Model Output Discussion - 18z 31/10/15 onwards

[knocker]

I think that is right Blue and on top of that the signal itself is quite muted at the moment, it will take a couple of days before any mean anomaly begins to appear even if GFS is onto something.

 

That's not quite correct as it shows up quite markedly on the GEFS post T264 and the five day mean. But at this stage it's pretty much on it's own even if eventually it does turn out to be correct.

[Mucka]

That's not quite correct as it shows up quite markedly on the GEFS post T264 and the five day mean. But at this stage it's pretty much on it's own even if eventually it does turn out to be correct.

 

Thanks Knocker. As stated GFS has been showing it but other charts such as the ones you posted from NOAA which were the ones I'm referring to do not.

If GFS is onto something I expect it show on those and ECM over the next couple of days, if not I would be very sceptical of GFS output.

Edited November 4, 2015 by Mucka

[Cheshire Freeze]

Regardless of local synoptics, the most striking thing to me is the struggle to form any meaningful vortex on recent runs....mid November on the following chart in a strong el Nino year and it looks like it's taken a few blows already. It may be tropospherically led but it's striking nonetheless

 

Edited November 4, 2015 by CreweCold

[Ali1977]

Another Northerly blast incoming...trends still there!! Although not quite as good as the last.

Edited November 4, 2015 by Ali1977

[Cheshire Freeze]

Deep into FI and the vortex is shredded, virtually none existant

 

[Ali1977]

Deep into FI and the vortex is shredded, virtually none existant

 

Bizarre in a strong El Niño and in November - still nothing from the professionals mentioning possible cold spell - GFS goose chase or METO egg on face...I say goose, METO are normally correct!!

[Cloud 10]

Very interesting 18z and delivers the first "black hole" anomaly of the season.

 

[tight isobar]

Gfs continues' like a dog with a bone .

And the northern hemespheric prophile

further suggesting,

Old mother Hubbard 's

gone shopping .....and the cupboards are filling !.

[Cheshire Freeze]

Bizarre in a strong El Niño and in November - still nothing from the professionals mentioning possible cold spell - GFS goose chase or METO egg on face...I say goose, METO are normally correct!!

 

Out at 384 hrs but this is one of the most bizarre charts I've ever seen in all my years of model watching. Pretty much universally higher than average pressure across the N latitudes and perhaps one of he weakest mid-late November Vortex scenarios I've ever seen

 

[mountain shadow]

Very interesting 18z and delivers the first "black hole" anomaly of the season.

 

gfsnh-12-360.png

Crikey. Last time I saw that was in 09/10.

Meto going for a mild/average November with no hint of a cold spell from them.

Feet firmly on the ground.

[Ravelin]

Another Northerly blast incoming...trends still there!! Although not quite as good as the last.

Not sure I'd quite agree with that. 18z doesn't maybe have as strong looking a northerly but the trough seems to get much further south. By the end of the run most of Europe is under -ve 850s.

It'll be a minor miracle if it comes to reality anyway and even if it does its unlikely to look exactly like any of the permutations we've seen so far.

If we see something similar start appearing on the other models, and it gets closer day by day, then I might start to get more than just curious.

Edited November 4, 2015 by Ravelin

[Nick F]

Deep into FI and the vortex is shredded, virtually none existant

 

 

I can see plenty of 500mb vortices in that chart meandering around high latitudes, question is, will they position favourably to bring cold to our shores later this month? 2 consecutive cold northerlies in a row from GFS FI but I still wouldn't like to put a wager on it for a while yet until we see whether that ridge develops over NE Canada and far NW Atlantic/Labrador - this appears to be linked to the PFJ diving south over North America allowing pressure heights to build over eastern Canada.

[london and south east kent]

Hi still looking good for cold mid November onwards trending in the right Direction will the ecm start to see this in next few days .

[East_England_Stormchaser91]

Very interesting run indeed. Trend has if anything improved. The replacement of the nagging heights over Aleutians and Alaska to raging low pressures seems to cause the GFS to develop a kink in the jet in our favour with raising the heights over E Canada and Labrador and then onto Greenland. That in turn flooding the cold air out of Greenland to the eastern side of it and plunge the UK and Scandi into proper winter weather.

It's all about anticipation and the action taking place on the N American continent that has a big effect further down the line.

If we do see this happen, and with the already snow covered Eurasian land mass, It could shape up to be an interesting winter season ahead!

A pinch of salt taken for now though. I won't hold my breath.

Edited November 4, 2015 by East_England_Stormchaser91

[Cheshire Freeze]

Greenland high of the day award goes to.....perturbation 10!

 

[Allseasons-Si]

Greenland high of the day award goes to.....perturbation 10!

 

gensnh-10-1-336.png

 

 

And there are a few others to back it up too

 

i do like P7 though with a stronger ridge in the Atlantic

 

18z 336hrs

 

 

and P10 @ 384hrs

 

 

all for fun though

[nick sussex]

This thread has moved on quickly this evening so without looking at the GFS 18hrs run I suspected it was still going for the northerly!

 

I think expectations maybe getting a bit too far ahead of the synoptics, the Euro limpet high is still there at T240hrs and it takes several days after that for the cold to head south.

 

The issue is whether any negative NAO sets up too far west and whether we'll see the low fill over the UK. Its of course nice to see the outputs showing up some more interesting solutions but theres a long way to go.

[bobbydog]

FI or not, you won't see many charts like this in november-

yet they keep appearing....

[knocker]

The 18z GEFS (P) anomaly has ridging Canada and to the SE of the UK with the trough to the NW giving once again the NW split. By T360 it has moved the ridge a tad east and removed the ridging to the SE and has a weak trough in the eastern Atlantic. This would serve to bring more unsettled weather to perhaps the whole of the UK at times with variable temps but mainly around average.

 

This morning's ops run epitomises the N/S split  scenario except towards the end when it builds HP over the UK once again as can be seen on a snapshot chart.. But given the mobility of the system reading too much into one run is mugs game so essentially at the moment it's still looking like the familiar scenario of a north south split becoming perhaps more unsettled in the ext period with temps varying around the norm. Oh and the Rjindvelts Early Sensation seem to be doing fine at the moment.

Charts weatherbell and http://www.tropicaltidbits.com/

Edited November 5, 2015 by knocker

[IDO]

A trend in the FI of the GEFS strat has been a clear strengthening of the polar vortex and an indication it may become a powerful driver for the medium term assuming coupling with the trop is maintained:

 

D16 and it is clearly developing:   Temp cooling: 

 

Looking at the GEFS at D16 and there is an indication the trop PV is beginning to become organised. The mean and control: 

 

 

 

In theory if there is coupling then the four wave MLB's should sink bringing in the zonal energy. Early days but that would hint at a mildish late November into December with wind and rain becoming more topical. As these blocks get jostled from the pattern change around mid month heights may give a brief northerly flow, but it is just as likely we could be under the ridge rather than the trough.

 

At least 3-5 days to see if this pattern will develop or is a false signal, but it seems rather plausible especially at this time of year. So N/S split in the interim before we head towards normal service, and the latest CFS week 3-4 anomalies are very strongly favouring that:

 

[bluearmy]

will the n Asian developing block hold. Will the n American ridging develop around day 8/9 ? And if it does, will it simply be a transient bump in the jet stream heading west to east or could it devlop into a more solid mid Atlantic feature? No promises on anything but a combination of the two could lead to a general n European trough. My money would still be on a west based -NAO if we did get n Atlantic ridging. Whatever happens, it's very early still and no one should expect much of a wintry flavour. Building blocks and repeating patterns.

[solarcycle]

Can someone please explain how one post on this page says the vortex is shredded yet another, presumably using the same nwp output says it is forming strongly. Coming to completely opposite conclusions makes no sense to me. Who is it who has this wrong? It has to be one or the other.

[Frosty.]

The Gfs 00z op run in low res again produces wonderful wintry charts for coldies on here to enjoy..another very encouraging run if, like me you are fed up with constant very mild weather!  

[knocker]

Can someone please explain how one post on this page says the vortex is shredded yet another, presumably using the same nwp output says it is forming strongly. Coming to completely opposite conclusions makes no sense to me. Who is it who has this wrong? It has to be one or the other.

 

Well I'm certainly no expert nor am I commenting on previous posts but it does appear to be starting off quite strong.

[knocker]

This morning's ecm run epitomises the N/S split as the two snapshot charts shows.