Model output discussion - into the start of Winter

[feb1991blizzard]

2 minutes ago, nick sussex said:

The GFS in a complete u turn with the block blown away and onto an attempt to bring in a northerly .

The UKMO only goes to day 6 but that looks a bit more like earlier outputs with the shortwave cutting back sw so might end up looking markedly different and more inline with the blocking scenario .

What we don’t want is a middle ground solution. So either full on block or full on northerly .

It will end up a tame N'ly with an East based plunge, said it all along. Thats showing now on the run at 200+.

[northwestsnow]

GFS still intent on shifting the PV away from Greenland into December.

Thats a good place for us coldies to be if it happens...

Edited November 25, 2020 by northwestsnow

[swfc]

6 minutes ago, nick sussex said:

The GFS in a complete u turn with the block blown away and onto an attempt to bring in a northerly .

The UKMO only goes to day 6 but that looks a bit more like earlier outputs with the shortwave cutting back sw so might end up looking markedly different and more inline with the blocking scenario .

What we don’t want is a middle ground solution. So either full on block or full on northerly .

Mlb nick on this run. That said some cold 850s going into Europe. So yes not bad imo

[Kentish Snowman in Yorks]

6 minutes ago, nick sussex said:

The GFS in a complete u turn with the block blown away and onto an attempt to bring in a northerly .

The UKMO only goes to day 6 but that looks a bit more like earlier outputs with the shortwave cutting back sw so might end up looking markedly different and more inline with the blocking scenario .

What we don’t want is a middle ground solution. So either full on block or full on northerly .

You just know that a middle ground solution is what we will end up with.  Murphy's law and all that!

What can go wrong does go wrong when it comes to UK cold!  That said it makes for fascinating viewing and I am interested to see what tonight's ECM makes of it all....

[swfc]

Just now, northwestsnow said:

GFS still intent on shifting the PV away from Greenland into December.

Thats a good place for us coldies if it happens...

Yep I'd bank that 12z gfs 

[Met4Cast]

1 minute ago, northwestsnow said:

GFS still intent on shifting the PV away from Greenland into December.

Thats a good place for us coldies to be if it happens...

Agreed. I think we can throw this GFS run in the bin, not because it doesn't show what we want but because of how much of a mess it is. There's high pressure and low pressure systems entangled up all over the place. 

[seabreeze86]

At least the GFS sorts out the no cold to tap into problem

[Daniel*]

GFS FI fits with extended EPS very well if you ask me. But never mind that range I’m noticing minor changes within T90 with continental drift and blocking.

[johnholmes]

28 minutes ago, Met4Cast said:

Agreed. I think we can throw this GFS run in the bin, not because it doesn't show what we want but because of how much of a mess it is. There's high pressure and low pressure systems entangled up all over the place. 

I'd be interested in your explanation of the last sentence, it strikes me as a bit sweeping having looked at the output, please?

[Nick F]

Looked like it was an epic 12z GFS shaping up as it was rolling out ... but we miss the deep cold thrust going into Scandi to east.

However, an injection of deep cold direct from the arctic into E/NE Europe and NW Russia not a bad thing IMO, should pressure build back to the NE to bring an easterly again, it would source this pool of deeper cold dropping down from the TPV and obviously increase the chance for a BFTE. However, pull the lobe of the TPV a little further west by 500 miles as it drops south, then we could see a bitter northerly.

Should we have to sit it out with high pressure in control, yes we still may have the inversion shallow cold, but for snow potential other than flurries, we need to hope MLB may position favourably eventually to let in deep cold at some point. But there is a risk of waiting and waiting while a less favourable change in upper flow pattern comes along, perhaps as the TPV returns towards Greenland, with sinking HLB as low pressure fills over southern Europe, allowing back in the Atlantic.

Edited November 25, 2020 by Nick F

[SMU]

Dont worry about the GFS op> I have followed it very close over the last 6-7 days & it was woeful every day not developing the first scandi high.

 

Look at this.

This is the GFS 12z for T72 today with the scandi High & a defined Easterly flow

Rewind 3 days to the 144 chart for the same timestamp > No Scandi High just a thin strip of Moderate pressure & a nothingness flow

The same with rewind 4 days to 168 no scandi high etc etc

To be fair no model has been particularly good through this but the 12z GFS has had a very strong zonal bias all the way through....

[Tim Bland]

13 minutes ago, seabreeze86 said:

At least the GFS sorts out the no cold to tap into problem

Will be like finding hens teeth to get an easterly with it sitting there taunting us! 

[bluearmy]

9 minutes ago, Daniel* said:

GFS FI fits with extended EPS very well if you ask me. But never mind that range I’m noticing minor changes within T90 with continental drift and blocking.

does it ?  in any case an slp mean for day 13 is also pretty academic imo …. 

having checked the eps mean for T312, the gfs isn't close - as others have said, that run is too left field to take much notice of 

[Met4Cast]

3 minutes ago, johnholmes said:

I'd be interested in your explanation of the last sentence, it strikes me as a bit sweeping having looked at the output, please?

Sweeping how? Here's an example.

It's an absolute mess of systems. High pressure sat across Europe barely moving, high pressure in the Atlantic just sat there barely moving with lows dotted all over the place too for good measure. It's messy and in my opinion, almost un-realistic in terms of a pattern that's likely to actually verify.

[Weather vane]

Now, that is a BLOCK to behold on Icon at 180hr. No cold build to our east unfotunately..

[sheikhy]

Cmon ecm give us a big one tonight!!!looks like gfs might have done one like the ukmo recently!!!still looking frosty and cold on both the ukmo and gfs so it could have been worse

[Weather vane]

24 minutes ago, seabreeze86 said:

At least the GFS sorts out the no cold to tap into problem

Daffodils by late Dec if these GFS charts verify (little chance prob).

 

[tight isobar]

12 gfs goes into classic pull the trigger.. then run mode!! But synopticaly.. its opening large doorways via blocking formats.. and knife edge cold spillage into our territory!!.. early /mid December shaping nicely.. i rekon the ensemble plots will be telling this evening..@mean line and drop support...

Edited November 25, 2020 by tight isobar

[ianmm94]

2 minutes ago, Weather vane said:

Daffodils by late Dec if these GFS charts verify (little chance prob).

 

A large high pressure with light winds circling from the north west, it would be cold under that so I doubt it

[Weather vane]

Just now, ianmm94 said:

A large high pressure with light winds circling from the north west, it would be cold under that so I doubt it

You're right, though still a horror show for the snow coldies...

[I remember Atlantic 252]

2 minutes ago, ianmm94 said:

A large high pressure with light winds circling from the north west, it would be cold under that so I doubt it

Aye, not that mild, average I'd say wet chart for here as well, Cheshire streamer

[Daniel*]

18 minutes ago, Steve Murr said:

Dont worry about the GFS op> I have followed it very close over the last 6-7 days & it was woeful every day not developing the first scandi high.

 

Yep the ECM has been light years ahead. All the talk at time about ECM being over amplified! 

GFS 12Z, day 8 forecast.... 6 days ago for this Friday, very zonal no evidence of blocking to NE.

       

 

ECM 12Z day 8 forecast, 6 days ago for this Friday we have a ridge! 

 

The soon reality , the ECM model not been having a great year to me but it has seemingly done very well with picking up the blocking to NE. Very good job, it only wavered once on blocking on a 00z run.

 

 

[Anthony Burden]

The only thing to say regarding GFS 12z confused . com

[Daniel*]

23 minutes ago, bluearmy said:

does it ?  in any case an slp mean for day 13 is also pretty academic imo …. 

having checked the eps mean for T312, the gfs isn't close - as others have said, that run is too left field to take much notice of 

Okay perhaps an exaggeration EPS is more flat, but there’s clearly likewise a westerly dynamic to what they’re showing. 

[johnholmes]

42 minutes ago, Met4Cast said:

Sweeping how? Here's an example.

It's an absolute mess of systems. High pressure sat across Europe barely moving, high pressure in the Atlantic just sat there barely moving with lows dotted all over the place too for good measure. It's messy and in my opinion, almost un-realistic in terms of a pattern that's likely to actually verify.

Thanks for replying, it does look a bit messy I grant you, best to try and pick the main features out I think?