Model Output Discussion 1st January 2014-06z onwards.

[Interitus]

 

 

The ECm Ensembles is the outlier- not the operational or control-  they will be generally 24 hours behind the pattern trending- with the GFS usually 48 hours or so.

 

 

S

 

It is by definition impossible for the ensemble mean to be an outlier. If the operational (strictly speaking not part of the same solution set because higher resolution) or control are different, they are the outliers. If they prove to be correct, then the ensemble mean may lag behind them, but they are still outliers (originally).

Edited January 8, 2014 by Interitus

[nick sussex]

Looking at the UKMO further outlook that's for me borne out of simply looking at the ensemble means which will often wash out the more amplified solutions, mention however of wetter in the south and sw is a clear indication of some trough disruption, drier in the east means they expect the ridge from Scandi to be in evidence and the energy to be tracking se along the western fringe of the UK.

 

That outlook in no way is showing a continuation of the current status quo at least for a  time, then they expect the jet to renew and go over the top, this is dependent on the upstream pattern becoming more zonal and flatter but even then the location of the high could still serve to split the jet.

 

The issue even if you don't buy a clean easterly is that even the ECM ensemble mean would likely bring some quite significant snow to certain areas, but again that will wash out the more amplified solutions.

 

Personally the outlook from the UKMO is sitting on the fence and seeing as the only people that generally read it is us  or weather anoraks from other forums then no ones going to  accuse them of going over the top.

[EML Network]

How can you say that with any confidence, a week ago it was westerlys ALL THE WAY.  Having said that, let's get there first and worry about elongation or not next week.

 

BFTP

 

You have essentially answered your own question , if it was Westerly's all the way only one week ago, then this cold interlude is likely to be just that. ..an interlude.

 

With Westerly's following on closely behind, perhaps a pattern change to something longer lasting at the end of this month A'la MET O.

 

And observations don't need to be made with confidence do they ? they are only observations.

 

Besides the 06z Ensembles back me up as does the final frame of the ECM. ..I haven't yet looked at the ECM ensembles but I suspect they too will paint a broadly similar outcome.

[Purga]

Looking at the UKMO further outlook that's for me borne out of simply looking at the ensemble means which will often wash out the more amplified solutions, mention however of wetter in the south and sw is a clear indication of some trough disruption, drier in the east means they expect the ridge from Scandi to be in evidence and the energy to be tracking se along the western fringe of the UK.

 

That outlook in no way is showing a continuation of the current status quo at least for a  time, then they expect the jet to renew and go over the top, this is dependent on the upstream pattern becoming more zonal and flatter but even then the location of the high could still serve to split the jet.

 

The issue even if you don't buy a clean easterly is that even the ECM ensemble mean would likely bring some quite significant snow to certain areas, but again that will wash out the more amplified solutions.

 

Personally the outlook from the UKMO is sitting on the fence and seeing as the only people that generally read it is us  or weather anoraks from other forums then no ones going to  accuse them of going over the top.

But Nick they talk about outbreaks of rain mainly affecting the NW and the best of the drier weather the SE not to mention "Some periods of colder weather are likely, particularly inbetween weather systems, but overall temperatures may well remain near normal.

Updated: 1159 on Wed 8 Jan 2014"

 

this indicates a westerly cool / mild regime rather than anything particularly wintry so a move away from the recent hints at a more significant cold setup after month's end.

[BLAST FROM THE PAST]

bftp,this is indeed what the models are showing, both gefs & ecm extended. As ever, all we have are the models. So members can of course question the longevity if that is their wish, its all part of model discussion after all. I agree, broadly with your closing sentence, but it is a valid observation from EML.

Some models are showing, the same some models that weren't having anything other than westerlys.  Its not questioning that I'm pulling up on but the 'statement that westerlies ARE returning after 3-5 days, that is wrong as it may or may not be.  GEM disagrees for example, nothing is a given

 

BFTP

You have essentially answered your own question , if it was Westerly's all the way only one week ago, then this cold interlude is likely to be just that. ..an interlude.

 

With Westerly's following on closely behind, perhaps a pattern change to something longer lasting at the end of this month A'la MET O.

 

And observations don't need to be made with confidence do they ? they are only observations.

 

Besides the 06z Ensembles back me up as does the final frame of the ECM. ..I haven't yet looked at the ECM ensembles but I suspect they too will paint a broadly similar outcome.

No, it means the models canot be taken at face value but they have been trending colder. Waht's interesting is that we haven't had a sudden burst to perfection and withdrawal but a build up to better and better.  That 'could' be relevant to the cold spell.  I'm waiting to see where we are come Monday, we may know then if 3-5 days is what we'll get or more.

 

BFTP

Edited January 8, 2014 by BLAST FROM THE PAST

[Jason T]

Well fantastic show so far and 495 users, I'm staying logged in, Come 3 pm it will probably be 800 + and can't get into thread as that's when the real fun starts right up till pub run. Ruins your nerves this game.

 

 

I know it's NASA Model,Who cares let it join the party.

 

[shetland islands]

The recent change in the models is just one option to explore and therefore, it is currently low confiendence. This is why the UKMO will not RAMP any cold/snow prospects until future runs confirm a patter change. The models, will, of course, chop and change over the coming days.

[Cheshire Freeze]

Some models are showing, the same some models that weren't having anything other than westerlys.  Its not questioning that I'm pulling up on but the 'statement that westerlies ARE returning after 3-5 days, that is wrong as it may or may not be.  GEM disagrees for example, nothing is a given

 

BFTP

No, it means the models canot be taken at face value but they have been trending colder. Waht's interesting is that we haven't had a sudden burst to perfection and withdrawal but a build up to better and better.  That 'could' be relevant to the cold spell.  I'm waiting to see where we are come Monday, we may know then if 3-5 days is what we'll get or more.

 

BFTP

 

If we get ANY extension of heights towards Greenland then you can forget zonal for the rest of the month. It would be goodnight Vienna for it. However if we don't see this it's perfectly plausible that the E'ly could be a relatively short lived affair.

 

Heights towards Greenland...

 

[mountain shadow]

The recent change in the models is just one option to explore and therefore, it is currently low confiendence. This is why the UKMO will not RAMP any cold/snow prospects until future runs confirm a patter change. The models, will, of course, chop and change over the coming days.

No one expects the Met Office to ramp anything.

 

I do however expect them to look at the available information which currently points towards a much colder regime and at least mention the possibility, even if its uncertain. That's forecasting isn't it?

 

If not even fence sitting, as it doesn't even mention the chance of a colder spell for the South, that for me says they don't expect any cold easterly setting up.

[shetland islands]

 

No one expects the Met Office to ramp anything. I do however expect them to look at the available information which currently points towards a much colder regime and at least mention the possibility, even if its uncertain. That's forecasting isn't it? If not even fence sitting, as it doesn't even mention the chance of a colder spell for the South, that for me says they don't expect any cold easterly setting up.

 It will be mentioned, but probably not until Friday - if the models are still showing a change to colder weather.

[winterof79]

 

No  real snow ramping from METO today for next week

 

UK Outlook for Monday 13 Jan 2014 to Wednesday 22 Jan 2014:

Although showers and longer spells of rain will continue to affect the UK, conditions are not expected to be as stormy as those of recent weeks. At first, the strongest winds and heaviest rain are most likely in the west of the UK, then perhaps in the south and southwest, whilst the east will hang on to the driest weather. It will become colder, especially in the north where there is an increasing risk of snow, mainly over hills, with nearer normal temperatures at times in the south, and an increasing risk of frost, ice and fog. Later in the month changeable conditions are likely to continue, especially in the northwest, with the best of the drier weather in the east.

Updated: 1156 on Wed 8 Jan 2014

 

 

I had just to balance things out a tadIt is however a fluid situation with the METO outlook.They will most probably want to see the 12z output follow the00z before having a minor ramp as it were. 

Edited January 8, 2014 by winterof79

[mountain shadow]

But all the information is showing it now Shetland.

 

As others have said, Joe Bloggs sitting in middle Englandshire would read that and think that no cold is on the way, yet, this time next week might be snowed in, and the possibility is not even mentioned?

 

That's a cop out forecast.

[terrier]

Let's be honest here. Easterleys are the hardest thing for the uk to achieve. I've seen these things go wrong even at t48 so many more runs required yet. As fergie has tweeted it could flip the other way yet. Going to keep my feet firmly on the ground. If it's still showing on Sunday evening I may start to sit up and take note. Until then extreme caution is required.

[nick sussex]

But Nick they talk about outbreaks of rain mainly affecting the NW and the best of the drier weather the SE not to mention "Some periods of colder weather are likely, particularly inbetween weather systems, but overall temperatures may well remain near normal.

Updated: 1159 on Wed 8 Jan 2014"

 

this indicates a westerly cool / mild regime rather than anything particularly wintry so a move away from the recent hints at a more significant cold setup after month's end.

Yes that's though later in the outlook, I'm not disputing that part its too far ahead anyway, I'm talking about early next week and  for the rest of that week.

[shetland islands]

But all the information is showing it now Shetland. As others have said, Joe Bloggs sitting in middle Englandshire would read that and think that no cold is on the way, yet, this time next week might be snowed in, and the possibility is not even mentioned? That's a cop out forecast.

Hopefully the charts will continue with the colder theme. The UKMO tend to forget about us up here in Shetland, we have had a couple of blizzards and storms, but very few warnings or mentions.

[lassie23]

Let's be honest here. Easterleys are the hardest thing for the uk to achieve. I've seen these things go wrong even at t48 so many more runs required yet. As fergie has tweeted it could flip the other way yet. Going to keep my feet firmly on the ground. If it's still showing on Sunday evening I may start to sit up and take note. Until then extreme caution is required.

Agreed, cross model agreement needed before i buy rock salt.

[P-M]

But all the information is showing it now Shetland.

 

As others have said, Joe Bloggs sitting in middle Englandshire would read that and think that no cold is on the way, yet, this time next week might be snowed in, and the possibility is not even mentioned?

 

That's a cop out forecast.

 

 

They would have to hint at people being "snowed" in for that to even be valid - at present the firm details are not in the clear and therefore for an agency which public services are triggered by then to even suggest a snowfest would be inappropriate surely? As always the met have to appear to be on the fence until something more juicy and tangible comes to light... 

Edited January 8, 2014 by P-M

[Mark Bayley]

Has anyone noticed the possible snow event for Monday (albeit restricted to more northern and eastern areas) as highlighted by the ECM? Something to watch on the coming runs if we can get enough cold air pushing east. In terms of longevity i would agree that at the moment it seems more a cold interlude, with the PV relocating back towards Greenland (e.g. ECM), although nothing is set in stone, as shown by the longer range GEM. Either way, with north sea temperatures quite high, overlain by very cold air from the continent, it seems likely that many of us might be seeing our first wintriness of the season so far if downgrades do not occur

Edited January 8, 2014 by Mark Bayley

[Mucka]

An awful lot of spin in here being put on previous forecasts and predictions for mid Jan by some which is to be expected, we all do it. I just hope the output doesn't flip back to something more zonal, that would be excruciating. 

 

I think we can expect the MetO to be cautious and slowly move toward the sort wintriness the models are currently showing if they don't backtrack although there is always the possibility they have data that paints a different picture or at least gives a lot less weight to a possible cold spell.

I think they may have been surprised by the strength of the predicted blocking given their previous comments on the weather type we could expect up to mid month and likely beyond with little weight given to an Easterly flow setting up so early but hopefully they have more confidence in such a possibility occurring now even if their current forecasts do not necessarily reflect that.

 

Very good cross model support for a cold spell developing by mid month today but it will it be the same tomorrow?

I very much doubt it will be plain sailing from here in model land but we are very close to finally seeing our Winter arrive. 

[That ECM]

We have had one set of runs which were very good, GFS 06 was good. What did people expect the meto update to be. If the 12z runs follow on from this morning and tomorrow morning shows consistency then they will show wording which will be more encouraging. Rather than worrying about each word they use, let's enjoy the output as this is by far the most interesting it has been in a long time.

Lucky pants on, so the 12z will be good!!!

[Catacol]

Mid January - things a changing. Spot on for those who saw a winter of two halves.

 

Only 2 charts for me to reinforce the optimism. Here is ECM strat forecast at teh 100hPa level at only 96 hours - this is really pretty reliable in strat terms.

 

 

Note the clear spike to our north showing and opening the door for the pressure rise.

 

Then this one at the end of the run - 240h

 

 

Notice the vortex at the bottom of the strat has started to reform. BUT

 

- There is warming over the UK that will aid with keeping pressure to our north high

- There is a strong signal for troughing to our south

- The vortex is reforming well to the west

 

My interpretation would be - somewhat surprisingly because it has happened sooner and faster than expected - that once the block is established it will not necessarily be a short lived 2 - 3 day affair and we may well see a serious of undercutting lows helping to sustain the pattern.

 

A very optimistic outlook today. My only concern would be that there is an awful lot of latent "heat" lying around western Europe at the moment, and perfect synoptics next week may fail to deliver much apart from cold rain at low levels. We need 2-3 days of easterly feed to get ground and air temperatures down.

[phil nw.]

I suspect we need more runs going the way of the 00z models to calm doubts on the easterly.

There's no denying the ens are showing much colder conditions commencing around the 14th.

 

 

but the period of a slowing jet disrupting near the UK coming against a fledgling eastern block is always difficult for models to work out.

It's a fine balance which ends up the strongest,putting it in laymens terms.

Current outputs favour the cold to win but with the boundary of the 2 airmasses over us we are likely to see some ebbing and flowing over the next few runs.

 

Let's hope the push from the east continues to look the stronger.

Edited January 8, 2014 by phil nw.

[Ali1977]

GFS ens update around 0600/1200/1800/0000 I think. They start running once the GFS Op finishes.

[nick sussex]

Regardless of what the UKMO might say publicly they will have noted the possibility of disruptive snow and given warning to those agencies who need to know ahead of time.

 

With a Scandi high to the ne and trough disruption close to the UK then you're always liable to have a snowy boundary between the two airmasses, I know they have a difficult job and won't mention much until nearer the time but any forecaster at the HQ will have noted the possibilities.

 

Longer term yes the means may suggest the jet over the top but its too far ahead and much depends on the upstream pattern which at least for the timebeing is supposed to transition to a faster flow but with still some amplitude:

 

THE MEDIUM RANGE PERIOD WILL FEATURE A RE-BUILDING OF THE ERNPAC/WEST COAST MEAN RIDGE WITH A DOWNSTREAM TROUGH THAT SHOULDHEAD FROM THE W-CNRL US SUN/MON TO THE ERN STATES TUE/WED.  MODELAND ENSEMBLE MEAN AGREEMENT WITH THE LARGE SCALE PATTERN IS QUITEGOOD THROUGH THE NEXT SEVEN DAYS BUT SIGNIFICANT EMBEDDED SYSTEMDETAIL/TIMING DIFFS REMAIN...LENDING PREFERENCE FOR AN ENSEMBLEMEAN FORECAST APPROACH.  WPC MEDIUM RANGE GUIDANCE HAS BEENPRIMARILY DERIVED FROM THE ECMWF ENSEMBLE MEAN.  THIS MEAN INPARTICULAR HAS BEEN OFFERING BEST CONTINUITY WITH A SLIGHTLY MOREAMPLIFIED FLOW PATTERN OVER NOAM THAT SEEMS TO BETTER FIT PACIFICUPSTREAM FLOW TRENDS

 

The latter important as originally NOAA mentioned a non correlation between what they were seeing in the Pacific and the pattern over the USA, basically teleconnections said one thing and the models the other, the flow was too flat in their opinion, you can then trace this back because its as the models added more amplification over there at least for the initial key central USA wave that this began to feed down into western Europe with the pulling away further now of lower heights and the westwards corrections and more negatively tilted troughing.

[winterof79]

If we get ANY extension of heights towards Greenland then you can forget zonal for the rest of the month. It would be goodnight Vienna for it. However if we don't see this it's perfectly plausible that the E'ly could be a relatively short lived affair.

 

Heights towards Greenland...

 

 

 

GEM and ECM are quite similar around the120 mark in that both send low heights under the forming block

http://www.meteociel.fr/modeles/ecmwf/runs/2014010800/ECH1-120.GIF?08-12

http://modeles.meteociel.fr/modeles/gem/runs/2014010800/gemnh-0-120.png?00

GEM then reinforces that with a second slider which allows heights to forge westward toward Iceland/Greenland

http://modeles.meteociel.fr/modeles/gem/runs/2014010800/gemnh-0-162.png?00

ECM  stalls this feature at the moment

http://www.meteociel.fr/modeles/ecmwf/runs/2014010800/ECH1-168.GIF?08-12

Can UKMO follow GEM http://www.meteociel.fr/ukmo/runs/2014010800/UN144-21.GIF?08-06 tantilising thought

Edited January 8, 2014 by winterof79