave activity... also what put me onto the scent of an outlier was if you look from say T+90 and scroll to around T+144.. is a low sat over iceland and doesnt budge at all during the time frames... absolutely no reason for it to just sit there like a pinned catherine wheel.. so as you say lets wait for the ENS