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

[tight isobar]

Its nothing to do with the 18z

Nor' the gfs and all of its suites showing wintry weather becar at times its in abundance!  

However the point 'marked' is its at regular times of late' bizarre phasing, evolution'blind-mis-matching. .and eventual fruition. 

To name a few!!!

I've personally always referred to it as the wobble model..

Although "given" at time is bang on the money...but at times is said at best...anyway be interesting to see compare on all 00z suites.

[A.J]

thank goodness the models don't dictate the weather eh?.......too many people looking for things to go wrong based on computer algorithms reliant on the data entered which is already several hours out of date by the time we see the output......I've a horrible feeling that some poor souls will spend hours on here next week pouring over the model output in dreaded anticipation of the end of the cold spell whilst blissfully unaware that in whilst doing so, 6 inches of snow has fallen and they've missed every flake......there's a message there somewhere! 

[feb1991blizzard]

1 minute ago, ajpoolshark said:

thank goodness the models don't dictate the weather eh?.......too many people looking for things to go wrong based on computer algorithms reliant on the data entered which is already several hours out of date by the time we see the output......I've a horrible feeling that some poor souls will spend hours on here next week pouring over the model output in dreaded anticipation of the end of the cold spell whilst blissfully unaware that in whilst doing so, 6 inches of snow has fallen and they've missed every flake......there's a message there somewhere! 

If theres 6 inches trust me i wont miss it, but i cincerly doubt there will be - more likely mid feb if we get an SSW.

[Mucka]

GFS 18z ensembles for London(ish) Double digit temps for the 16th? Op run) I think not.

Edited January 7, 2016 by Mucka

[swilliam]

9 minutes ago, Mucka said:

GFS 18z ensembles for London(ish) Double digit temps for the 16th? Op run) I think not.

 

Hope (and expect) that you are right - what a let down that would  be.

[radiohead]

5 minutes ago, swilliam said:

Hope (and expect) that you are right - what a let down that would  be.

But quickly followed by an ice day on the 18th!

[Neilsouth]

On 06/01/2016 at 11:09 AM, Neilsouth said:

I've spent the past month trying to get access to the site after forgetting my password, turns out it was the username isn't the original one ooops!

 

Anyway back on topic, it makes a change to see models like this and staying like this when you wake up first thing in the morning, but my question is what stops the low pressure over the uk next week, staying over the uk or filling. And not allowing the cold to filter south?

I posted this on the 6th and was completely ignored, yet looking at some of the models this seems to have happened? Or am I reading the models wrong

[londonblizzard]

One GEFS 18z perturbation bites the bullet and goes for -14 uppers in fi. Obviously cherry picking, but still a decent set, although warmer on average than the 12z. Still a huge amount of uncertainty about what happens from 16th Jan onwards, lets hope we confirm on the cold options over the next few days.

Edited January 8, 2016 by londonblizzard

[Mucka]

GFS not backing down, in fact is a little bit further West still than the 18z out to 108. Surely it can't be as messy from here though.

UKMO not backing down either so far out to 96h

Edited January 8, 2016 by Mucka

[Ali1977]

Huge differences at just 4 days away, hopefully UKMO has a better grips of the heights into Greenland.

You can't discount any at 96 hours out, but one must be way off the mark...

Edited January 8, 2016 by Ali1977

[Mucka]

144 comparison GFS/UKMO

GFS looks safe enough with the Azores low behaving itself and rebuilding of the Atlantic ridge, shortwave just S of Greenland may come into play though.

 

UKMO rather different with high toppling to far East if anything. Something in between would be good  

Meanwhile GFS goes on to develop a beautiful Greenlnd high but of course it needs to push the Azores spoiler low NE toward us building heights to the South. Very close to absolute classic snowfall but also a washout. Certainly more interesting than UKMO if you have the heart for it.

Just crazy how hard it is to just get cold setup for the UK without a thousand potential spoilers popping up on the way.

JMA only goes out to 84 but worth showing given the differences between UKMO and GFS - it is somewhere between the two which is probably where we want to be.

Edited January 8, 2016 by Mucka

[Ali1977]

+4c 850s into the south by next Saturday on the GFS - let's hope it gone wrong...Way different than its last runs creating a huge Greeny high, unfortunately not assisting us though....Also way different than the UKMO. I'd be surprised if this is correct, although the ECM may give us an idea in a few hours...worryingly it looks similar to the METOs 6-15 day wording however.

FI may reload though.

Edited January 8, 2016 by Ali1977

[tight isobar]

Huh!..tgen again I may just re-vert to the former. ..

Is someone injecting LSD into this output! !!!

[Roger J Smith]

With that Azores low in the scenario, I feel that any given model run is probably no more accurate than, say, looking back at some random year in the past or spinning a wheel. The Azores low has intruded itself into various model runs for days now with every imaginable outcome and seems destined to continue this for a few more days yet. My hunch is that this 00z GFS will look nothing like the ECM or the GEM and that reality will then look a bit like an average of all three.

[tight isobar]

If the 00z ecm starts to align with the gfs' its a three cool/cold snap at best.

If its carries on where it left its 12z suite (which it should) 

Im discounting 100% of the gfs output upto and into any should be cold spell. ...im off to bed!

[Mucka]

GEM having a wobble too with having the pattern to the West, a messy trough and bringing the Azores low into play. Never gets particularly cold at all.

I really hope ECM doesn't go this route.

Edited January 8, 2016 by Mucka

[Ali1977]

Still affair few very cold ensembles and day 10, although a fair few that are already mild by day 10....and UKMO is looking good at 144, whilst the GEM follows the GFS although still looks full of potential into FI....

mmmm, not the best start for us coldies today...ECM is going to be interesting!!

[terrier]

So it's looking like a 3/4 day cold spell before milder air moves In again looking at the gfs output. I think the gfs picked this up on Thursday nights 18z run thought it was an outliner but looks like it may have picked up the correct signal. And I'm wondering if it's showing something similar to mogreps because it looks to tie in well with the met outlook. Interesting ecm coming up that's for sure.

[Abyss]

Gfs has been up and down like a yoyo over this past couple of days. I await the ECM 

[Captain Shortwave]

Well I really don't know what to say this morning. I actually don't have  a clue on how this will pan out at all. Far too many short range variable that the models simply do not have any agreement on. First of all that ridge in the Atlantic, secondly the upper trough over the UK and Scandinavia and thirdly that low over the Azores. To be honest the wording of the BBC/Metoffice forecasts really doesn't give me too much confidence in the outcome apart from that cold air will spread erratically southwards at the beginning of next week. Specific detail still in major question here.

So the output (UKMO days 4/5/6 day charts, the GFS and GEM are day 4/6/8 charts)

UKMO

Given the volatile output, the UKMO is actually quite similar to yesterday afternoon in the overall evolution. This is one I would want to happen, the cold shot is here earlier and more potent and whilst there is no high latitude block we do again have scope at day 6 to re-amplify that Atlantic ridge triggered by that deepening low off the Eastern Seaboard. A good run overall and doesn't backtrack either which is a surprise to be honest.

 

GFS

Well the block is better than the 18z was, but the output in broad terms is fairly similar with a slow moving trough over the UK which only slowly allows cold air to filter across us. We quickly form a cut-off high over Greenland which allows the jetstream to move underneath it. This engages that Azores low instead of the trough over the UK and Scandinavia, though this does happen later curving the jet north east. The second half of next week is pretty cold though.

 

GEM

This is even more extreme than the GFS is terms of developing those high latitude ridges. It all goes wrong due to an area of cold pooling moving south west from the upper trough over us which quickly engages that low over the Azores. At which point it is game over for the cold spell as the jet aligns north east through Europe. The 7-10 charts unbelievably re-establishes the Euro slug. At least we can't take that too seriously.

 

So overall some huge differences between the models. I can't call things either way apart from I hope the UKMO raw data is somehow on the right track here.

 

Edited January 8, 2016 by Captain Shortwave

[Mucka]

GFS 00z ensembles central England

Cold snap then plenty of scatter but GFS is just one model and even within its ensembles there are several runs going more prolonged cold so there is no way to sensibly call this a 3/4 days cold shot only yet - in fact if the ECM does not go the way of GEM or GFS then the evidence still leans toward a minimum of 7/8 day cold spell.

Let

[Liam J]

Somethings got to give soon!! Was hoping to wake up to see the GFS looking very different but that hasn't happened... It never really gets that cold either before the Atlantic fires up and turns into a nightmare for the flooded regions. Really want it to be very wrong but at the same time I don't think we can discount it 100% as it's not backing down (yet), remember last week when the UKMO was going for an undercut to Scandi heights and the GFS wasn't interested, the UKMO undercut never happened.... 

[radiohead]

1 minute ago, *Sub*Zero* said:

Somethings got to give soon!! Was hoping to wake up to see the GFS looking very different but that hasn't happened... It never really gets that cold either before the Atlantic fires up and turns into a nightmare for the flooded regions. Really want it to be very wrong but at the same time I don't think we can discount it 100% as it's not backing down (yet), remember last week when the UKMO was going for an undercut to Scandi heights and the GFS wasn't interested, the UKMO undercut never happened.... 

Perhaps it is something to do with it's resolution, but I have noticed before the UKMO is often the last to "back down" when it comes to failed cold snaps.

Agree that the GFS cannot be ignored now with two runs back to back and the majority of the ensemble suite backing the det's evolution of events around Greenland now.

[Captain Shortwave]

Regarding last week, to be honest there was never really any model backing that easterly, we saw one UKMO run do it and the occasional GFS ens member but that seemed to be scatter rather than a general trend. At least here the UKMO seems to have chalked up a few consistent runs apart from yesterday morning.

I stopped looking at the GFS ens at around day 4 this morning because to be honest, the ens don't have a clue on how that secondary system interacts with the parent low over the UK at that time frame, we have evolutions close to the UKMO and other mad solutions bringing storm force winds to Germany/Denmark at 4 days out, as well as solutions close to the operational.

 

ECM out to day three, it has the secondary system south of Ireland. At this time the UKMO has this over Brittany and the GFS has a shallow wave running through central France. 

To be honest looking at it I suspect the ECM is pretty close to its 12z operational yesterday so far.

Edit - Well in the end it is pretty close to the GFS at day 4/5. Damn....

Edited January 8, 2016 by Captain Shortwave

[The PIT]

Yes the signs aren't good Liam. Beginning to look at more of a model deep FI/FI tease which will disappear by the time it gets into the reliable time frame. Everything setup for eggs on faces as Beeb saying winter properly arriving well ahead of the event.

At the moment I would say 50/50 of it turning rather cold 10/100 very cold with the odd ice day thrown in.