Model Output Discussion 01/09/17

[northwestsnow]

6 minutes ago, Dennis said:

anomalies by EC

Looks fabulous 

[Had Worse]

Nearly off the scale.

 

Edit, It is off the scale.

Edited November 19, 2017 by Had Worse

[knocker]

Worth a quick look at the GEFS, EPS and NOAA anomalies this evening not because they are useful, because they are decidedly not but merely to illustrate the difference. About the only thing they agree on is the vortex over Siberia and the lobe in NE North America and the Atlantic is still west of the UK.

Edited November 19, 2017 by knocker

[karlos1983]

25 minutes ago, Dennis said:

anomalies by EC

Lol we’ve been here before!! Last year if memory serves me right. 

I know it’s an anomaly chart, but if Carlsberg did Blocking highs........ 

Edited November 19, 2017 by karlos1983

[ANYWEATHER]

Hi Folks , the journey en route to cold remains perplexing , frustrating, and often infuriating , but the signal remains from the ops in the days ahead is for ahead to turn colder after a milder blip this week; How cold and how we get there remains up in the air as the gfs does show some stormy options , not without question...But late November could well see some very interesting synoptics  which has been very absent in the last few years....

[mpkio2]

On 10/11/2017 at 18:34, mpkio2 said:

Just wanted to add to @Steve Murr earlier post regarding "model volatility" in output - this always happens, as Steve points out, in these kind of complex, atmospheric changing situations; especially heading into a negative AO phase, the models finding it difficult in how ridging in the Atlantic, Arctic high will interact with the fledging Polar Vortex and how the outcome Polar Volticies will behave (re be positioned and affect mid-lats). It's quite a lot for a computer model to predict!

Also, I think its best we get to where the models start to form ridging or HLB and how fast or slow the low that comes of America around the 16th November - the models are struggling at this point, because they can't fathom how it wil affect the NWP, which is why we are seeing many different outcomes post this point!  Look above and see how this is illustrated above with how each model structures that low sitting to the west of the UK!!

Theme/trend is still there (Blocking in/around Arctic), which is good if you wan. So, expect different outcomes post Day 5 period and beyond - let's get to where the blocking starts to form, then we can worry where we will get the cold and snow from. 

 

 

On 11/11/2017 at 21:52, mpkio2 said:

But I'm still cautious until we get nearer to 17th Novememberand see what the models say then.

Still keeping the faith, chaps!

 

Hello all once again!!!

Well, it sure has been a roller-coaster of an experience looking at the model's struggle with the upcoming blocking in the Arctic, eh? Talk about causing some drama!!!!

I haven't been really active on here because, as I stated above in my earlier posts from a week ago, I expected the models to "flip-flop" around with the upcoming pattern and descending AO - it happens every time when a pattern like this wants to set up, with inter-runs saying "mild"  one run and "cold"  the next...or even, as we#ve seen over the past few days, the models lock onto a pattern, only to latch on to a new one a few runs later!

As I said above, I was cautious about the "amplified" colder runs, because of how the models struggle with these set-ups. And sure enough, the models were off from what they were predicting (Post Day 5 period onwards)(Though correct with blocking in Arctic around Greenland!):

12z GFS 10/11 T216:

12z ECM 10/11 T216:

And what actually transpired....

12z ECM 19/11 T0:

The models couldn't predict the west -NAO setting up instead the EAST -NAO that all of us coldies want, and thus, a new pattern has occurred to take place. It's these kinds of details and teleconnection and atmospheric changes that are currently taking place causing the models to struggle, with wild model violaty output all over the shot.

I'm encouraged by the recent 12z ECM and its evolution to a colder outlook for the UK...

12z ECM 19/11 T120:

Very nice!!!

But how much faith can we put into one run?

A new trend has to follow before I can believe anything that's going to show up in the coming days' runs.

So, I'm not believing anything post t96, because pattern change can easily take place during these unpredictable and unstable model times!

Always optimistic, but cautious too....

~mpkio2~

 

[stewfox]

GFS 18z.. first pub run of the winter that could be ticket only- lock in . 

[Allseasons-Si]

4 minutes ago, Dennis said:

anomalies by EC

Yes Dennis,was just going to post that but here is the mean geopotential height anomoly's from gefs and ecm,pretty good agreement there

also the mean preasure charts from same models and timeframe,also in some kind of agreement with the main lobe of pv over to the Siberian side and heights building into the Atlantic

latest 500mb outlook from NOAA shows some ridging in the Alantic too and main lobe of pv in the same location as the mean charts above,in fact,do i see a four wave pattern there?

NAO/AO teleconnections still show us going into neg territory then rising to neutral with scatter as to be expected with the uncertainty and volidity of the models

30/10 hpa strat temps shows a magnificent cooldown from the average(grey line) getting down to nearly -80,then a little tick up,it would be nice to get a warming to punch those cold temps down to the mid latitudes

and finaly,will we see some nacreous clouds,could do in north of Scotland with the cold temps of the pv edging closer

good model watching again today but we have all been here before though not long ago,i just hope it comes off this time,WE DESEVRE IT

 

[stratty]

14 minutes ago, mpkio2 said:

 

Hello all once again!!!

Well, it sure has been a roller-coaster of an experience looking at the model's struggle with the upcoming blocking in the Arctic, eh? Talk about causing some drama!!!!

I haven't been really active on here because, as I stated above in my earlier posts from a week ago, I expected the models to "flip-flop" around with the upcoming pattern and descending AO - it happens every time when a pattern like this wants to set up, with inter-runs saying "mild"  one run and "cold"  the next...or even, as we#ve seen over the past few days, the models lock onto a pattern, only to latch on to a new one a few runs later!

As I said above, I was cautious about the "amplified" colder runs, because of how the models struggle with these set-ups. And sure enough, the models were off from what they were predicting (Post Day 5 period onwards)(Though correct with blocking in Arctic around Greenland!):

12z GFS 10/11 T216:

12z ECM 10/11 T216:

And what actually transpired....

12z ECM 19/11 T0:

The models couldn't predict the west -NAO setting up instead the EAST -NAO that all of us coldies want, and thus, a new pattern has occurred to take place. It's these kinds of details and teleconnection and atmospheric changes that are currently taking place causing the models to struggle, with wild model violaty output all over the shot.

I'm encouraged by the recent 12z ECM and its evolution to a colder outlook for the UK...

12z ECM 19/11 T120:

Very nice!!!

But how much faith can we put into one run?

A new trend has to follow before I can believe anything that's going to show up in the coming days' runs.

So, I'm not believing anything post t96, because pattern change can easily take place during these unpredictable and unstable model times!

Always optimistic, but cautious too....

~mpkio2~

 

lol 100% accuracy by ECM on that account  

[mpkio2]

2 minutes ago, stratty said:

lol 100% accuracy by ECM on that account  

I can't edit my post for some reason, but I posted the wrong image for the 12z 10/11 ECM run.

This is what it was predicting on that day:

12z ECM 10/11 t216:

[Allseasons-Si]

ECM shows some cool/cold uppers flooding down from the NW from 120 hrs to 168 hrs even as far south as SE england and not at the silly o'clock timeframe either,brrrr!!!

 

Edited November 19, 2017 by Allseasons-si

[stratty]

1 minute ago, mpkio2 said:

I can't edit my post for some reason, but I posted the wrong image for the 12z 10/11 ECM run.

This is what it was predicting on that day:

12z ECM 10/11 t216:

...........am hoping it is 90% accurate tonight, with a 10% upgrade ! 

[Methuselah]

4 minutes ago, stratty said:

...........am hoping it is 90% accurate tonight, with a 10% upgrade ! 

But, alas; I fear it'll be 10% accurate, with a 90% upgrade...

[Allseasons-Si]

6 minutes ago, Ed Stone said:

But, alas; I fear it'll be 10% accurate, with a 90% upgrade...

If we see a 1% upgrade from the 18z ,it will be a bonus,but it will take some beating to beat the ecm tonight,baby steps

and toys on puppet strings

Edited November 19, 2017 by Allseasons-si

[Ice Day]

Big differences between ECM and GFS at just 96hrs!!!

ECM

GFS

 

[bobbydog]

at 120hrs, some of the colours and squiggly lines are slightly different to the previous run

[Allseasons-Si]

4 minutes ago, Ice Day said:

Big differences between ECM and GFS at just 96hrs!!!

ECM

GFS

 

Good spot there Ice day,the gfs still looks -NAO west based but has a better separation from troughs/lows with better heights into Greenland,just cannot make it up can you

as always,...pin the tail on the donkey and it will run for that dangling carrot

[Eskimo]

Different orientation on the low compared to the 12z means more cold on its northern flank...meaning maybe a few wet flakes for high ground in the north. If that low can, somehow, be squeezed further south, could mean more fun and games perhaps. 

Perhaps, could, maybe. 

[Ice Day]

5 minutes ago, Allseasons-si said:

Good spot there Ice day,the gfs still looks -NAO west based but has a better separation from troughs/lows with better heights into Greenland,just cannot make it up can you

as always,...pin the tail on the donkey and it will run for that dangling carrot

Absolutely, but at least we can be 100% confident that the ECM has nailed it........can't we.......anyone!

Edit. And this is the difference at 6 days out:

ECM

GFS

Someone's got their sums very wrong!

Edited November 19, 2017 by Ice Day

[Allseasons-Si]

I am watching that back door cos heIghts have been gaining momentum the last few runs,now the 18z is an example of this,heights are gaining strengh eastern Greenland extending east while Siberian heights gaining too,one to watch,this will force the trough further SE.

Edited November 19, 2017 by Allseasons-si

[Cheshire Freeze]

18z GFS daring us to get the BBQ out rather than the scarfs and ear muffs

[Allseasons-Si]

4 minutes ago, CreweCold said:

18z GFS daring us to get the BBQ out rather than the scarfs and ear muffs

Short term pain for long time gain,maybe?

...but,it is 174 hrs out!

Edited November 19, 2017 by Allseasons-si

[Ice Day]

3 minutes ago, CreweCold said:

18z GFS daring us to get the BBQ out rather than the scarfs and ear muffs

Indeed so.  Given the wild divergence in the models today (again), perhaps there's something brewing that they are struggling to get a handle on? I would always tend to go with the ECM but it didn't perform so well last winter so who knows?

[Cheshire Freeze]

Just now, Allseasons-si said:

Short term pain for long time gain,maybe?

I'm very doubtful-

All very familiar to me, it has been the same way for the past few years. We see Euro heights repeat ad nauseam. The ECM has often over amplified things and I suspect we'll see a backtrack from it on the 0z run. 

[bobbydog]