Model Output Discussion - 05/01/2016 18z onwards

[karlos1983]

2 minutes ago, nick sussex said:

In terms of the GFS 18hrs pattern in the ne USA and Canada, this looks a no go in terms of what the PV is supposed to do. That's expected to remain over Hudson Bay. And the associated troughing expected to remain amplified.

The earlier shortwave though near Iceland is something that we need to watch.

I'm actually regretting watching the GFS 18z now 

Bambi just fell through the ice on that run 

Edited January 6, 2016 by karlos1983

[feb1991blizzard]

1 minute ago, *Sub*Zero* said:

You may be right about this run! 

I was wrong with my initial thoughts though!!, I always prefer the High too far West / too far North to begin with as corrections tend to be the other way but this time I should have been careful not to celebrate too early, you cannot have the 2 areas of low heights / troughing engaging each other that far North of the BI and get away with it, its game over once it happens.

[Kentish Snowman in Yorks]

That 216 chart on the 18z GFS would give an ice day quite widely would it not?  Especially in areas where there is already snow cover?

Hardly a disaster for coldies surely?!

[terrier]

So is the gfs picking up a new signal. Not so sure but guess we will see which way the models go Tommorow. Even if the latest gfs is seeing things differently we still look at a 5 day cold spell which ain't bad at all. 

[johnholmes]

12 minutes ago, swilliam said:

That was based on the 12Z

true and the 00z and the 12z yesterday and the 00z, in fact using the anomaly charts back 3 days for consistency.

 

[Nick F]

2 minutes ago, winterof79 said:

Quite correct do not fall into the trap of over analysing every GFS run.You will end up on Prozac.

Indeed, some frown on using the 500mb means/anomaly, but when they continually back a pattern, like the current trend for ridge north over Greenland and deep Euro trough, it has some merit by giving the likely broad scale trend for sustained cold and takes out the run to run wobbles.

With regards to the GFS, it is probably pushing too much cold east over eastern N America than would be expected with the current signal for more amplitude and slowing of the wave pattern as MJO moves through 7 and 8 ... so could be the case that 18z GFS is being too progressive in pushing out/ developing low pressure over the NW Atlantic and Sern Greenland.

 

[Chris K]

The smallest of changes can mean a totally different outcome down the line for our small part of the world. We are still looking at cold weather setting in and let's be honest, a lot of us were worried we wouldn't see a frost this winter...

Looking at the state of the vortex and the N Hemisphere patterns as a whole, the 18z run is still excellent in my opinion and at least could mean some snowy opportunities further down the line. No limpet lobe of vortex stuck over Greenland and FI will always shift around substantially with these sort of setups.

Let's see what the morning  runs bring

 

[snowice]

2 minutes ago, feb1991blizzard said:

I was wrong with my initial thoughts though!!, I always prefer the High too far West / too far North to begin with as corrections tend to be the other way but this time I should have been careful not to celebrate too early, you cannot have the 2 areas of low heights / troughing engaging each other that far North of the BI and get away with it, its game over once it happens.

This is at 240hrs yesterday's couldn't get 144hrs in agreement with ECM Ukmo I wouldn't loose any sleep over it we are heading in the right direction cold.

[tight isobar]

Can we just remember the 18zgfs has failed to follow tge 12zecm run on two occasions. 

With scuppering of the Atlantic ridging!!!!.

No panic here.

[Essex snowman]

Reading the last few posts on here would think it's a return to wind and rain well heads up everyone it's going to get cold so let's see how it goes night all 

[nick sussex]

8 minutes ago, karlos1983 said:

I'm actually regretting watching the GFS 18z now 

Well there has to be some drama! lol I'd disregard the GFS 18hrs run for the ne USA and Canada, the earlier shortwave though near Iceland is one of those things that might appear but because the pattern upstream isn't helpful to develop more WAA then it takes an age to edge the pattern further se.

The GFS flattens out the upstream troughing and flies against this from NCEP:

LATEST GUIDANCE MAINTAINS THE STATUS QUO WITH RESPECT TO THE EXPECTED MEAN PATTERN THROUGH THE PERIOD. A BROAD UPR LOW OVER E-CNTRL CANADA WILL ANCHOR AN AMPLIFIED TROUGH THAT EXTENDS INTO THE LOWER 48 WHILE ANOTHER TROUGH PERSISTS OVER THE E-CNTRL PACIFIC. BUNDLES OF ENERGY EJECTING FROM THIS LATTER TROUGH WILL HEAD INTO/PASS THROUGH A MEAN RIDGE NEAR THE WEST COAST.

 

 

Edited January 6, 2016 by nick sussex

[Methuselah]

Indeed Nick - over-analyzing isobaric kinks is okay of itself, but the broader picture is also important...And, anyhoo, forecasting the onset of cold weather is a lot easier than predicting its demise?

[JOPRO]

This run does show a warm up for the uk,but it is way out at 252hrs, as we all know how often do the models   verify at that range??

[swilliam]

9 minutes ago, karlos1983 said:

I'm actually regretting watching the GFS 18z now 

Bambi just fell through the ice on that run 

Yes - I am regretting making a comment on the difference the run was showing at an early time frame - I will not bother in the future.

Edited January 6, 2016 by swilliam

[chionomaniac]

Lol Good old GFS. Replacing a 1050mb Atlantic high with a deep trough by the next run at day 10. Methinks stick to the ensembles!

[phil nw.]

Relax guys tonights day 5 fax

 

It's on track.The broad pattern for next week is for cold.

Edited January 6, 2016 by phil nw.

[Allseasons-Si]

It's one run,and i will believe it will be a mild outlier

if it shows on the 00z run,then i will have my doubts,but i will think it won't

night guys.

[bradymk]

Last night 18z gave us this 

Today's 00z gave us this 

Tonight 18z gives us this

And for those that are maybe new and worried, don't worry, the 00z will probably look completely different again.

We have good agreement now from GEFS and EPS of a sustained cold pattern building for NW Europe. We'll have the odd rogue run or not so cold run I'm sure next few days, but it's certainly exciting times. Same again tomorrow!!

[Geordiesnow]

I think unfortunately its a case of, because its the UK, our luck will tell us what the 18Z is showing will happen and totally discounting any previous runs because the other runs are too good to be true. 

I'm happy with the 18Z run in general though, the west based NAO has been talked about on here and it can't be ruled out but at this moment in time, its too early to say and as i said earlier, it will unfortunately be a few days before we know for certain whether its going to be a shortish blast of cold or perhaps something a bit longer. 

[Mark Parsons]

2 hours ago, mcweather said:

The great thing about Greenland highs is they can lead to charts like this

And remember what happened that day don't we mcweather!!

[booferking]

Well the fax chart have the 528 Dam Line nearly in the midlands by 94hr then a straight Northerly 120hr smashing one would say

[marksiwnc]

Just now, phil nw. said:

Relax guys tonights day 5 fax

 

It's on track.The broad pattern for next week is for cold.

The next frame on the fax would be full of amazing potential I think with all the fronts and trophs waiting in line.  #waitforit 

[bradymk]

Haha one day they'll stop the GFS at +240, one day....

[Smiler1709]

Some people are absolutely ridiculous, it's one run against the lot. Will change by tomorrow morning so have a chill pill and go to bed. Great evening of informative model info, and fantastic cold charts. Lovely stuff. Night all. 

[Kentish Snowman in Yorks]

It is clear from the previous ensemble suites churned out by the GFS earlier today that some 'less cold' solutions were being toyed with in FI and it just so happens that one of those has now appeared on the 18z op.

I see no cause for concern though as the broad pattern remains the same and I for one am very confident we are about to experience a decent cold spell which just might even involve some of the white stuff!