Model Output Discussion 18th Nov.2013-12z onwards.

[Yarmy]

seems gfs is that confused its thrown towl in at 192 hrs   

 

Yes Low Rez not appearing. Fed up of all the abuse on NW, no doubt.

 

Anyway a better run than the 0z, but since it looks nothing like it you can hardly have any confidence. 

 

0z

 

 

 

6z

 

[Cecil Hogmanay Melchett]

GFS06Z brings ina countrywide blizzard,we can dream fellow net weather coldies....we can dream!  

[radiohead]

06Z GFS deep in FI showing what would be a significant rain/snow event .

 

 

Intense precip

[Barry12]

Much better GFS, the cold spell is extended on the 6z!!

 

 

Still got -4 uppers, with -6 uppers for the west at the end of the run, the cold never really leaves

[Cecil Hogmanay Melchett]

Much better GFS, the cold spell is extended on the 6z!!

 

 

Still got -4 uppers, with -6 uppers for the west at the end of the run, the cold never really leaves

GFS06Z is SENSATIONAL Barry.

If it happens like that we'll ALL be happy(well ok most of us).

[SMU]

GFS throws another solution out there.... For anyone looking at the UK under the 'europe' microscope should withdraw to the Northern Hemisphere plots to look upstream at developments.

 

Its going to be a rollercoaster of ups & downs that's for sure-

 

I think what I will do at the end of this for the ACTUAL chart of 6 DEC 12z I will compile an image of all the model runs for that day & score them to see what was the best run of them -

 

If anyone wants that then let me know- If we started from the 27th of Nov with 6 days of runs from 216 down to 72 we will get plenty of coverage.

 

S

Edited November 29, 2013 by Steve Murr

[nick sussex]

So this game of model musical chairs continues! The GFS 06hrs run brings a northerly then a shortwave snow event and then a nice looking deep low heading east across the USA and Canada which with a bit more amplification could carve an even stronger ridge ahead of it, still a small chance of an east/ne flow as the ridge topples.

 

However how much confidence can you have in the outputs with these continued wild swings and their inability to decide what happens upstream, nice to see the GFS 06hrs at least bring some interest but I think we're going to have to wait till the timeframe gets closer before the jury delivers its northerly verdict!

[Yarmy]

GFS06Z is SENSATIONAL Barry.

If it happens like that we'll ALL be happy(well ok most of us).

 

And all achieved without Greenland, Iceland, or Scandi heights. Of course, it's nothing like the 0z so it can't be taken seriously. Somehow every run seems to deliver polar air from the North, but each time taking a different route.

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

looks  like the  cold spell here to at least DEC  15   the  express  might  be  right  for a  change!!

[garbagebags]

I don't buy the 06z. I wish I did but I don't. I mean that low at +114 shooting across the Atlantic, where has that suddenly come from?? I bet that has dissapeared in the 12z. 

[Skyraker]

Ensemble Watch.

 

[Ali1977]

Let's see where the latest GFS sits within the Ens....Lately it never seems to sit anywhere near the middle after week or so...

[Tamara]

The GFS has an interesting scenario on its breakfast show output where after the initial arctic shot, something of a cut-off low tracks along the PFJ from the atlantic and deepens rapidly as it is ejected south eastwards with some of the residing dense cold polar air mixed into it on its northern flank. Just taking the GFS at face value for a moment and assuming it verified - this type of evolution could provide a snow event for areas to the north and east of the low pressure. A secondary amplification of the pattern upstream seems to facilitate this and delays the High toppling.

 

A shortlived arctic incursion, much as suggested all along, remains the favourite with mid latitude high pressure returning immediately afterwards - but there is a small chance of an evolution like the GFS suggests here giving a second bite at the apple with enough support from lower heights over Europe from the initial northerly perhaps underpinning the toppling High for a while longer before it returns to sit close to the UK.

 

Essentially same eventual outcome - but perhaps a bonus surprise to extend the cold snap

Edited November 29, 2013 by Tamara תָּמָר

[tight isobar]

6z gfs throws everything bar the kitchen sink in. And develops somewhat incur mystery LPS.a run to a degree that can be dismissed!!!

[bryan629]

gfs @ day 8 cfs a day earlier 

 

 

 

very similar... although not identical...

 

 

 

 

[Snowman.]

 

Ridge building north. 

[phil nw.]

Crikey we will all be worn out before Winter starts as the 06Z GFS run joins the party.

So many slight variations to the projected northerly modeled for the end of next week by different runs.

That run shows that even with a modest amount of amplification we can get some of that deep cold south from that Scandinavian trough digging well south.

The NAEFs and ECM 850 anomals. still support this cold spell-day 8

 

http://176.31.229.228/modeles/gens/naefs/run/naefsnh-0-1-192.png?12

http://www.meteociel.fr/modeles/ecmwf/runs/2013112900/EDH100-192.GIF?29-12

 

uppers around -4 to -6C.

 

It's still a case of watching and waiting for a few days to see how cold with op.runs still deciding the details.

[Cecil Hogmanay Melchett]

Well after a bit of shamless ramping its pretty obvious its all about the secondary low,the slower that moves off the Eastern seaboard the better.

[CasMan]

Ensemble Watch.

 

Where is the best place to find the ensembles ?, and how long after the actual run do they appear ? i may be doing something wrong but the ensembles on Netweather doesnt tell you which run they are from

 

Edit: 

 

The graph section shows the run, but the map section doesnt, but i assume it is the same run

Edited November 29, 2013 by CasMan

[Troubleatmill]

Where is the best place to find the ensembles ?, and how long after the actual run do they appear ? i may be doing something wrong but the ensembles on Netweather doesnt tell you which run they are from

 

Edit: 

 

The graph section shows the run, but the map section doesnt, but i assume it is the same run

 

It does, look where it says 00z, personally i still prefer the Wetter ones:

 

http://www.wetterzentrale.de/topkarten/fsenseur.html click on 500hPa Geopot. - Alle Member

 

http://www.wetterzentrale.de/topkarten/fsavnmgeur.html click on GFS 1° + GFS Ens Europa then use the drop downs

 

But each to their own

Edited November 29, 2013 by tempestas

[Weathizard]

500 mean

http://176.31.229.228/modeles/gens/run/gens-21-1-204.png

850 mean

http://176.31.229.228/modeles/gens/run/gens-21-1-204.png

Not quite sure what to make of the mean, there's quite a few zonal runs in the ensembles though, Op definitely on the cold side at that stage. (Edit: By zonal, not default zonal ie SWlies but chilly -2/4 uppers zonal)

Edited November 29, 2013 by Weathizard

[Tom Montalbano]

I see the 06z GFS has lifted the spirit of us cold weather fans again, with yet another scenario post t200 (too far out to give it much credence yet). High pressure relaxes back out into the Atlantic and with enough NW/SE tilt on the jet, and heights remaining low over Europe, we get a low tracking SE across the UK.

As Tamara suggests above, there would be enough embedded cold air left, after our brief northerly flirtation to suggest a snow event ,on the northern flank of this low, for Northern parts of Britain.

Not too long to wait before we see what the 12z runs make of this development but of course it could all be gone in the blink of an eyelid and of course at that range, not worth getting our hopes up just yet.

Tom.

Edited November 29, 2013 by Kentish CZ

[radiohead]

The low at T180 is even more intense on the control run.

 

[SomeLikeItHot]

ECM London 0Z Ensembles are interesting. While the Op is below the mean its pretty much in the middle of the main cluster from day 8 comprising probably 2/3 to 3/4 of the ensemble members, with the mean pulled higher by a minority of very much higher runs.

 

 

So looking good for something cold, at least for a bit, although still with a risk of a very different and much warmer outcome.

 

(That path with the min of -10 and day time of below -5 on the 11th is interesting!).

Edited November 29, 2013 by SomeLikeItHot

[Troubleatmill]

I see the 06z GFS has lifted the spirit of us cold weather fans again, with yet another scenario post t200 (too far out to give it much credence yet). High pressure relaxes back out into the Atlantic and with enough NW/SE tilt on the jet, and heights remaining low over Europe, we get a low tracking SE across the UK.

As Tamara suggests above, there would be enough embedded cold air left, after our brief northerly flirtation to suggest a snow event ,on the northern flank of this low, for Northern parts of Britain.

Not too long to wait before we see what the 12z runs make of this development but of course it could all be gone in a blink of an eyelid and of course at that range, not worth getting our hopes up just yet.

 

Tom. 

 

Yes the GFS 06z has a snow event midlands northward around the 228 hours, disruption a definate if that came off