Model Output Discussion 29th December - Into mid-Winter.

[SMU]

5 hours ago, northwestsnow said:

Chin up Steve we are in your corner

Hopefully the ecm will pull a rabbit out of the hat but your 'slayer' tag for the UKMO is looking spot on, i can think of a few other descriptions for the UKMO but i would probably breach the swear filter!!

Morning All

my last post pre new year - im afraid its over the Ens will catch up this eve -

 The GFS is now a carbon copy of the ukmo solution from yesterday with zip cold coming our way

the lesson being once again unless all 3 models show cold the  back the mild one

I wish everyone a happy new year !

S

 

 

 

 

 

 

 

Edited December 31, 2016 by Steve Murr

[Day 10]

The big 3 at 96 look fairly similar now:

But then at 120, the ECM looks more the odd one out now to me, the area around southern Greenland:

Pointless going any further out than 120.

[Cloud 10]

Huge slab of frigid air over much of Europe on the day 10 ECM ens.

 

[Guest]

My wife has Bi Polar and i can safely say this thread is totally Bi Polar/BPD... i can sell you all some meds if ya like.... just one run tho so bare in mind that the 12z suite could so easy flip back again... (bit like the wife) and as has been said before when the weather is not default zonal we always get these wild swings as the models struggle to get it right... Sure Jan 2013 was a bit like that.. wild swings and plenty of its over posts etc...

[karlos1983]

2 minutes ago, IDO said:

Neither the control or mean support the northerly; a big shift towards the op but not as progressive:

That's an oxymoron IDO surely? How can it be shifting toward the op if it's not as progressive? It's just showing a slightly different variation.

Edited December 31, 2016 by karlos1983

[Jason M]

Still some support for the northerly within the GEFS at 168 but tbh the suite as a whole is not convincing. I suspect the opp will be leading the way in the mid term. Heights seem much stronger to our south on many of the ptrbs than we were seeing yesterday. The trend is clearly not our friend at this point.

[radiohead]

No GFS(P) since 12Z yesterday?

[Banbury]

That will do nicely ..................if only

[Zakos]

22 minutes ago, karlos1983 said:

Actually I think "bi polar" describes the weather better than this thread or its members. We just go up and down with it. Totally normal if you ask me when reactive to nwp models, which change in the GFS case, 4 times a day! Unhealthy would be a better way to discribe this forum, much like alcohol, but try going  week without either....

I myself have learned this year to never get too excited about anything beyond 144, and especially to assess model output as a whole over 12 hour intervals. The other models dont have 06z/18z runs so there is nothing to compare it to at that given time.

The ECM and GFS means still support the Northerly

06z operational is clearly going to be a mild outlier.

A lot of people seem to be convinced that the models have crystal balls.... if the 06z does not even have support from its own ensembles.... how can you use that single model run to write off the next cold spell?

Insanity in my opinion. If the GFS and ECM 12z means both swing away from the northerly, then I would be worried, Until then, pretty much as you were... cold and blocked outlook.

Deep cold and snowy conditions remain a low risk but the possibility is still there. Some snow showers, possibly heavy in some areas, are still possible from this second northerly. the snow may well remain as high pressure is set to take over, could maintain snow cover for days.

Outlook is promising, but nothing set in stone. 

Edited December 31, 2016 by Zakos

[karlos1983]

Flicking through the individual purbs at 192, that is going to be one pretty ensemble chart when it comes out... scatter springs to mind!

[chapmanslade]

3 minutes ago, Ed Stone said:

Does that mean that the op and control have exchanged places, within the mass of entangled chaos that exists, past about T+144? 

It does exactly that. As has been said many times before, operational runs beyond T+144 flip and flop and getting excited or otherwise about them really is pointless. There is a 20C range in 850's on the GFS ensembles at day 10 - does that not ring alarm bells about how much credence you should give them.

[Banbury]

There are several Easterly options in the ENS after 192, don't rule it out ...................yet

[jimben]

55 minutes ago, booferking said:

Thats the same outfit that is going for Northerly to North Easterly this weekend coming with wintry showers spreading South..

That's the one

[karlos1983]

Just now, Banbury said:

There are several Easterly options in the ENS after 192, don't rule it out ...................yet

Yes there are certainly more cold options than mild, but all quite different. So I remain positive.

[bluearmy]

This isn't bad as a statement of where we are day 8 from the 06z gefs

most favoured spot for the upper ridge centred is just west of the uk and the trough over e Europe.

uncertainy in both directions either side which could be lower or higher heights

 

[karlos1983]

Surprise surprise the op was off on one before the end of the hi res

 

ECM ensembles not looking as good as yesterday 12z it must be said though. Much water to pass under the bridge. Sigh...

Actually they have added -10 to the graphs, which threw me. Perhaps not so bad on closer inspection.

im off for a lie down 

 

Edited December 31, 2016 by karlos1983

[Summer Sun]

4th to the 6th the Op is on the colder side of the mean 7th onwards it's on the warm side

[Zakos]

The "roller coaster" of model watching can be fun at times, especially when trending towards cold and snow.

However, at times like this, with considerable uncertainty, it is best to take a step back and view all model outputs, and not to take anything beyond 144 too seriously from any model output.

The 12z GFS may predict mouth-watering northerlies and easterlies, packed with copious amount of countrywide snowfall.

That it in itself would mean nothing, just as the 06z GFS means nothing. It is a forecast, not a prophecy... It can and will change.

Anyone getting frustrated... try just focusing on output within 144+... it will make the whole process of model watching a lot more clearer and enjoyable.

 

 

 

Edited December 31, 2016 by Zakos

[Scandinavian High.]

So is that it then game over for cold and snow 06z gfs.

Edited December 31, 2016 by abbie123

[Catacol]

For those wondering what all my talk of -PNA might mean (I'm aware I've been saying it a lot without too much explanation) here is the key info for you: From the University of California - this:

"The Pacific/North American teleconnection pattern (PNA) is one of the most recognized, influential climate patterns in the Northern Hemisphere mid-latitudes beyond the tropics. It consists of anomalies in the geopotential height  fields (typically at 700 or 500mb) observed over the western and eastern United States. It is important to note that the PNA has been found to be strongly influenced by the El Niño-Southern Oscillation (ENSO) phenomenon. The positive phase of the PNA pattern tends to be associated with Pacific warm episodes (El Niño), and the negative phase tends to be associated with Pacific cold episodes (La Niña)."

We are now in a Nina atmospheric state and hence we are in -PNA territory. The interest for me is the depth of that negativity. We are forecast to hit -400 by next weekend as you can see if you click on this link

ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/4indices.png

... and this is fairly rare. Have to go back 3 years to find a -400 reading.... and such a long run of predicted negative values is also not the norm.

What does this mean? Well - here is the global composite produced by Uni California to help explain the above:

 

One of many signals suggesting we should not let ropey op runs get under our skin yet.

[karlos1983]

1 minute ago, abbie123 said:

So is that it then game over for cold and snow .

No lol, still December. 2/3rds of winter still to come. 

[Summer Sun]

Full 06z ens

[Zakos]

1 minute ago, abbie123 said:

So is that it then game over for cold and snow .

A horrid 06Z for sure, however 6 hours ago the GFS was going for a northerly where now it wants to bring in a south westerly.

This is only at 168 hours out, the difference between the runs is astounding.

A step back for sure... but with such huge swings in model output I wouldn't take anything seriously from the models to be honest.

Huge differences even at 120, FI is 96 hours in my opinion

 

[cheshire snow]

Just now, Steve Murr said:

Morning All

my last post pre new year - im afraid its over the Ens will catch up this eve -

 The GFS is now a carbon copy of the ukmo solution from yesterday with zip cold coming our way

the lesson being once again unless all 3 models show cold the  back the mild one

I wish everyone a happy new year !

S

 

 

 

 

 

 

 

Hi Steve

I read your posts regularly and have learnt a lot from you.however your post has left me some what confused "I'm afraid it over"what is over,nothing has begun has it?

 C.S

[Man With Beard]

13 minutes ago, Summer Sun said:

Full 06z ens

7 runs still go below -10C at some point.

Perspective - I don't think we've had more than about 10 or so members go below that line on any one run.

All that's happened is a few more runs have gone full zonal instead - about 5 yesterday, closer to 10 on this run.

It's the GEFS for crying out loud - it's rarely going to give a 100% consistent signal run after run! Just a general trend. 

Long way to go yet

Edited December 31, 2016 by Man With Beard