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

[Bullseye]

This shows mid-Jan cold spell of 1958, which was during a strong el nino and W-QBO but probably more important this period also produced impress Kara Sea high. Classic west based -NAO is this?

Edited January 7, 2016 by Bullseye

[Djdazzle]

1 minute ago, Geordiesnow said:

The UKMO 12Z run is an outlier, the ECM has backed down towards more the GFS set up of having the troughing over the UK for much longer instead of clearing out in the North Sea, and even this morning's UKMO run had a slower moving trough over the UK and the result was something similar to this afternoon's ECM run. 

The disagreements also start as early as 72 hours regarding the positioning of the trough with both GFS/ECM looking closer together than the UKMO positioning of the trough at 72 hours. I'm not saying the 18Z is nailed regarding the medium term of its run(no one will know what will happen at this range) but the problem with a slower moving trough is its delays the colder air to get to us, it creates a larger mild sector consequently we end up with more modified colder air. The UKMO run is very clean and colder air will shoot down to all parts by Monday evening on that run, its a small but big difference and its why I was pleased with the UKMO run but it will be a miracle in respect if both the GFS and ECM backs down now. Its certainly not impossible but unlikely. 

I wouldn't trust anything beyond T96 at this stage. But it's the GFS that is out on its own at the moment. Yes, it may be right, but it's evolution is at odds with pretty much everything else.

[Tom Jarvis]

Hi all just want to add something to the tread that I remember from the a few years ago. It regards the fateful period of the so called failed easterly and THAT ECM. But which model wasn't having any of it, I think it was the UKMO but could be wrong. So what I am saying is that it is not the first time the UKMO has got onto something and them had the other models come into line with it as well. Also I remember that when model viewing and if something was on the horizon that the models were showing something cold that when it got into the timeframe for the UKMO and wasn't there everyone rightly worried about it and the other models were dragged into line to what it was showing. This time we have the UKMO showing the best cold and the others are lagging slightly behind. Also which run had been most consistent up to t144 the UKMO.

[Mark Neal.]

3 minutes ago, ukpaul said:

That's of no real use, it's not its internal consistency that matters, it's consistency as related to other models that we don't have; as I pointed out with regard to NOAA, there is none. That's not to say that GFS can't be right, but it means that someone else must be wrong. 

I'm in total agreement with what your saying. GFS been questioned for a while for its constant flips, Americans arent the fondest of there own weather model judging by tweets and discussions.

The mean will be interesting see how many members agree /disagree generally with the 18z. 

Edited January 7, 2016 by Mark N

[Harsh Climate]

Well looking at the esembles at 138 hours, what a whole host of variations!

Perpetrations 5, 10, 11 and 13 aren't too shabby. 

 

Case closed. Hope I don't have to wheel out that it's a a single run with no support post out again 

 

Edited January 7, 2016 by Harsh Climate

[Mucka]

Bit of a worry how many GFS ensemble members want to flatten the ridge by 144, this really should be resolved by now.

 

Also ECM London ensembles very good but a little too much scatter to say a prolonged cold shot is nailed on.

[weirpig]

4 minutes ago, swilliam said:

err - they are the same?

 

5 minutes ago, swilliam said:

err - they are the same?

Hang on no   theres a shortwave over   Iceland!   whoops  sorry dogs molting

[Geordiesnow]

7 minutes ago, mountain shadow said:

And what about the boys and girls at NOAA?  Do you think they'll be trumped by a pub run too? 

I've no idea what they will say regarding any ridging/WAA into Greenland or the pattern they expect at the States and I very much doubt they will be talking about the troughing over the UK. 

I think there is a mis-understanding here, I'm not believing for a second that the whole 18Z run will be what will happen as I think it does go off on one and becomes too messy as the GFS usually does but I'm not discounting on what it wants to do with the troughing which as I said many times that its been the only model which wants to keep the troughing over the UK for quite a bit before eventually clearing. 

If the troughing does become persistent, then we can only hope the ECM is right regarding its heights around Greenland as the cold should eventually come and then a day or two delay won't be a bad thing but you don't want a situation where the trough is so reluctant to move, it stops the cold air from flooding in at all. 

[swilliam]

2 minutes ago, Harsh Climate said:

Well looking at the esembles at 138 hours, what a whole host of variations!

Perpetrations 5, 10, 11 and 13 aren't too shabby. 

 

Case closed! Hope I don't have to wheel out that it's a a single run with no support post out again! 

 

Well unfortunately there are quite a few supporting the OP as well.

[ItNeverSnowsInWindsor]

What an evening of dream charts, especially the JMS at T240 - pure heaven - if this comes in S England could see copious amounts of snowfall with the shortwave hitting the deep cold air in place!

[Harsh Climate]

2 minutes ago, swilliam said:

Well unfortunately there are quite a few supporting the OP as well.

 

The mean isn't too bad

 

[Djdazzle]

1 minute ago, swilliam said:

Well unfortunately there are quite a few supporting the OP as well.

There are, but the amount of wild scattering pretty much sums the run up.

[bobbydog]

6 minutes ago, bigsnow said:

Lets put it another way if all the other models were showing Mild weather and the Pub run pulled out a cold run everybody in here would be saying oh its the pub run its off on one dont pay any attention to it as it will never happen... so why are so many people taking it so seriously tonight????

because its showing that there is still not solid cross-model agreement. it doesn't mean its right of course but we've had so many let downs in the past, people cant relax until all the models show snow for the whole country at +12hrs. 

it snowed for roughly 3 minutes here last year. even 3 days would be nice now!

[rory o gorman]

17 minutes ago, mountain shadow said:

And what about the boys and girls at NOAA?  Do you think they'll be trumped by a pub run too? 

You do realise they can change their output overnight , I have a number of friends that work in the NWS and they often follow the ECM raw output as it models the midwest and eastern board rather well. 

[stewfox]

1 hour ago, PolarWarsaw said:

 

We have overall edged away from dramatic cold, truly exciting SNOWY charts today somewhat. So to me it looks like a cold spell at first...with a 50-50 chance of either mild/atlantic or something truly epic coming thereafter. As they say, let's get the cold in first and see what happens from then on in/

Plenty of model watching to come methinks folks!

Yesterday it was 10% chance of epic charts today we have edged away from that to 50%. Happy with that

Edited January 7, 2016 by stewfox

[Geordiesnow]

8 minutes ago, Djdazzle said:

I wouldn't trust anything beyond T96 at this stage. But it's the GFS that is out on its own at the moment. Yes, it may be right, but it's evolution is at odds with pretty much everything else.

Well i'm starting to believe the troughing will be more slow moving than some models initially thought therefore a delay to the colder air, one will hope it won't be as slow and as far west as the GFS so the cold air will have more of a chance to filter down from the NW. Hopefully the ECM will be right regarding the ridging side of things and the cold that follows. 

Unfortunately a slower moving trough over the UK will also mean further likelyhood of flooding whereas if it heads into the North Sea quicker like yesterdays ECM/UKMO runs hinted at, then it will be less of an issue! 

[Weathizard]

Absolute mess in the ensembles, even at 144 the amount of variation is quite astonishing, GFS isn't dealing well with this at all at the moment.

further runs needed... ONCE AGAIN!!

[bradymk]

Life would be much easier if the GFS didnt exist at times. It adds so much stress to model watching. Not a great 18z run again but the ensembles are better, perhaps not as good as previous suites though but wouldn't read much into either to be honest. Best bet here is too head to bed and wait for the 00z's euros. Hopefully we'll have more agreement by this time tomorrow...

[Singularity]

Seen the odd MJO outlook from GEFS raised already this evening, and wholly agree that it makes the GFS and GEFS output highly suspect; the impact on the behaviour of key troughs and consequentially blocking features are just too large to ignore.

The form horse is continued steady progression of the MJO, but at an amplitude often a bit above what ECMF shows.

That would have the potential to keep GLAAM skyrocketing for even longer than any model has yet shown, which would probably make the output even more dramatic. I expect GEFS will be very wrong to have the GLAAM falling so much in week two, though this expectation is far from infallible I know.

Worth bearing in mind, though, that this still leaves room for the NAO to (eventually... in 10 to 14 days perhaps) become too-west based to maintain the cold all the way to month's end. This wouldn't be game over though, as wavelength changes in Feb favour a return east, as Tamara has highlighted in one of her typically informative posts of late.

 

As a side-note, the issue with GEFS also means we may  not have the right guidance at play for days 11-16 with respect to stratospheric developments. Interesting potential there but at the moment just that - potential.

Finally for now, I see the 18z literally goes bowling with the Azores low! Most amusing...  but what the model then does with the blocking totally isn't. Here's hoping the MJO does continue it's current form and we can enjoy the sort of setup the ECM det. has produced for us this evening in the +192 to +240 range. No surprise that the rather similar JMA run is supported by a very similar MJO outlook.

[Mair Snaw]

2 minutes ago, stewfox said:

yesterday it was 10% chance of epic charts today we have edged away from that to 50%. Happy with that

Brilliant.....lol

Edited January 7, 2016 by bigsnow

[Man With Beard]

Funny, I just flicked through the GFS 18z and thought it was OK for wintry weather. A spell of cold uppers, then a snow to rain to snow event, then even colder uppers to follow after. The cold here only leaves at T250 odd which is so far out and unreliable it should be banned anyway. Makes a change from 15C and endless cloud?

[Harsh Climate]

2 minutes ago, Weathizard said:

Absolute mess in the ensembles, even at 144 the amount of variation is quite astonishing, GFS isn't dealing well with this at all at the moment.

further runs needed... ONCE AGAIN!!

 

While the UKMO and ECM are firmly on board I'm not getting strung out over 50% of the pub runs esembles been less good.

[swilliam]

8 minutes ago, Harsh Climate said:

 

The mean isn't too bad

 

Yes it is still pretty good but not as good as the 12z. I think this run just shows that it is still possible for it to go wrong. 

 

I am going to stick with the ECM mean and hope it is still like this in the morning.

 

The GFS threw out a funny run on the 18Z last evening.

Edited January 7, 2016 by swilliam

[Stormeh]

Chin up guys, this happend with the 18z last night. The GFS is all over the place, I am sure tomorrow's charts will be back to what we want to see!

[Geordiesnow]

10 minutes ago, Weathizard said:

Absolute mess in the ensembles, even at 144 the amount of variation is quite astonishing, GFS isn't dealing well with this at all at the moment.

further runs needed... ONCE AGAIN!!

But nor has the ECM/UKMO. ECM forecasting a big Azores low to come through(fairly similar to how the GFS18Z is forecasting it) on this mornings run yet by this afternoon run, its no where near in play anymore. The UKMO this morning has an output similar to this afternoons ECM run but now it has an output which was fairly similar to yesterdays UKMO runs but unfortunately at this moment in time look quite a bit out of line. 

The GFS medium term chops and change with each run, nothing new there but unfortunately its sticking to its guns of a slow moving trough which affects how quick and potency any cold get, now it might not matter if something like the ECM 12Z is right as the cold air will eventually come in but the 18Z is a bit of a warning what a delay to the cold air hitting us could do if all the other pieces of the jigsaw don't fully come together. 

Edited January 7, 2016 by Geordiesnow